Prophoto RGB

[francois]

...If you assign a processing parameter like Adobe RGB in the camera, is this overridden by your raw converter? ...

You are correct! The space set in your camera is not used by converters like Adobe Camera Raw, Capture One or Bibble.

... In the section 'Prophoto RGB in use' Michael talks about tagging the output file with the camera's profile (in C1 pro), I wasn't sure if this meant the assigned profile (Adobe RGB for example) or a generic Rebel profile?  ...

In Capture One you will be using your "Generic Rebel Profile" or a custom profile like those from Etc... When you open the file in Photoshop - depending on your color settings - you will be asked to convert it to ProPhoto (provided ProPhoto is your working color space).

In Adobe Camera Raw, you only have the choice of sRGB, ColorMatch, AdobeRGB and ProPhoto (maybe some others, my memory sometimes fails) as output profiles.

Not sure if I have addressed your questions, though?

Francois

[Richowens]

Hi hovis
I can only reply with my own experience using Prophoto rgb.
I use a d70 with the color space set to Adobe rgb, but with the working space set to Prophoto in Nikon Capture.
In my experience and from my understanding of Michael's article the raw convertor will disregard the setting in the camera and apply the working space to the file.
I had a shot of a sunset that I just could not get excited over using Adobe rgb as the working color space. It looked good, but not quite as I remembered it.
After reading Michael's article, I reprocessed it with Prophoto as the working space. Now it sings to me. The colors are more subtle in gradations, and the lone cloud has that slight touch of pink I could not get with Adobe rgb.
I hope this helps with your question.

Rich

[francois]

... You might want to read this as well (it’s not geeky):
http://www.color.org/ICC_whi....ics.pdf ...

Thanks for the pointer.
 ::

Francois

[hovis]

I've just read Michael's article 'Understanding Prophoto RGB' and have a question.

If you assign a processing parameter like Adobe RGB in the camera, is this overridden by your raw converter? I have a Rebel which has only two processing parameters available, sRGB and Adobe RGB, are these profiles merely temporary solutions so that the camera can process an image but do not affect the true gamut of what the sensor is picking up?

In the section 'Prophoto RGB in use' Michael talks about tagging the output file with the camera's profile (in C1 pro), I wasn't sure if this meant the assigned profile (Adobe RGB for example) or a generic Rebel profile? Either way I don't understand how this will convert to the wider gamut of Prophoto RGB.

[TeddyLoves]

If you assign a processing parameter like Adobe RGB in the camera, is this overridden by your raw converter? I have a Rebel which has only two processing parameters available, sRGB and Adobe RGB, are these profiles merely temporary solutions so that the camera can process an image but do not affect the true gamut of what the sensor is picking up?

you are right. but those spaces are not quite "overridden" by raw converter. when you shoot in raw, your camera has its own color space, which will be converted into either sRGB, Adobe RGB, Color Match RGB, or Prophoto RGB in ACR, or some other RGB spaces in other raw converters. the sRGB and ARGB color spaces in your camera are used to process captured data into JPG if you shoot in JPG. if you dont shoot in JPG, this option doesn't matter.

[digitaldog]

It’s useful when discussing RAW to color conversions (or on the fly conversions in camera) to understand the differences between rendering color and encoding the color. Rendering is the process whereby the RAW data is turned into a full color image to appear as the user wishes (or based on the manufacturer if done in camera). When you set your camera to do this internally, you have no control and this is done based on how the manufacturer thinks they are producing the most pleasing color. This is like how Kodak feels Ektachrome should render a scene versus how Fuji feels Velvia should render the scene. Neither is “correct” (certainly not colorimetrically correct meaning the measured color in the scene).

Encoding is then taking that color rendering and putting it into a color space (sRGB, Adobe RGB (1998) and so on). This is not at all ambiguous. The same encoding or scene data into sRGB is used if you have a Nikon, a Canon etc. The Rendering isn’t!

You might want to read this as well (it’s not geeky):
http://www.color.org/ICC_whi....ics.pdf

[hovis]

So if I set C1 Pro to 'convert to destination' and the working space in Photoshop to Prophoto RGB there will be no loss of colour gamut from the raw file?