Free/Open Source Photography on PIXLS.US

Darktable 3:RGB or Lab? Which Modules? Help!

Sun, 26 Jan 2020 00:00:00 +0000

Original post in French by Aurélien PIERRE , edited by the pixls community.

Darktable is slowly converging to a scene-referred RGB workflow. Why is that? What does it involve? How does the use of darktable change? Answers here…

This article begins with a 3 section introduction of the Lab space. You don’t need to understand it in detail in order to understand what happens next.

What is Lab?

The color space CIE Lab was published in 1976 by the International Commission on Illumination (CIE), in an attempt to mathematically describe the color perception of the average human being. Lab space aims to decouple the brightness information (L channel) from the chroma information (channels a and b) and takes into account the non-linear corrections that the human brain makes to the linear signal it receives from the retina. Lab space is derived from CIE XYZ space , which represents the physiological response of 3 of the 4 types of photo-sensitive cells in the retina (the cones).

G'MIC 2.7 - Process Your Images with Style!

Fri, 06 Sep 2019 00:00:00 +0000

The IMAGE team at the GREYC research laboratory is pleased to announce the release of version 2.7 of G’MIC (GREYC’s Magic for Image Computing), its free, generic, extensible, and probably a little magical, framework for digital image processing .

The previous PIXLS.US article on this open-source framework was published a year ago, in August 2018. This new release is therefore a good opportunity to summarize the main features and milestones of the project’s life over the past twelve months. Fasten your seat belts, the road is long and full of surprises!

Quick digiKam Tip: Back up digikamrc file

Tue, 09 Jul 2019 00:00:00 +0000

digiKam stores the current state of the application in the ~/.config/digikamrc file. This file keeps track of pretty much everything: from the database connection profile and custom toolbar settings, to the last-used curve and sharpening parameters. So next time you install or reinstall digiKam, don’t forget to back up the digikamrc file. This way, you don’t have to configure a fresh digiKam installation from scratch. Simply copy the file to a safe location or external storage device, and drop the file into the ~/.config folder before you run digiKam.

Location Tracking for Photographers with GPS Logger and Trekarta

Fri, 28 Jun 2019 00:00:00 +0000

When it comes to Android apps for photographers, we are spoiled for choice. From depth-of-field and golden hour calculators to sun position and remote control apps – there are plenty of clever tools to choose from. But there is one particular app combination that can prove to be indispensable for any photographer on the move: a GPS logger and a GPX viewer. There are two main reasons for that.

Processing a nightscape in Siril

Tue, 16 Apr 2019 09:08:28 -0600

Siril is a program for processing astronomical photographs.

In this tutorial, I’ll show you how to process a nightscape in Siril 0.9.10.

It doesn’t intend to be comprehensive tutorial but rather to present a basic general workflow that is a good starting point for those who want to learn Siril.

For this purpose, I’m sharing the raw files I used for the image I presented here , except that for this tutorial I limited the number of frames for the sake of bandwidth and processing speed.

New Topic Previews

Tue, 02 Apr 2019 12:18:10 -0500

I’ve been a member of the community over at blenderartists.org (previously elysiun) for a long time (it’ll be 15 years this October according to my profile there ). So it was nice to see when they finally transitioned to using Discourse a little while back.

G'MIC Finally Accepts Donations

Sat, 23 Mar 2019 12:06:10 -0500

For years the incredible team over at G’MIC (GREYC’s Magic for Image Computing) have been producing an incredible image processing system and many awesome filters to go along with it. They’ve got an very active and awesome community right here on their forums and they’ve been producing all manner of neat processing filters for photographers, digital artists, and scientists.

Due to the project being under the auspices of a French Research Lab, the GREYC laboratory in Caen, France, they were limited in being able to accept any donations.

Until now!

To avoid burying the lede, go and make a donation to the fabulous folks of the G’MIC project: https://libreart.info/en/projects/gmic .

A Q&A with the CHDK Developers

Sun, 17 Feb 2019 14:11:42 -0600

Introduction

CHDK is a free, open source software add-on that runs on Canon PowerShot cameras and expands their functionality. Some of its features are:

Professional control: RAW files, bracketing, manual control over exposure, zebra mode, live histogram, grids, etc.
Motion detection: Trigger exposure in response to motion, fast enough to catch lightning.
USB remote: Simple DIY remote allows you to control your camera remotely.
Scripting: Control CHDK and camera features using uBASIC and Lua scripts. Enables time lapse, motion detection, advanced bracketing, and more.
PTP: Shooting control, live view, and file transfer from Linux and Windows.

I talked with the core team of developers to learn more about CHDK.

Libre Graphics Meeting 2019

Sun, 06 Jan 2019 09:59:40 -0600

It’s that time of year again: Libre Graphics Meeting 2019 is fast approaching!

This year the meeting will be May 29 to June 2 in Saarbrücken, Germany . This is extra exciting because Saarbrücken is centrally located enough that we should have a nice representation from projects and community members. Members of both RawTherapee and darktable live nearby and will be in attendance (along with others from those projects and many others).

Goodbye Google Analytics

Mon, 31 Dec 2018 15:16:40 -0600

Over on my personal website I decided to stop using third party trackers and assets to keep from exposing visitors to unintended tracking. Third party assets expose a user to being tracked and analyzed by those third (or fourth, or more) parties and honestly this is something the web could use a little (lot) less of. I loved having stats early on when we started this crazy idea for a community and as I mentioned on my blog post, it’s a Faustian bargain to get stats at the expense of allowing Google to track what all the users of the site are doing. No thanks.

2018 PlayRaw Calendar

Sun, 25 Nov 2018 09:10:06 -0600

Last year I got an amazing surprise in the mail. It was an awesome calendar of a handpicked selection of results from the years PlayRaw images.

Chris (@chris) put together another fantastic calendar for this year (while juggling kids, too) and it’s too nice to not have a post about it!

Yep, that's the back side. _Monkey Business_ by Dimitrios Psychogios (cba)

Giving More Thanks

Thu, 22 Nov 2018 10:20:28 -0600

It is a yearly tradition for us to post something giving thanks around this holiday. I think it’s because this community has become such a large part of our lives. Also, I think it helps to remind ourselves once in a while of the good things that happen to us. So in that spirit…

Financial Supporters

We are lucky enough (for now) to not have huge costs, but they are costs none-the-less. We have been very fortunate that so many of you have stepped up to help pay those costs.

Create lens calibration data for lensfun

Thu, 15 Nov 2018 08:00:00 -0500

[Article updated on: 2019-12-09]

Introduction

All photographic lenses have several types of errors. Three of them can be corrected by software almost losslessly: distortion , transverse chromatic aberration (TCA) , and vignetting . The Lensfun library provides code to do these corrections. Lensfun is not used by the photographer directly. Instead, it is used by a photo raw development software such as darktable or RawTherapee. For example, if you import a RAW into darktable, darktable detects the lens model, focal length, aperture and focal distance used for the picture, and it then calls Lensfun to automatically correct the photograph.

Support Andrea Ferrero on Patreon!

Wed, 26 Sep 2018 10:22:32 -0800

Andrea Ferrero, or as we know him Carmelo_DrRaw , has been contributing to the PIXLS.US community since April of 2015. A self described developer and photography enthusiast, Andrea is the developer of the PhotoFlow image editor, and is producing AppImages for:

The GIMP image manipulation program - weekly AppImage packages from stable releases and development branches.
The RawTherapee editor - nightly AppImage and Windows packages from stable and development branches
LuminanceHDR - nightly AppImage packages for Linux
HDRMerge - nightly AppImage packages for Linux
The Hugin panorama photo stitcher - AppImages for stable releases and development branches

Andrea is the best sort of community member, contributing six different projects (including his own)! He is always thoughtful in his responses, does his own support for PhotoFlow, and is kind and giving. He has finally started a Patreon page to support his all of his hard work . Support him now!

