![]() ![]() Make sure you generate LAB cLUT type of ICC profile, but not a basic simplified Matrix type of ICC profile. Film negative scans start to look and feels like slightly mixed with some slide film colors. Custom made input ICC profile always makes things magically look better. (this is known problem with with digital cameras but i didn't test this in real life with film scans) Digital sensors are sensitive to IR light and so final images may have brownish-magenta tint that may affect RGB AutoLevels and so may produce incorrect color. Halogen lamps combined with 80A filters may work, but produce huge amount of IR pollution. Also for best possible color in single click you need:ĥ500K-6500 high CRI LEDs should be OK. Manual calibration also helps a lot to fix problems with low quality LED backlight sources.Ĥ. This step is more-less optional for DSLR cameras because in most cases developers provide more-less ok input profiles for them. To create custom Input ICC profile use IT 8.7 Scanner Calibration Target like these Affordable IT 8.7 (ISO 12641) Scanner Color Calibration Targets and use Rough Profiler app to generate Lab cLUT based ICC profile. Optionally you need to Calibrate your camera or scanner. Also in sRGB gamma Auto Levels may produce very different result if applied before or after Invert.ĭon't forget to convert final image from L* gamma to sRGB gamma for final 8 bit web delivery.ģ. Working gamma affects a lot highlights rolloff look and so film scans inverted in sRGB gamma start to look "too digital". This cause huge shifts in tonality and require aggressive manual curve adjustments with too many non-technical "guesses" and "fixes". Most free as well as commercial tools usually do Invert in basic sRGB tonal curve. ![]() To generate working ICC profiles with L* gamma use Synthetic ICC app from Displa圜AL-Display Calibration and Characterization powered by ArgyllCMS package, or use RawTherapee ICC Profile Creator, or just use Elle Stone's Well-Behaved ICC Profiles (L* named there as labl) ellelstone/elles_icc_profiles. Do invert and per channel RGB AutoLevels in L*gamma working profile. I described this problem in details here negadoctor invert mistake Ģ. Those filters may slightly amplify blue channel, but they also will change original ratio between colors. Same goes to Blue filters applied after WB was set. Colors will shift a lot depending of Color Space and Gamma you use. When you start to adjust WB in RAW or attempt to pick orange mask in RAW, this cause shift in input profile and colors became incorrect after Invert. You may notice that this is the first essential task that every real scanner do when you turn it on. White balance camera to your light source and don't change WB anymore in RAW file. In short workflow looks like this:ĭebayer RAW file and convert it from Camera input ICC profile to ProPhotoRGB with L* gamma custom-made ICC profile -> Invert -> Apply RGB AutoLevels -> Recover back clipped data from RGB AutoLevels -> Adjust tonal curve and Contrast.ġ. This workflow works with Linear Tiff files from Film Scanners as well as with DSLR reproduction systems. I start to investigate film negative scanning questions about 10 years ago and currently develop some really fast but same time technically correct workflow. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |