Profiling a camera with darktable-chart

On bash, Windows and ^M, see also IM with Cygwin: Line ends. That was written for Cygwin bash, and Microsoft bash may have relevant differences.

@snibgo @ggbutcher@paperdigits Thanks guys it was my use of notepad to edit the scriptā€¦When I just cloned the project to a folder and ran the script it ran. I now want to modify it so I will do so in the terminal to avoid any further issuesā€¦Thanks. My first attempt was just a quick shot of the target in my basement to get a file to work with so it was too dark and the resulting icc way over brightens the imageā€¦I will do a proper evaluation and comment if I think the results are worth mention. I had never seen anyone comment on using this script beforeā€¦Thanks for your help as I might have been chasing my tail or given up before the simple fixā€¦

Iā€™ll add that on my system (Cygwin on Windows 8.1), ā€œ/usr/binā€ and ā€œ/binā€ are the same place. I donā€™t know if that is generally true of Unix systems, or Cygwin on Windows, or other bashes on Windows, or what.

Usually theyā€™re not the same place on a *nix system. /bin is usually root/sudo programs, while /use/bin is accessible by regular users. Since cygwin is a regular user application, it makes sense that theyā€™re the same.

Historically, as pointed out by @paperdigits, they are separated. Although most Linux systems follow it, nowadays this deviation from the FHS (Filesystem Hierarchy Standard) is seen more and more on Linux (and alike) systems.

For example on my Debian box /bin and /usr/bin are also symlinked.

Hi guys, I have no problem with the jpg file and this style produces images equal to the in camera jpg.
Instead I canā€™t reproduce the real colors with .cie reference file (or base data reference already present in DT-chartā€¦ i have a leading red. Some ideas?

how did you solve this problem? simply by replacing ā€œcolumnā€ with ā€œidā€?
I did this but I donā€™t think thatā€™s enough, the results are still bad:
https://redmine.darktable.org/issues/12270
read at the bottomā€¦
here it says it works badly with cie files but work well with jpg reference and it8, and this is what I see tooā€¦
I just buyed the C1 target from Wolf Faust (coloraid.de) with its it8 reference file, we hope it worksā€¦

@asn I just canā€™t create my real color styleā€¦ :sob:
I was able to reply in camera jpg but not real color; i have a wolf faust it8 color chart but at the end of tutorial color is not real, in fact are very bad.
Can you help me please?

@Nikoh can you provide more details?

Hi guys, some step forwardā€¦ the problem is daylight temperature. Iā€™ve always shot in the morning but here https://www.cambridgeincolour.com/tutorials/sunrise-sunset-calculator.htm I realized that the morning is not good.
Now i want to measure light temperature with the custom wb and a neutral 18% gray card (colorchecker passport) over the day; it is hard because my olympus e-m1 markii does not allow to see immediately the custom wb value, so I will have to calibrate and shoot throughout the day and then see the data in darktable. in this way I will know at what time I will have the right temperature of 5000k and next day I will be able to shot the color chart in that moment.
the mistake I made was to always shoot during the morning when the color temperature is quite below 5000k, so the result I had had a yellow / red castā€¦

Also if you have glare you can forget the shots ā€¦

Hello everyone, i am trying to profile my camera but iā€™m having problemsā€¦
Wolf Faust (coloraid.de) sent me a C1 color chart with reference files.

  1. I shot (raw+jpg) several photos during a whole sunny day in August,
    without clouds.
  2. After i used wb spot calibration on mid gray box (L=50 a=0 b=0 less or more) to know about light temperature for
    each photo and I discovered I had the right light around nine in the
    morning (more or less).
  3. I chose the photo that had the best exposure so the raw whose the jpg
    value of the lightest box equal to the reference value written in the file
    sent with the color chart, in my case GS00 L = 90, to have the right curve.
  4. I exported raw file in lab and pfm float
  5. i load that image as a source on darktable-chart
  6. i load cht file it8 standard file to have a right grid
  7. i chose cie file as a reference and i chose the cie file sent from wolf
    faust and NOW start the problemsā€¦
    For first, reference file is like GS0, GS1 etc. and dt-chart need something
    like GS00, GS01; ok i edit the file manually and now dt-chart load the file
    without problems.

After, the values that i can see on the bottom, in the L (reference) column
are differents from those that i can see opening the file with a text
editor, e.g. GS23 on file is l=4 but i can see that dt-chart give me GS23
l=0,00 and likewise other values; I donā€™t know if this is normal but I
think not, please someone can confirm or not :wink:

Maybe you can install Argyll and use their cie/cht filesā€¦for your IT8

already done, same thingā€¦

Your chart image needs to have absolutely no clipped values in the patches. Iā€™d rather underexpose a bit than clipā€¦ I use different software, but the measurement protocol is the same.

Please can you can read my problem before replyā€¦

I did, no evidence you had considered this.

Stupid question does orientation matterā€¦I had to rotate my image for DT chart or it didnā€™t work??

You might also want to take a look here ā€¦this is a slightly different approachā€¦using your jpg and raw to create a icc fileā€¦uses argyll in the back groundā€¦it is linux script but I have modified it for my color chart and run it on the linux kernel in windowsā€¦I need to run a few more pairs through it in different lighting but it might be another approach GitHub - pmjdebruijn/colormatch: ColorMatch

There is some documentation about CIE files in argyll. Iā€™ve just read that and modified the files from X-Rite accordingly so they work. I guess you have to do the same from Wolf. Maybe we should upload those here.