G'MIC 2.3.6

Wed, 29 Aug 2018 10:39:18 -0500

The IMAGE team of the GREYC laboratory is happy to celebrate the 10th anniversary of G’MIC with you, an open-source (CeCILL ), generic and extensible framework for image processing . GREYC is a public research laboratory on digital technology located in Caen, Normandy/France, under the supervision of 3 research institutions: the CNRS (UMR 6072), the University of Caen Normandy and the ENSICAEN engineering school.

From Russia with Love

Mon, 23 Jul 2018 16:03:11 -0600

Ilya Varivchenko is a fashion and portrait photographer from Ivanovo, Russian Federation. He’s a UNIX administrator with a long-time passion for photography that has now become a second part-time job for him. Working on location and in his studio, he’s been producing a wonderful body of work specializing in portraiture, model tests, and more.

He’s a member of the community here (@viv), and he was kind enough to spare some time and answer a few questions (plus it gives me a good excuse to showcase some of his great work!).

Welcoming the gPhoto Project to the PIXLS.US community!

Wed, 11 Jul 2018 10:22:32 -0800

A major goal of the PIXLS.US effort is to do whatever we can do to help developers of projects unburden themselves from administrating their project. We do this, in part, by providing forum hosting, participating in support, providing web design, and doing community outreach. With that in mind, we are excited to welcome the gPhoto Projects to our discuss forum !

(NSFW) What Stefan Sees

Fri, 04 May 2018 14:11:42 -0600

Stefan Schmitz is a photographer living in Northern France and specializing in sensual and nude portraits. I stumbled upon his work during one of my searches for photographers using Free Software on Flickr , and as someone who loves shooting portraits his work was an instant draw for me.

Franzi Skamet by Stefan Schmitz

Khiara Gray by Stefan Schmitz

Profiling a camera with darktable-chart

Wed, 25 Apr 2018 19:00:07 -0500

[Article updated on: 2019-06-18]

What is a camera profile?

A camera profile is often a combination of a color lookup table (LUT) and a tone curve which is applied to a RAW file to get a developed image. It translates the colors that a camera captures into the colors they should look like. If you shoot in RAW and JPEG at the same time, the JPEG file is already a developed picture. Your camera can do color corrections to the data it gets from the sensor when developing a picture. In other words, if a certain camera tends to turn blue into turquoise, the manufacturers internal profile will correct for the color shift and convert those turquoise values back to their proper hue.

How to create camera noise profiles for darktable

Sun, 15 Apr 2018 19:00:07 -0500

[Article updated on: 2019-11-26]

What is noise?

Noise in digital images is similar to film grain in analogue photography. In digital cameras, noise is either created by the amplification of digital signals or heat produced by the sensor. It appears as random, colored speckles on an otherwise smooth surface and can significantly degrade image quality.

Noise is always present, and if it gets too pronounced, it detracts from the image and needs to be mitigated. Removing noise can decrease image quality or sharpness. There are different algorithms to reduce noise, but the best option is if having profiles for a camera to understand the noise patterns a camera model produces.

G'MIC 2.2

Wed, 21 Feb 2018 15:18:32 -0600

The IMAGE team of the GREYC laboratory (UMR CNRS 6072, Caen, France) is pleased to announce the release of a new 2.2 version of G’MIC , its open-source, generic, and extensible framework for image processing . As we already did in the past , we take this opportunity to look at the latest notable features added since the previous major release (2.0, last June).

LGM and Libre Graphics at SCaLE 16x

Tue, 12 Dec 2017 15:24:39 -0600

There are two libre graphics related meetings coming up early next year. The annual Libre Graphics Meeting (in Spain this year), and something entirely new: a libre graphics track at SCaLE. How exciting!

Libre Graphics Meeting 2018

The Libre Graphics Meeting is going to be in Seville, Spain this year. They recently published their Call for Participation and are accepting presentation and talk proposals now. Unfortunately, I won’t be able to attend this year, but there’s a pretty good chance some friendlier folks from the community will be! We’ll update more about who will be making it out as soon as we know, and maybe we can convince someone to run another photowalk with everyone. (On a side note, if anyone from the community is going to make it and wants a hand putting anything together for a presentation just let us know - we’re here to help.)

Simple Exposure Mapping in GIMP

Tue, 05 Dec 2017 09:17:37 -0600

There are many different approaches to blending exposures in the various projects , and they can range from extremely detailed and complex to quick and simple. Today we’re going to look at the latter.

I was recently lucky enough to attend an old friends wedding in upstate NY. Mairi got married! (For those not familiar with her, she’s the model from An Open Source Portrait as well as A Chiaroscuro Portrait tutorials.)

Mairi's chiaroscuro portrait.

I had originally planned on celebrating with everyone and wrangling my two kids, so I left my camera gear at home. Turns out Mairi was hoping that I’d be shooting photos. Not wanting to disappoint, I quickly secured a kit from a local rental shop. (Thank goodness for friends new and old to help wrangle a very busy 2 year old.)

Giving Thanks

Wed, 22 Nov 2017 10:20:28 -0600

This is becoming a sort of tradition for me to post something giving thanks around this holiday. I think it’s because this community has become such a large part of my life (even if I don’t have nearly as much time to spend on it as I’d like). Also, I think it helps to remind ourselves once in a while of the good things that happen to us. So in that spirit…

Faces of Open Source

Tue, 17 Oct 2017 13:20:28 -0600

Recently, @houz posted about an amazing project by photographer Peter Adams called Faces of Open Source .

Peter really (ahem) throws a light on many amazing luminaries from not only the Free/Open Source Software community, but in some cases the history and roots of all modern computing. He has managed to coordinate portrait sessions with many people that may be unassuming to a layperson, but take a moment to read any of the short bios on the site and the gravity of the contributions from the subjects to modern computing becomes apparent.

Keep the Raws Coming

Fri, 29 Sep 2017 00:00:00 +0000

Our friendly neighborhood @LebedevRI pointed out to me a little while ago that we had reached some nice milestones for https://raw.pixls.us . Not surprisingly I had spaced out and not written anything about it (or really any sort of social posts). Bad Pat!

So let’s talk about raw.pixls.us (RPU) a bit!

Recap

For anyone not familiar with RPU, a quick recap (we had previously written about raw.pixls.us earlier this year). There used to be a website for housing a repository of raw files for as many digital cameras as possible called rawsamples.ch . It was created by Jakob Rohrbach and had been running since March of 2007. Back in 2016 the site was hit with a SQL injection attack that left the Joomla database corrupted (in a teachable moment, the site also didn’t have a database backup).

G'MIC 2.0

Thu, 08 Jun 2017 10:22:52 -0600

The IMAGE team of the research laboratory GREYC in Caen/France is pleased to announce the release of a new major version (numbered 2.0) of its project G’MIC : a generic, extensible, and open source framework for image processing . Here, we present the main advances made in the software since our last article . The new features presented here include the work carried out over the last twelve months (versions 2.0.0 and 1.7.x, for x varying from 2 to 9).

Happy 2nd Birthday Discuss

Fri, 12 May 2017 15:20:34 -0600

I was idling in our IRC chat room earlier when @Morgan_Hardwood wished us all a “Happy Discuss Anniversary”. Wouldn’t you know it, another year slipped right by! (Surely there’s no way it could already be a year since the last birthday post ? Where does the time go?)

