I was wondering why Adobe didn’t include its Melissa RGB as an export/output space?
I can see a number of possible advantages for doing so:
- When editing images afterwards in Photoshop, users will see exactly the same histogram and RGB numbers under the cursor as they did in Lightroom.
- Theoretically, edits in Photoshop, that expects gamma encoded input, are applied perceptually more uniform in a working space with a 2.2 gamma than in a 1.8 gamma space like ProPhoto RGB.
I'm aware that the TRC in sRGB and Melissa RGB isn’t EXACTLY a gamma of 2.2 because the exponent in the equation is 2.4, but they use an offset that results in a tone response curve that is very similar to gamma 2.2, with a little advantage in the shadows though.
- Raw files encoded in Melissa RGB with its sRGB tone response curve could supply some extra room in the shadows.
Anyway, I'm somewhat intrigued by this Melissa thing and I created my own Melissa RGB working space for testing/experimenting (it uses sRGB's 1024 multipoint Tone Response Curve and the primaries/whitepoint of ProPhotoRGB). If you're interested in a copy for experimenting, just PM your email address.
Herman
