Adobe RGB or sRGB setting on Canon 40D (which to use)

Thank you Andrew for your prompt and confirming answer.. That's about what I thought but I will now preserve the color space instead of converting it.

Andrew is an acknowledged expert in this area (he has written books about it). You may also find the following helpful:

 

http://www.cambridgeincolour.com/tutorials/color-management1.htm

 

http://www.cambridgeincolour.com/tutorials/sRGB-AdobeRGB1998.htm

Thanks for clearing this up Andrew! It's good to have a resident expert here!

 

Just one point. On the cameras that have it, Highlight Tone Priority also affects the RAW file as well as exposure and ISO. Though Canon haven't given exact details of how HTP works, it's presumably done through a variable gain hardware step that acts much like the gain associated with the ISO setting, except that the gain for HTP is non-linear, with highlights getting less gain than shadows and therefore being more resistant to "blowing out". It's done in hardware before the A/D conversion required to generate the RAW data.

This is actually part of the problem I was having in lightroom... whenever I exported a jpg (sRGB) it looked like crap (lost all color and saturation)

 

I fixed this by exporting in the right color space. Interesting stuff.

It's probably best to use the sRGB setting. Although the camera's color space doesn't matter to the raw converter, it could matter to any software that uses the medium-resolution JPEG embedded in the raw file to create thumbnails or previews. That includes stand-alone hard disk devices that can display images on an LCD screen or a TV set (they can't decode the actual raw file, but they can display the embedded JPEG). Those thumbnails or previews will look more accurate if they're written in sRGB, since the software or device probably isn't aware of color spaces. An Adobe RGB JPEG will probably look washed out.

 

For what it's worth, I set my Rebel XT to increased saturation, contrast, and sharpness (and sRGB). Adobe Camera Raw ignores all those settings (although Canon's raw converters will use them). But the images on the camera's LCD display or a hotel TV screen look better because they're actually the embedded JPEGs in the raw files.

Wow! Great information here. Thanks to everyone for giving me a crash course education in color space. I appreciate the time you spent helping me out. My wife and I caught an earlier flight to Alaska. Heading to the airport in an hour or so. Thanks for all the info on RGB settings. With some luck, I hope to capture some memorable shots. The info offered here will certainly help. Thank you!

Hey Ted that's a good point! I have one of those backup devices that reads the jpeg data within the raw file. And if it really doesn't make a difference when shooting raw, then I might switch.

In short the best setting to use if space and format afforded is ProPhoto RGB as it maintains the most followed by Adobe RGB 1998 than sRGB.

 

http://www.luminous-landscape.com/tutorials/prophoto-rgb.shtml

I suggest Albert reads the links I provided - the largest colour space won't always give you the best result.

Not to negate your post Mark but I question the source as it has no citations. Moreover, logic says 16bit is better than 8bit. Furthermore, printer vs. monitor comparison should be considered. Lastly, even your expert Andrew has suggested ProPhoto RGB.

 

Correct me if I'm wrong. I'm not claiming to be an expert but logic suggest this.

It's funny, I started reading this thread knowing what to do and then everybody chirps in :)

 

Seriously, I shoot in ARGB and print in it, if I put it on the web then i convert it to SRGB, if you don't do that you'll find that the photo will appear ot be a bit hazy or cloudy, don't know why but I'll bet somebody here does.

IF you shoot Raw, and output to a modern ink jet (or expect to print to some device in

the future yet on the market), you'd be well advised to stick with 16-bit ProPhoto as an

encoding space for master rendered images, especially if you're using Lightroom or

ACR.

 

The reasons are explained here:

http://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf

 

Adobe RGB isn't a wide enough gamut to contain the possible gamut of a scene or the

capture device most are using.

 

While there are way more colors that can be defined in something like ProPhoto RGB

than you could possibly capture, we have to live with a disconnect between the simple

shapes of RGB working space and the vastly more complex shapes of output color

spaces to the point we're trying to fit round pegs in square holes. To do this, you need a

much larger square hole. Simple matrix profiles of RGB working spaces when plotted 3

dimensionally illustrate that they reach their maximum saturation at high luminance

levels. The opposite is seen with print (output) color spaces. Printers produce color by

adding ink or some colorant, working space profiles are based on building more

saturation by adding more light due to the differences in subtractive and additive color

models. To counter this, you need a really big RGB working space like ProPhoto RGB

again due to the simple size and to fit the round peg in the bigger square hole. Their

shapes are simple and predictable. Then there is the issue of very dark colors of

intense saturation which do occur in nature and we can capture with many devices.

Many of these colors fall outside Adobe RGB (1998) and when you encode into such a

space, you clip the colors to the degree that smooth gradations become solid blobs in

print, again due to the dissimilar shapes and differences in how the two spaces relate to

luminance.

All the authorities seem to agree - shoot in RAW. The RAW downloaders (at least Lightroom) defaults to Prophoto RGB which is the largest color gamut and which allows for most accurate adjustment. The other RGB's are important only afterward - sRGB designed for monitor display, Adobe RGB for printing.

Everything Peter Su said, especially:

 

"IMHO if you are asking this question you should be using sRGB. If you can articulate a reason to use some other color space, then go ahead."

 

I might have missed it - but has Dan (the OP) said what he intends to do with his images?

>The other RGB's are important only afterward - sRGB designed for monitor display,

Adobe RGB for printing.

 

Minor but important point. Nether is designed for these tasks, both are based on a

theoretical emissive display output devices defined using three simple attributes (TRC

gamma, white point and chromaticity values for RGB). There were designed as Quasi-

Device Independent editing spaces with differing gamuts (just like ColorMatch RGB,

ProPhoto RGB etc).

Andrew Rodney. I printed out and studied the reference you posted above. I now get what you have been talking about. I now, for the first time, understand what I am trying to manage by using different color spaces. It was well written, the visual are great and the article now sits by my computer for reference, I recommend it to anyone who would like to understand the subject better. BTW I think your name would be a great one for a detective in a british mystery. Apologies to Agatha.

This thread demonstrates one of the key problems of these forums -

misunderstandings can be stated as truths, leading to further misunderstandings

which become conventional wisdom. (1D Mk III issues spring to mind)

 

This is not an issue of "different schools of thought" or opinion - it's a simple

unequivocal fact - embedded color spaces make no difference to the image content

of a RAW file, none.

 

As Colin correctly states, it changes to prefix on the naming of the file and puts a

tag in the metadata, that's it. The colorspace decision is made at the output stage

and can be previewed in the RAW processor.

This one may can help