We’ve had a bunch of neat things happen in the community over the past year! Let’s look at some of the highlights.

Welcome digiKam!

Wed, 03 May 2017 14:44:35 -0600

One of the goals we have here at PIXLS.US is to help Free Software projects however we can, and one of those ways is to focus on things that we can do well that might help make things easier for the projects. It may not be much fun for project developers to deal with websites or community outreach necessarily. This is something I think we can help with, and recently we had an opportunity to do just that with the awesome folks over at the photo management project digiKam .

GIMP is Going to LGM!

Wed, 29 Mar 2017 15:51:36 -0600

This years Libre Graphics Meeting (2017) is going to be held in the lovely city seen above, Rio de Janeiro, Brazil! This is an important meeting for so many people in the Free/Libre art community as it’s one of the only times they have an opportunity to meet face to face.

We’ve had some folks attending the past LGM’s (Leipzig and London ) and it’s a wonderful opportunity to spend some time with friends. (Also, @frd from the community will be there!)

RawTherapee and Pentax Pixel Shift

Fri, 24 Mar 2017 13:17:10 -0600

What is Pixel Shift?

Modern digital sensors (with a few exceptions) use an arrangement of RGB filters over a square grid of photosites. For a given 2x2 square of photosites the filters are designed to allow two green, and one each red and blue colors through to the photosite. These are arranged on a grid:

The pattern is known as a Bayer pattern (after the creator Bryce Bayer of Eastman Kodak). The resulting pattern shows how each RGB is offset into the grid.

Find us at SCaLE 15x

Mon, 27 Feb 2017 00:00:00 +0000

The Southern California Linux Expo (SCaLE) 15x is returning to the Pasadena Convention Center on March 2-5, 2017. SCaLE is one of the largest community-organized conferences in North America, with some 3,500 attendees last year.

If you’re attending the conference this year, find me, @paperdigits and lets talk shop or grab a meal!

Don't judge me, it was the morning.

You can ping me on the [forum](https://discuss.pixls.us), [on twitter](https://twitter.com/paperdigits), or on Matrix/riot.im at @paperdigits:matrix.org.

If meeting isn’t enough for you, I’ll have stickers!

From the Community Vol. 2

Fri, 10 Feb 2017 00:00:00 +0000

Welcome to the second installment of From the Community, a (hopefully) quarterly-ish blog post to highlight a few of the things our community members have been doing!

Improving grain simulation

@arctic has posted some research about how to better simulate grain in our digital images and the ensuing conversation is both fascinating and way above my head! This discussion is thus far raw processor independent and more input and code is welcome!

New Year, New Raw Samples Website

Thu, 12 Jan 2017 11:10:38 -0600

Happy New Year, and I hope everyone has had a wonderful holiday!

We’ve been busy working on various things ourselves, including migrating RawPedia to a new server as well as building a replacement raw sample database/website to alleviate the problems that rawsamples.ch was having…

rawsamples.ch Replacement

Rawsamples.ch is a website with the goal to:

…provide RAW-Files of nearly all available Digitalcameras mainly to software-developers. [sic]

It was created by Jakob Rohrbach and had been running since March 2007, having amassed over 360 raw files in that time from various manufacturers and cameras. Unfortunately, back in 2016 the site was hit with a SQL-injection that ended up corrupting the database for the Joomla install that hosted the site. To compound the pain, there were no database backups… :(

Welcome Digital Painters

Mon, 05 Dec 2016 15:50:29 -0600

Yes, there really is art outside photography. :)

The history and evolution of painting has undergone a similar transformation as most things adapting to a digital age. As photographers, we adapted techniques and tools commonly used in the darkroom to software, and found new ways to extend what was possible to help us achieve a vision. Just as we tried to adapt skills to a new environment, so too did traditional artists, like painters.

A Masashi Wakui look with GIMP

Mon, 28 Nov 2016 13:25:21 -0600

This tutorial explains how to achieve an effect based on the post processing by photographer Masashi Wakui . His primary subjects appear as urban landscape views of Japan where he uses some pretty and aggressive color toning to complement his scenes along with a soft ‘bloom’ effect on the highlights. The results evoke a strong feeling of an almost cyberpunk or futuristic aesthetic (particularly for fans of Bladerunner or Akira !).

Giving Thanks

Tue, 22 Nov 2016 10:16:49 -0600

Here in the U.S., we have a big holiday coming up this week: Thanksgiving . Serendipitously, this holiday also happens to fall when a few neat things are happening around the community, and what better time is there to recognize some folks and to give thanks of our own? No time like the present!

A Special Thanks

I feel a special “Thank You” should first go to a photographer and fantastic supporter of the community, Dimitrios Psychogios . Last year for our trip to Libre Graphics Meeting, London he stepped up with an awesome donation to help us bring some fun folks together.

João Almeida's darktable Presets

Mon, 14 Nov 2016 12:19:19 -0600

I realize that I’m a little late to this, but photographer João Almeida has created a wonderful set of film emulation presets for darktable that he uses in his own workflow for personal and commisioned work. Even more wonderful is that he has graciously released them for everyone to use .

These film emulations started as a personal side project for João, and he adds a disclaimer to them that he did not optimize them all for each brand or model of his cameras. His end goal was for these to be as simple as possible by using a few darktable modules. He describes it best on his blog post about them :

Aligning Images with Hugin

Fri, 04 Nov 2016 13:12:04 -0600

Hugin is an excellent tool for for aligning and stitching images. In this article, we’ll focus on aligning a stack of images. Aligning a stack of images can be useful for achieving several results, such as:

bracketed exposures to make an HDR or fused exposure (using enfuse/enblend), or manually blending the images together in an image editor
photographs taken at different focal distances to extend the depth of field, which can be very useful when taking macros
photographs taken over a period of time to make a time-lapse movie

For the example images included with this tutorial, the focal length is 12mm and the focal length multiplier is 1. A big thank you to @isaac for providing these images.

The Royal Photographic Society Journal

Wed, 02 Nov 2016 10:36:20 -0400

The Journal of the Photographic Society is the journal for one of oldest photographic societies in the world: the Royal Photographic Society . First published in 1853, the RPS Journal is the oldest photographic periodical in the world (just edging out the British Journal of Photography by about a year).

So you can imagine my doubt when confronted with an email about using some material from pixls.us for their latest issue…

If the name sounds familiar to anyone it may be from a recent post by Joe McNally who is featured prominently in the September 2016 issue. He was also just inducted as a fellow into the society!

Arnold Newman Portraits

Fri, 28 Oct 2016 12:39:58 -0500

Anyone that has spent any time around me would realize that I’m particularly fond of portraits. From the wonderful works of Martin Schoeller to the sublime Dan Winters , I am simply fascinated by a well executed portrait. So I thought it would be fun to take a look at some selections from the “father” of environmental portraits - Arnold Newman .

[Arnold Newman][newman], Self Portrait, Baltimore MD, 1939

Newman wanted to become a painter before needing to drop out of college after only two years to take a job shooting portraits in a photo studio in Philadelphia. This experience apparently taught him what he did not want to do with photography…

Highlight Bloom and Photoillustration Look

Wed, 12 Oct 2016 13:47:35 -0500

Over in the forums community member Sebastien Guyader (@sguyader) posted a neat workflow for emulating a photo-illustrative look popularized by photographers like Dave Hill where the resulting images often seem to have a sort of hyper-real feeling to them. Some of this feeling comes from a local-contrast boost and slight ‘blooming’ of the lighter tones in the image (though arguably most of the look is due to lighting and compositing of multiple elements).

