How to create Adobe Camera RAW Profile from IT8 and DSLR?

Discussion in 'Digital Darkroom' started by pavelkupcik, Jan 3, 2021.

  1. I have been scanning film slides using Nikon Coolscan V calibrated with IT8 film slide targets (Velvia 50, 100, Provia 100) from Wolf Faust. I have also started digitizing film slides with DSLR camera on a copy stand and light table. Would you have any advice on a good workflow to profile raw files from digital camera using IT8 slides. Do you know of any way to create Adobe Camera RAW profiles that I could then directly assign to raw photo in ACR? For regular digital photos (not film reproduction) I have used successfully Color Checker Camera Calibration which can create a custom ACR profile from my Color Checker passport, but it does not allow the use of 3rd party film targets. I’m looking for a similar concept but one that works with film IT8 targets and hopefully allows me to stay in RAW workflow instead of intermediate TIFF files.

    If there’s not a way to create ACR profile, what would be the best next alternative? Take a photo, assign a neutral camera profile in ACR, export to TIFF and then profile as usual? I also own Color Perfect photoshop plugin for negatives – would the MakeTiff utility from that software help in any way to create linear TIFF from camera RAW file and then create a profile from that TIFF, in a similar way I produce profiles from Vuescan RAW TIFF with Nikon film scanner - see workflow below?

    My current method for profiling flatbed and film scanners is: Create RAW TIFF in Vuescan, open it in Photoshop, do not assign color profile, use levels to assign gamma (anywhere between 2.2-3.5), export to TIFF, run it through Rough Profiler, repeat cycle with different gamma assigned in PS to find result with lowest max and average error, check that black and white do not clip. E.g. for Velvia 100 on Nikon Coolscan V, my best results are with Vuescan master analog gain set to 1.5 and photoshop assigned levels gamma at 3.0.

    Thank you.
     
  2. Btw, I also looked at the DNG Profile Editor from Adobe, but it supports only one target: 24 patch ColorChecker chart. It has no way of using other targets/charts.
     
  3. The genuine Kodak IT8 targets had a corresponding published dataset that gave x,y,z coordinates for each patch on each particular issue of slide.

    It should be possible to create a convolution to translate those coordinates into another space. That's if they still exist online somewhere.
     
  4. X-Rite software that comes with a calibrator can analyze several charts and come up with a camera profile. You can use that profile when you open the image file in Photoshop or Lightroom, and render the RAW file in a standard color space.
     
  5. This looks very promising, just need to find few hours to read through all the info. Thank you for the tip.
     
  6. Which specific software and calibrator are you referring to? I have i1Display with HW dongle to calibrate monitors, that won't help. I have ColorChecker Passport, but that doesn't allow calibrating with 3rd party IT8 targets. I see that Xrite has this: https://www.xrite.com/categories/ca...ssic-family/colorchecker-i1-scanner-profiling but it can only take a TIFF file as input and not a camera RAW (DNG) file.

    I'm looking for something that can analyze DNG file and produce DNG profile that can be assigned in ACR or Lightroom.

    I looked through the xrite website, but can't see anything that would help. Can you please point me to it. Thank you.
     
  7. I have an i1 Display (emissive), i1 Studio (reflective and emissive) and an obsolete i1 Pro.

    X-Rite software has various features which are selectively unlocked by connecting the hardware device to the computer by USB. The i1 Studio is the most versatile, capable of both emissive and reflectance measurements (monitors, projectors and printers). The i1 Studio also unlocks camera and scanner calibration tools which read several types of X-Rite patch charts.
     
  8. I've been reading the Lumariver documentation. It looks like excellent software for my purpose. If anyone used it, can you please share your experience with it for profiling cameras and scanners. Thank you.
     
  9. I went with the Profile Designer Pro Edition since I'm not yet interested with reproduction profiles. The documentation is really excellent, just read through most if you can and then maybe try the demo. You can make a profile for your camera and edit it till the cows come home too.
     

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