Luminous Landscape Forum

Raw & Post Processing, Printing => Adobe Lightroom Q&A => Topic started by: Hermie on February 25, 2007, 11:30:05 am

Title: Melissa RGB
Post by: Hermie on February 25, 2007, 11:30:05 am
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
Title: Melissa RGB
Post by: seanmcfoto on February 25, 2007, 01:00:51 pm
Quote
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
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In Podcast 8 they say there's enough color spaces out there already..