From the Community Vol. 1

Sun, 04 Sep 2016 00:00:00 +0000

Welcome to the first installment of From the Community, a (hopefully) quarterly blog post to highlight a few of the things our community members have been doing!

Rapid Photo Downloader Process Model

@damonlynch has a great write up of Rapid Photo Download’s process model . Rapid Photo Downloader is built using Python , so if you’re looking for a good way to add threads to your Python program, this write up has some good information for you, check it out!

A Chiaroscuro Portrait

Wed, 27 Jul 2016 13:16:07 -0500

Introduction (Concept/Theory)

The term Chiaroscuro is derived from the Italian chiaro meaning ‘clear, bright’ and oscuro meaning ‘dark, obscure’. In art the term has come to refer to the use of bold contrasts between light and shadow, particularly across an entire composition, where they are a prominent feature of the work.

This interplay of shadow and light is particularly important in allowing the viewer to extrapolate volume from a flat image. The use of a single light source helps to accentuate the perception of volume as well as adding drama and dynamics to the scene.

HD Photo Slideshow with Blender

Tue, 12 Jul 2016 08:36:55 -0500

While I was out at Texas Linux Fest this past weekend I got to watch a fun presentation from the one and only Brian Beck . He walked through an introduction to Blender , including an overview of creating his great The Lady in the Roses image that was a part of the 2015 Libre Calendar project.

Coincidentally, during my trip home community member @Fotonut asked about software to create an HD slideshow with images. The first answer that jumped into my mind was to consider using Blender (a very close second was OpenShot because I had just spent some time talking with Jon Thomas about it).

Texas Linux Fest 2016

Mon, 04 Jul 2016 06:48:16 -0500

While in London this past April I got a chance to hang out a bit with LWN.net editor and fellow countryman, Nathan Willis . (It sounds like the setup for a bad joke: “An Alabamian and Texan meet in a London pub…”). Which was awesome because even though we were both at LGM2014, we never got a chance to sit down and chat.

So it was super-exciting for me to hear from Nate about possibly doing a photowalk and Free Software photo workshop at the 2016 Texas Linux Fest , and as soon as I cleared it with my boss, I agreed!

Color Manipulation with the Colour Checker LUT Module

Wed, 29 Jun 2016 08:44:08 -0500

I was lucky to get to spend some time in London with the darktable crew. Being the wonderful nerds they are, they were constantly working on something while we were there. One of the things that Johannes was working on was the colour checker module for darktable.

Having recently acquired a Fuji camera, he was working on matching color styles from the built-in rendering on the camera. Here he presents some of the results of what he was working on.

Sharing is Caring

Wed, 22 Jun 2016 10:10:14 -0500

It was always my intention to make the entire PIXLS.US website available under a permissive license. The content is already all licensed Creative Commons, By Attribution, Share-Alike (unless otherwise noted). I just hadn’t gotten around to actually posting the site source.

Until now(ish). I say “ish” because I apparently released the code back in April and am just now getting around to talking about it.

Also, we finally have a category specifically for all those darktable weenies on discuss !

Sharing Galore

Tue, 21 Jun 2016 12:30:29 -0600

Community member and RawTherapee hacker Morgan Hardwood brings us a great tutorial + assets from one of his strolls near the Söderåsen National Park (Sweden!). Ofnuts is apparently trying to get me to burn the forum down by sharing his raw file of a questionable subject. After bugging David Tschumperlé he managed to find a neat solution to generating a median (pixel) blend of a large number of images without making your computer throw itself out a window.

Display Color Profiling on Linux

Thu, 09 Jun 2016 16:50:08 -0600

This article by Pascal de Bruijn was originally published on his site and is reproduced here with permission. —Pat

Attention: This article is a work in progress, based on my own practical experience up until the time of writing, so you may want to check back periodically to see if it has been updated.

This article outlines how you can calibrate and profile your display on Linux, assuming you have the right equipment (either a colorimeter like for example the i1 Display Pro or a spectrophotometer like for example the ColorMunki Photo). For a general overview of what color management is and details about some of its parlance you may want to read this before continuing.

New Rapid Photo Downloader

Sun, 22 May 2016 00:00:00 +0000

Community member Damon Lynch happens to make an awesome program called Rapid Photo Downloader in his “spare” time. In fact you may have heard mention of it as part of Riley Brandt’s “The Open Source Photography Course” ^*. It is a program that specializes in downloading photo and video from media in as efficient a manner as possible while extending the process with extra functionality.

^* Riley donates a portion of the proceeds from his course to various projects, and Rapid Photo Downloader is one of them!

G'MIC 1.7.1

Wed, 18 May 2016 00:00:00 +0000

A new version 1.7.1 “Spring 2016” of G’MIC (GREYC’s Magic for Image Computing), the open-source framework for image processing, has been released recently (26 April 2016). This is a great opportunity to summarize some of the latest advances and features over the last 5 months.

G’MIC: A brief overview

G’MIC is an open-source project started in August 2008. It has been developed in the IMAGE team of the GREYC laboratory from the CNRS (one of the major French public research institutes). This team is made up of researchers and teachers specializing in the algorithms and mathematics of image processing. G’MIC is released under the free software licence CeCILL (GPL-compatible) for various platforms (Linux, Mac and Windows). It provides a set of various user interfaces for the manipulation of generic image data, that is images or image sequences of multispectral data being 2D or 3D, and with high-bit precision (up to 32bits floats per channel). Of course, it manages “classical” color images as well.

Post Libre Graphics Meeting

Fri, 29 Apr 2016 16:12:46 -0600

What a blast!

This trip report is long overdue, but I wanted to process some of my images to share with everyone before I posted.

It had been a couple of years since I had an opportunity to travel and meet with the GIMP team again (Leipzig was awesome) so I was really looking forward to this trip. I missed the opportunity to head up to the great white North for last years meeting in Toronto.

Pre-LGM Photowalk

Fri, 08 Apr 2016 15:41:36 -0600

It’s that time of year again! The weather is turning mild, the days are smelling fresh, and a bunch of photography nerds are all going to get together in a new country to roam around and (possibly) annoy locals by taking a ton of photographs! It’s the Pre-Libre Graphics Meeting photowalk of 2016!

Come join us the day before LGM kicks off to have a stroll through a lovely park and get a chance to shoot some photos between making new friends and having a pint.

Happy Birthday DISCUSS.PIXLS.US

Wed, 06 Apr 2016 10:01:30 -0600

For some reason I was checking my account on the forums earlier today and noticed that it was created in April, 2015. On further inspection it looks like my, and @darix, accounts were created on April 2^nd 2015.

(Not to be confused with the main site because apparently it took me about 8 months to get a forum stood up…)

Which means that the forums have been around for just over a year now?!

Lighting Diagrams

Mon, 04 Apr 2016 16:23:36 -0600

Community member Eric Mesa asked on the forums the other day if there might be some Free resources for photographers that want to build a lighting diagram of their work. These are the diagrams that show how a shot might be set up with the locations of lights, what types of modifiers might be used, and where the camera/photographer might be positioned with respect to the subject. These diagrams usually also include lighting power details and notes to help the production.

PlayRaw (Again)

Mon, 21 Mar 2016 16:00:45 -0600

On the old RawTherapee forums they used to have a contest sharing a single raw file amongst the members to see how everyone would approach processing from the same starting point. They called it PlayRaw. This seemed to really bring out some great work from the community so I thought it might be fun to start doing something similar again here.

I took a (relatively) recent image of Mairi and decided to see how it would be received (I’d say fairly well given the responses). This was my result from the raw file that I called Mairi Troisième :

Shimming an Adapter to be Parallel

Fri, 11 Mar 2016 13:03:48 -0600

Some of you may know I exclusively use Contax manual focus lenses on my Canon cameras. I have had one reliable adapter from the start, that just happened to be perfect in every way: perfectly parallel, and lets my lenses focus exactly to infinity, and none of my lenses hit the mirror on my 5D.

However, swapping adapters between cameras gets mighty tedious, so recently I have been trying a variety of different adapters for my cameras, several quality tiers ranging from the cheapest ($15) up to the most expensive ($70).

jpeg2RAW Guest Spot

Sat, 20 Feb 2016 13:54:54 -0600

Mike Howard , the host and creator of the jpeg2RAW podcast reached out to me last week to see if I might be able to come on the show to talk about Free Software Photography and what we’ve been up to here. One of the primary reasons for creating this site was to be able to raise awareness of the Free Software community to a wider audience.

So this is a great opportunity for us to expose ourselves!

HDR Photography with Free Software (LuminanceHDR)

Tue, 26 Jan 2016 14:57:59 -0500

I have a mostly love/hate relationship with HDR images (well, tonemapping HDR more than the HDR themselves). I think the problem is that it’s very easy to create really bad HDR images that the photographer thinks look really good. I know because I’ve been there:

Don't judge me, it was a weird time in my life...

The best term I’ve heard used to describe over-processed images created from an HDR is “clown vomit” (which would also be a great name for a band, by the way). They are easily spotted with some tell-tale signs such as the halos at high-contrast edges, the unrealistically hyper-saturated colors that make your eyes bleed, and a general affront to good taste. In fact, while I’m putting up embarrassing images that I’ve done in the past, here’s one that scores on all the points for a crappy image from an HDR:

Libre Graphics Meeting London

Fri, 08 Jan 2016 09:36:06 -0500

We’re heading to London!

I missed LGM last year in Toronto (having a baby - well, my wife was). I am going to be there this year for LGM/London !

Help Support Us

I don’t ever do this normally, but you’ve got to start somewhere, right?

It’s my long-term desire to be able to hold a PIXLS meetup/event every year where the community can get together. Where we can hold workshops, photowalks, and generally share knowledge and information. For free, for anyone.

darktable 2.0

Thu, 24 Dec 2015 21:56:56 -0500

Sneaking a release out on Christmas Eve, the darktable team have announced their feature release of darktable 2.0 ! After quite a few months of Release Candidates the 2.0 is finally here. Please join me in saying Congratulations and a hearty Thank You! for all of their work bringing this release to us.

Alex Prokoudine of Libre Graphics World has a more in-depth look at the release including a nice interview with part of the team: Johannes Hanika, Tobias Ellinghaus, Roman Lebedev, and Jeremy Rosen. My favorite tidbit from the interview:

Let's Encrypt!

Tue, 15 Dec 2015 13:53:26 -0500

I finally got off my butt to get a process in place to obtain and update security certificates using Let’s Encrypt for both pixls.us and discuss.pixls.us . I also did some (more) work with Victor Grigas and Wikipedia to support their #Edit2015 video this year.

Wikipedia #Edit2015

Last year, I did some 2.5 parallax animations for Wikipedia to help with their first-ever end-of-the-year retrospective video (see the blog post from last year ). Here is the retrospective from #Edit2014:

Users Guide to High Bit Depth GIMP 2.9.2, Part 2

Wed, 02 Dec 2015 12:00:00 -0600

This is Part 2 of a two-part guide to high bit depth editing in GIMP 2.9.2 with Elle Stone. The first part of this article can be found here: [*Part 1*](/articles/users-guide-to-high-bit-depth-gimp-2-9-2-part-1/).

Using GIMP 2.9.2 for radiometrically correct editing

<ol>
<li><a href="#linearized-srgb-channel-values-and-radiometrically-correct-editing">Linearized sRGB channel values and radiometrically correct editing</a></li>
<li><a href="#using-the-linear-light-option-in-the-image-precision-menu">Using the “Linear light” option in the “Image/Precision” menu</a></li>
<li><a href="#a-note-on-interoperability-between-krita-and-gimp">A note on interoperability between Krita and GIMP</a></li>
</ol>

GIMP 2.9.2’s unbounded floating point ICC profile conversions (handle with care!)

Using GIMP 2.9.2’s floating point precision for unclamped editing

<ol>
<li><a href="#high-bit-depth-gimp-s-unclamped-editing-a-whole-realm-of-new-editing-possibilities">High bit depth GIMP’s unclamped editing: a whole realm of new editing possibilities</a></li>
<li><a href="#if-the-thought-of-working-with-unclamped-rgb-data-is-unappealing-use-integer-precision">If the thought of working with unclamped RGB data is unappealing, use integer precision</a></li>
</ol>

Looking to the future: GIMP 3.0 and beyond

Radiometrically correct editing

Linearized sRGB channel values and radiometrically correct editing

One goal for GIMP 2.10 is to make it easy for users to produce radiometrically correct editing results. "Radiometrically correct editing" reflects the way light and color combine out there in the real world, and so requires that the relevant editing operations be done on linearized RGB.

Happy Birthday GIMP!

Wed, 25 Nov 2015 08:25:15 -0500

I got busy building a birthday present for a project I work with and all sort of neat things happened in my absence! The Ubuntu Free Culture Showcase chose winners for it’s wallpaper contest for Ubuntu 15.10 ‘Wily Werewolf’ (and quite a few community members were among those chosen).

The darktable crew is speeding along to a 2.0 release with a new RC2 being released .

Also, a great big HAPPY 20^th BIRTHDAY GIMP ! I made you a present. I hope it fits and you like it! :)

News from the World of Tomorrow

Mon, 02 Nov 2015 08:50:17 -0500

Some awesome updates from the community and activity over on the forums ! People have been busy doing some really neat things (that really never fail to astound me). The level of expertise we have floating around on so many topics is quite inspiring.

darktable 2.0 Release Candidate

Towards a Better darktable!

A nice Halloween weekend gift for the F/OSS photo community from darktable : a first Release Candidate for a 2.0 release is now available!

Users Guide to High Bit Depth GIMP 2.9.2, Part 1

Sun, 01 Nov 2015 12:00:00 -0600

Introduction: high bit depth GIMP 2.9.2

    <ol>
    <li><a href="#purpose-of-this-guide">Purpose of this guide</a></li>
    <li><a href="#useful-links-the-official-gimp-website-builds-for-windows-and-mac-building-gimp-on-linux">Useful links: the official GIMP website, builds for Windows and MAC, building GIMP on Linux</a></li>
    <li><a href="#editing-in-srgb-vs-editing-in-other-color-spaces">Editing in sRGB vs editing in other color spaces</a></li>
    <li><a href="#a-note-about-the-gamma-hack-that-s-provided-for-many-editing-operations">A note about the “Gamma hack” that’s provided for many editing operations</a></li>
    </ol></li>

<li><a href="#new-high-bit-depth-precision-options">New high bit depth precision options</a>

    <ol>
    <li><a href="#menu-for-choosing-the-image-precision">Menu for choosing the image precision</a></li>
    <li><a href="#which-precision-should-you-choose-for-editing-">Which precision should you choose for editing?</a></li>
    <li><a href="#using-the-image-precision-options-when-exporting-an-image-to-disk">Using the image precision options when exporting an image to disk</a></li>
    </ol></li>

<li><a href="#new-color-management-options">New color management options</a>

    <ol>
    <li><a href="#gimp-2-9-2-automatically-detects-camera-dcf-information">GIMP 2.9.2 automatically detects camera DCF information</a></li>
    <li><a href="#black-point-compensation">Black point compensation</a></li>
    </ol></li>

<li><a href="#new-and-updated-algorithms-for-converting-to-luminance-lab-and-lch">New and updated algorithms for converting to Luminance, LAB, and LCH</a>

    <ol>
    <li><a href="#converting-srgb-images-from-color-to-black-and-white-using-luma-and-luminance">Converting sRGB images from Color to Black and White using Luma and Luminance</a></li>
    <li><a href="#decomposing-from-srgb-to-lab">Decomposing from sRGB to LAB</a></li>
    <li><a href="#lch-the-actually-usable-replacement-for-the-entirely-inadequate-color-space-known-as-hsv-">LCH: the actually usable replacement for the entirely inadequate color space known as “HSV”</a></li>
    </ol></li>

Introduction: high bit depth GIMP 2.9.2

Purpose of this guide

As announced on the GIMP users and developers mailing lists, the recent (November 26, 2015) GIMP 2.9.2 release is the first development release in the GIMP 2.9.x series leading to GIMP 2.10. The release announcement summarizes the many code changes that were made to port the old GIMP code over to GEGL’s high bit depth processing.

Portrait Lighting Cheat Sheets

Thu, 17 Sep 2015 09:23:35 -0500

Many moons ago I had written about acquiring a YN-560 speedlight for playing around with off-camera lighting. At the time I wanted to experiment with how different modifiers might be used in a portrait setting. Unfortunately, these were lighting modifiers that I didn’t own yet.

I wasn’t going to let that slow me down, though!

If you want to skip the how and why to get straight to the cheat sheets, click here .

Softness and Superresolution

Tue, 08 Sep 2015 12:13:08 -0500

A small update on how things are progressing (hint: well!) and some neat things the community is playing with.

I have been quiet these past few weeks because I decided I didn’t have enough to do and thought a rebuild/redesign of the GIMP website would be fun, apparently. Well, it is fun and something that couldn’t hurt to do. So I stepped up to help out.

A Question of Softness

There was a thread recently on a certain large social network in a group dedicated to off-camera flash. The thread was started by someone with the comment:

Freaky Details (Calvin Hollywood)

Mon, 31 Aug 2015 14:33:50 -0500

German photographer/digital artist/photoshop trainer Calvin Hollywood has a rather unique style to his photography. It’s a sort of edgy, gritty, hyper-realistic result, almost a blend between illustration and photography.

As part of one of his courses, he talks about a technique for accentuating details in an image that he calls “Freaky Details”.

Here is Calvin describing this technique using Photoshop:

In my meandering around different retouching tutorials I came across it a while ago, and wanted to replicate the results in GIMP if possible. There were a couple of problems that I ran into for replicating the exact same workflow:

Notes from the dark(table) Side

Fri, 14 Aug 2015 09:32:34 -0500

We recently posted about the Open Source Photography Course from photographer Riley Brandt. We now also have a review of the course as well.

This review is actually by one of the darktable developers, houz ! He had originally posted it on discuss as a topic but I think it deserves a blog post instead. (When a developer from a favorite project speaks up, it’s usually worth listening…)

Here is houz’s review:

The Open Source Photography Course Review

by houz

It seems that there is no topic to discuss The Open Source Photography Course yet so let’s get started.

Color Curves Matching

Tue, 04 Aug 2015 14:10:36 -0500

In my previous post on Color Curves for Toning/Grading , I looked at the basics of what the Curves dialog lets you do in GIMP . I had been meaning to revisit the subject with a little more restraint (the color curve in that post was a little rough and gross, but it was for illustration so I hope it served its purpose).

This time I want to look at the use of curves a little more carefully. You’d be amazed at the subtlety that gentle curves can produce in toning your images. Even small changes in your curves can have quite the impact on your final result. For instance, have a look at the four film emulation curves created by Petteri Sulonen (if you haven’t read his page yet on creating these curves, it’s well worth your time):

New Discuss Categories and Logging In

Thu, 30 Jul 2015 16:56:42 -0500

Hot on the heels of our last post about welcoming G’MIC to the forums at discuss.pixls.us , I thought I should speak briefly about some other additions I’ve recently made.

These were tough for me to finally make a decision about. I want to be careful and not get crazy with over-categorization. At the same time, I do want to make good logical breakdowns for people that is still intuitive.

Here is what the current category breakdown looks like for discuss:

Basic Color Curves

Mon, 27 Jul 2015 10:26:49 -0500

Color has this amazing ability to evoke emotional responses from us. From the warm glow of a sunny summer afternoon to a cool refreshing early evening in fall. We associate colors with certain moods, places, feelings, and memories (consciously or not).

Volumes have been written on color and I am in no ways even remotely qualified to speak on it. So I won’t.

Instead, we are going to take a look at the use of the Curves tool in GIMP . Even though GIMP is used to demonstrate these ideas, the principles are generic to just about any RGB curve adjustments.

Welcome G'MIC

Wed, 22 Jul 2015 16:49:52 -0500

Anyone who’s followed me for a while likely knows that I’m friends with G’MIC (GREYC’s Magic for Image Computing) creator David Tschumperlé . I was also able to release all of my film emulation presets on G’MIC for everyone to use with David’s help and we collaborated on a bunch of different fun processing filters for photographers in G’MIC (split details/wavelet decompose, freaky details , film emulation , mean/median averaging , and more).

[David], by Me (at [LGM2014])

It’s also David that helped me by writing a G’MIC script to mean average images for me when I started making my amalgamations (Thus moving me away from my previous method of using Imagemagick ):

Congratulations

Wed, 22 Jul 2015 13:40:41 -0500

I compiled the list of entries this afternoon across the various social networks and let random.org pick an integer in the domain of all of the entries…

So a big congratulations goes out to:

** Denny Weinmann ** (Facebook , @dennyweinmann , Google+ )
and
** Nathan Haines ** (@nhaines , Google+ )

I’ll be contacting you shortly (assuming you don’t read this announcement here first…)! I will need a valid email address from you both in order to send your download links. You can reach me at pixlsus@pixls.us .

The Open Source Photography Course

Wed, 15 Jul 2015 12:12:35 -0500

Photographer Riley Brandt recently released his Open Source Photography Course . I managed to get a little bit of his time to answer some questions for us about his photography and the course itself. You can read the full interview right here :

A Q&A with Photographer Riley Brandt

As an added bonus just for PIXLS.US readers, he has gifted us a nice surprise!

Did Someone Say Free Stuff?

Riley went above and beyond for us. He has graciously offered us an opportunity for 2 readers to win a free copy of the course (one in an open format like WebM/VP8, and another in a popular format like MP4/H.264)!

A Q&A with Photographer Riley Brandt

Wed, 15 Jul 2015 08:47:30 -0500

Riley Brandt is a full-time photographer (and sometimes videographer) at the University of Calgary . He previously worked for the weekly (Calgary) local magazine Fast Forward Weekly (FFWD) as well as Sophia Models International , and his work has been published in many places from the Wall Street Journal to Der Spiegel (and more ).

He recently announced the availability of The Open Source Photography Course . It’s a full photographic workflow course using only free, open source software that he has spent the last ten months putting together.

darktable on Windows

Mon, 13 Jul 2015 16:54:23 -0500

Due to the heated debate lately, a short foreword:

We do not want to harass, insult or criticize anyone due to his or her choice of operating system. Still, from time to time we encounter comments from people accusing us of ignorance or even disrespect towards Windows users. If any of our statements can be interpreted such, we want to apologize for that – and once more give the full explanation of our lacking Windows support.

PhotoFlow Blended Panorama Tutorial

Tue, 07 Jul 2015 09:29:45 -0500

After quite a bit of back and forth I am quite happy to be able to announce that the latest tutorial is up: A Blended Panorama with PhotoFlow ! This contribution comes from Andrea Ferrero , the creator of a new project: PhotoFlow .

In it, he walks through a process of stitching a panorama together using Hugin and blending multiple exposure options through masking in PhotoFlow (see lede image). The results are quite nice and natural looking!

A Blended Panorama with PhotoFlow

Fri, 26 Jun 2015 11:31:39 -0500

The goal of this tutorial is to show how to create a sort-of-HDR panoramic image using only Free and Open Source tools. To explain my workflow I will use the image below as an example.

This panorama was obtained from the combination of six views, each consisting of three bracketed shots at -1EV, 0EV and +1EV exposure. The three exposures are stitched together with the Hugin suite, and then exposure-blended with enfuse . The PhotoFlow RAW editor is used to prepare the initial images and to finalize the processing of the assembled panorama. The final result of the post-processing is below:

Basic Landscape Exposure Blending with GIMP and G'MIC

Tue, 09 Jun 2015 10:34:49 -0500

Photographer Ian Hex had previously explored the topic of exposure blending with us by using luminosity masks in darktable . For his first video tutorial he’s revisiting the subject entirely in GIMP and G’MIC .

Have a look and let him know what you think in the forum. He’s promised more if he gets a good response from people - so let’s give him some encouragement!

Interesting Usertest and Incoming

Fri, 05 Jun 2015 20:00:37 -0500

I ran across a neat website the other day for getting actual user feedback when viewing your website: UserTesting . They have a free option called peek that records a short (~5 min.) screencast of a user visiting the site and narrating their impressions.

You can imagine this to be quite interesting to someone building a site.

It appears the service asks its testers to answer three specific questions (I am assuming this is for the free service mainly):

A New (Old) Tutorial

Wed, 27 May 2015 13:32:07 -0500

A little while back I had attempted to document a shoot with my friend and model, Mairi. In particular I wanted to capture a start-to-finish workflow for processing a portrait using free software. There are often many tutorials for individual portions of a retouching process but rarely do they get seen in the context of a full workflow.

The results became a two -part post on my blog. For posterity (as well as for those who may have missed it the first time around) I am republishing the second part of the tutorial Postprocessing here.

An Open Source Portrait (Mairi)

Mon, 18 May 2015 12:04:49 -0500

This is an article I had written long ago (originally published in 2013). The material is still quite relevant and the workflow hasn’t really changed, so I am republishing it here for posterity and those that may have missed it the first time around.

The previous post for this article went over the shoot that led to this image.

If you’d like to follow along with the image of Mairi, you can download the files from the links below.

Software and Noise

Mon, 18 May 2015 11:38:01 -0500

I want to take a moment to thank everyone for all of the kind words and support over the past week. A positive response can be a great motivator to help keep the momentum rolling (and everyone really has been super positive)!

Software

The Software page is live with a decent start at a list.

I posted an announcement of the site launch over on reddit and one of the comments (from /u/cb900crdr ) was that it might be helpful to have a list of links to programs. I had originally planned on having a page to list the various projects but removed it just before launch (until I could find some time to gather all the links).

It's Alive!

Thu, 07 May 2015 16:25:16 -0500

Well, here we are. I just checked the first blog post and it was dated August 24^th, 2014. I had probably been working on the back end of the site getting things running for the basic blog setup a few weeks prior to that. It’s almost been a full year since I started working on this idea.

So it is with great pleasure that I can finally say…

Welcome to PIXLS.US !

If you’re just now joining us, let me re-iterate the mission statement for this website.

What's In Your Bag?

Mon, 04 May 2015 09:47:58 -0500

That lede image above is a quick (and dirty) snapshot of my go-to bag for running out the door. I thought it might be fun to take a diversion and talk about gear a little bit. Here’s the full image again:

My gear + bag. Not shown, spare battery and memory cards.

I had decided years ago on going with Micro Four Thirds (MFT) as a camera system because I like to travel light, and wanted options to adapt old lenses. (On a side note, I’m still angry that there is not focus-peaking on the E-M5…)

Back to Writing

Wed, 22 Apr 2015 12:00:15 -0500

I took a bit of a break from writing articles to work on getting the forums up and running. We are almost back to a stable enough point that I want to turn my attention back to writing.

I say almost because there are still a few wonky things that I’d like to work out. There is still a little bit of an issue with the comment embeds from the forum for full-blown articles .

Skin Retouching with Wavelet Decompose

Mon, 20 Apr 2015 11:47:07 -0500

Skin retouching is a delicate art.

Effective skin retouching can feel like a black art.

There have been various methods detailed in the past for ways to “smooth” skin in GIMP . Those methods ranged from disappointing at best to downright ridiculous at worst. The disappointing methods were simply a product of the best methods available at the time. The ridiculous ones seemed to be due to a lack of subtlety.

An Opportunity

Mon, 13 Apr 2015 21:59:55 -0500

I think we are at an interesting time for digital imaging. I came across this graph on Petapixel the other day that showed camera sales from 1947 - 2014:

There was explosive growth driven by the Compact Digital market right around 2000. Likely driven by the advent of those inexpensive compact digital cameras and the ubiquity of home computers. It was relatively cheap to get a decent digital camera and the cost per photo suddenly dropped to a previously unheard of amount (compared to shooting film).

A Forum

Fri, 10 Apr 2015 09:40:44 -0500

After much hard work, that basically consisted of me annoying darix as often as possible, I am glad to say that we finally have a Discourse instance set up! Super Big thank you to darix for all the help!

So What?

What does this mean? For starters, we now have a forum/community in place that we can start building around photography and free software.

A neat side-effect of this forum is that we now also have a way to embed forum threads as comments on posts (only blogposts at the moment - I’ll add them to articles shortly).

All the Articles

Mon, 30 Mar 2015 17:31:36 -0500

I spent a little time struggling conceptually with how I wanted to categorize the different types of content I am planning for this site. As I had previously noted , I was already done with creating a blog post type of content, and had noted that I was working on how to show tutorials and ‘showcase’ types of posts.

Apparently, I had the answer in mind when I created that graphic last month. If you notice the two other types of content I am working on, Tutorials and Showcase, are both listed as types Articles on the graphic.

Deep Links

Tue, 24 Mar 2015 17:17:53 -0500

I tried to find a good funny reference to Jack Handey here but failed. Which might be a good thing given how the reference likely shows my age…

I have been working on various bits of the site as well as finishing up a long-overdue article. I’ve also been giving some thoughts in general about interesting ways to move forward with some ideas which I will bore you all with shortly.

Some Updates

Thu, 26 Feb 2015 16:38:21 -0500

I hate when things take me away for a little while, but won’t make any apologies just yet for having little activity here! It’s mostly a one-man show here at the moment so I do beg for some patience as I build things out and get articles together.

Speaking of building things out…

Site Structure

I have been giving some thought to the general site structure lately. I thought it might be fun to talk about it briefly.

Another Article Done

Wed, 07 Jan 2015 09:30:35 -0500

2015 seems to be getting started nicely!

Just before the holidays Ian Hex sent me his finished tutorial to post, and I just finished editing it. It’s a wonderful look at using Luminosity Masks in darktable for targeted adjustments. (Parametric masks in darktable-speak). You can find the new tutorial here:

PIXLS.US: Luminosity Masks in darktable

On a side note, I had previously written about doing [Luminosity Masks in GIMP](http://blog.patdavid.net/2013/11/getting-around-in-gimp-luminosity-masks.html) on my personal blog, and yes I will be porting that tutorial here a little later!

Luminosity Masking in darktable

Tue, 06 Jan 2015 13:41:08 -0500

Luminosity Masking, the ability to create selections of your image based on its specific tones for ultra-targeted editing, is a relatively recent concept favoured by landscape photographers the world over. In this article, we will explore how to create and use Luminosity Masks in the F/OSS RAW editor darktable , so that you can make adjustments on your RAW files to isolated tones.

What is Luminosity Masking?

Luminosity Masking is a technique developed in the last 10 years or so primarily by American Southwest landscape photographer Tony Kuyper over at goodlight.us . Tony provides extensive writing and information on Luminosity Masking and how to create Luminosity Masks; in this article I’ll be primarily focusing and creating and using the masks in darktable, but if you want to really understand the basics I highly recommend giving Tony’s guide a good read over first.

Still Writing

Thu, 11 Dec 2014 21:15:16 -0500

It’s been a busy month (+ ½) for me personally. Things have finally settled down so I can get back to writing articles and working on the site.

Wavelets Coming

As I mentioned in the previous post , I’m currently working through a re-write of the various tutorials I had done about using Wavelet Decompose for skin retouching. I’m about ²⁄₃ of the way through it now and expect to have it finished shortly.

Iterating

Tue, 28 Oct 2014 21:59:05 -0500

I’m working my way through some of the suggestions I’ve received from many folks. In particular, the “px” icon in the upper left to slide open the navigation and Table of Contents has been changed to a (hopefully) more familiar ‘hamburger’ icon. I’ll also be testing some other things in the coming weeks as time permits such as having a TOC show up by default in the right ⅓ of the page at the top.

Getting Closer

Thu, 25 Sep 2014 17:18:12 -0500

Just a quick update on a couple of interesting things.

The first article is almost done being re-written and updated.

I added some functionality to the slide-out menu and am still thinking about the best icon to use.

I also had a nice epiphany when I realized that the styling I had already written to make big videos works great for images as well.

Digital B&W Conversion (GIMP)

Tue, 16 Sep 2014 13:36:26 -0500

Black and White photography is a big topic that deserves entire books devoted to the subject. In this article we are going to explore some of the most common methods for converting a color digital image into monochrome in GIMP .

What We are Trying to Achieve

There are a few things you should focus on in regards to preparing your images for a B&W conversion. You want to keep in mind that by removing color information you are effectively left with only tonal data (and composition) to convey your intentions.

Commenting

Mon, 15 Sep 2014 16:30:22 -0500

First things first. I forgot to actually link to the new About page in my last post. So here it is . As with all things related to the site, any feedback, comments, or criticisms are welcome!

Speaking of feedback, comments, and criticisms, I wanted to write about it for a moment.

First, I want to thank everyone who has taken the time to contact me and provide me feedback on the site. You have no idea how valuable it is to both as a motivator, and as a means to know when something is off. I appreciate and give my full attention to each and every person and idea thrown at me. Thank you!

An About Page and Help

Sat, 13 Sep 2014 21:36:18 -0500

I’ve started working a bit on the “About” page for the site. I wanted a place to highlight the mission statement I’m sort of working from:

To provide tutorials, workflows and a showcase for high-quality photography using Free/Open Source Software.

As well as a place to let users know who is behind the scenes working on the site. It’s mostly me at the moment, but I’ve managed to talk someone into helping me…

The Big Picture

Mon, 08 Sep 2014 11:06:28 -0500

Sometimes I get into weird OCD mode where I need to have something for better or worse. One of those things was a desire to break out of the mold of standard blog-type posts in articles for this site. I’ve sometimes found images are relegated to second-class citizens on some page layouts that don’t do them justice.

I couldn’t let that happen here. The problem was that I needed to do some things to make sure the typographic layouts were visually strong as well. This meant a adding control to width and layout of main text elements, with the downside of having to hack a bit to make images large.

RSS Feed & Social Media

Thu, 04 Sep 2014 10:15:33 -0500

It took a bit of digging and wrestling to get there, but a couple of nights ago I also managed to get an RSS feed working for the blog posts on the site. Honestly, I spent more time fiddling with dates in javascript than I should have.

I had to make some minor modifications this morning to accommodate where the location should be, but it should be live now.

The location is: http://pixls.us/blog/feed.xml .

Both the blog index pages and post pages contain a <link> element that point to it, so most readers should find the feed if you point it at a page. I’ll test it later, but the most important thing is the location is correct regardless of whatever hacking I do to the feed itself later.

A Push Menu

Wed, 03 Sep 2014 12:17:16 -0500

So, I’ve had the idea in my head for a while that it would be nice to get the navigation out of the way. When I’m reading an article or tutorial, I don’t want to be inundated with elements that aren’t pertinent to what I’m reading. I want to focus on the content.

On Building PIXLS.US

Tue, 02 Sep 2014 09:35:51 -0500

For the curious, and to serve as an introduction, I thought I’d make a few notes about how this site is built and what I’m currently obsessing over. Hopefully this can help define what I’m up to in case anyone wants to jump in and help out.

The Purpose

The entire point of this site, its “mission statement” if you will, is:

To provide tutorials, workflows and a showcase for high-quality photography using Free/Open Source Software.

Subject to revisions, of course, but mostly sums up what I’d like to accomplish here. I also think it’s good to have this documented somewhere to remind me. :)

Hello World!

Sun, 24 Aug 2014 19:40:00 -0500

Well, technically this isn’t the first post on the site. I had actually started with building out the temporary Coming Soon page. Then I shifted focus on styling the main content page for the site (articles). After a bit I realized that I should probably be working on some sort of blog posts as a means for folks to keep up with what I’m doing.

So, here we are!

Who Am I?

I’m Pat David .

Yes, I need a new headshot.

I’m an occasional photographer and I dabble in digital artwork occasionally as the mood strikes me. I also happen to be a fan of free software. Those two worlds collide fairly often, and lately I’ve been having a great time writing about them.

I’ve been writing tutorials on my blog as well as trying to modernize/update tutorials on the GIMP website . You could call me a (small) part of the GIMP team (but I’m trying to do more!). I also try to help out where I can on other F/OSS projects as well (G’MIC is another place you’ll find me bumming around). I do these things because I think it’s important to try and give back to the community in whatever way you’re capable of.

I’m loud. So I figured I could use that capability to help out.

(It’s my demented super-power).

Building PIXLS.US

Mon, 01 Jan 0001 00:00:00 +0000

This is just a log of reference material for actually building this site. It’s mostly for my own reference and edification. If you’re reading this, good luck making sense of my notes…

Static Website with Node.js and Metalsmith

I decided to build this site as a static website. This means that I’m generating all of the material on my local machines, and then compiling them into static webpages that are then uploaded to the server for serving. While this does sound like a pain in the ass, there are static site generators that make this job much easier.

From PIXLS with Love ❤️

Mon, 01 Jan 0001 00:00:00 +0000

PIXLS.US is a passion project.

We ❤️ the Free Software projects and all of the dedicated creators and users that make this such an amazing community! Part of what we want to do is help spread the word about these awesome projects.

We also try to help by providing these projects with resources such as website design, hosting, and providing them communities in the forums . Some of the projects we love and work closely with include:

Software

Mon, 01 Jan 0001 00:00:00 +0000