sRGB and Adobe 1998 Colour Settings Question

First, my apologies if this has been covered before.

I use a couple of Canon bodies, shoot in RAW and use DPP 3.5 and Photoshop CS3 Extended.

My understanding of the sRGB and Adobe 1998 colour gamut settings is that sRGB (having a narrower colour gamut) is better for web/screen display, sending files to be printed at Walmart, etc., and also using an in home printer (I have a ip4300 and an i9900), while Adobe RGB (which has a wider colour gamut) is better when using higher end printing services or more refined at home printing devices.

If this is not right please correct me.

My photos and post processing of other photographers's images is intended in some cases for uses more suited for sRGB (as I understand it) and in other cases more suited for Adobe 1998.

I currently have both my bodies set to operate in sRGB, and I also have Photoshop and DPP also set as using sRGB colour space.

So here are my questions:

1) Can I leave my camera bodies operating in sRGB, take photos, and then during processing with DPP or Photoshop make the change to Adobe 1998 if I want to use the wider colour gamut for a particular image?

2) Does the RAW image taken by the camera differ if the body is set for sRGB or Adobe 1998, or is this difference just reflected in the parameters being passed along to the post processing application?

3) At what stage of post proceessing should one make the switch to Adobe 1998 from sRGB, if that switch is indeed possible? I usually do all I can in DPP and if necessary send a converted TIF to CS3 for further editing.

Thanks in advance to all the experts for answering my questions ...

Maxdave

Maxdave wrote in post #7410002
I currently have both my bodies set to operate in sRGB, and I also have Photoshop and DPP also set as using sRGB colour space.

So here are my questions:

1) Can I leave my camera bodies operating in sRGB, take photos, and then during processing with DPP or Photoshop make the change to Adobe 1998 if I want to use the wider colour gamut for a particular image?

2) Does the RAW image taken by the camera differ if the body is set for sRGB or Adobe 1998, or is this difference just reflected in the parameters being passed along to the post processing application?

3) At what stage of post proceessing should one make the switch to Adobe 1998 from sRGB, if that switch is indeed possible? I usually do all I can in DPP and if necessary send a converted TIF to CS3 for further editing.

I'll take a shot at answering... Color management gurus, feel free to smack me down at any time!

1. If you're shooting ONLY in RAW, it doesn't matter what color space you have your cameras set to, sRGB or Adobe RGB 1998. If you shoot JPGs at all and will be working in the Adobe RGB color space at all, you need to have your camera set to Adobe RGB color space. sRGB captures a smaller gamut of colors and tones than Adobe RGB so you would not be capturing as much color information.

2. Follows from question one and you have an accurate understanding of the issue. The RAW image is independent of the color space set on your camera and represents all the unprocessed image information captured by the camera's sensor.

3. Here's where you need clarification. Going from sRGB to Adobe RGB is like trying to make a box of 24 crayons into a box of 64. You should start post processing within the Adobe RGB color space and save your Tifs or PSDs as Adobe RGB. You can always create an sRGB JPG image from the saved Tif later, depending on your needs.

Bottom line is: Don't try to go from a small gamut to a larger gamut.

Thanks, Chas ....

(actually, I am asking this question far in advance, I intend to visit your state for eight weeks starting in late August, and want my photos to reflect what is best of your location!)

Maxdave

3) Probably as late as possible. I leave all destructive conversions until the last minute... ie convert to profile (sRGB), save as jpg.

It's only with RGB>CMYK that you have to sometimes juggle when you need to convert, and then for intent, it's not that important... more often it's needed when you need to adjust specific CMYK values, and PS"s tools limit you to RGB adjustments.

Maxdave... Look me up if you're ever near Albuquerque and I'll show you some New Mex hospitality!

Most has already been said, but I have a few things to add:

AdobeRGB is also the better choice when printing to an inkjet printer, such as your ip4300 and i9900. Both will exceed sRGB, and even AdobeRGB, in some colors.

On the conversion: If images aren't printed, I'd probably use sRGB from the beginning. Makes little difference, but in ACR you get a clipping warning for the color space used, so it's easier to prevent clipping that way.

When converting from AdobeRGB to sRGB, all out of gamut colors will be clipped, since it's a colorimetric conversion by definition.
Converting from sRGB to AdobeRGB makes very little sense to me; you gain nothing in the process.

When you shoot raw, it makes no difference if you set sRGB or AdobeRGB in the camera. It does however influence the preview and histogram (as do all camera parameters)

Have a read in the link from my sig.

Does anyone what should use if I normally upload to website like photobox.co.uk
and let them print it out and send it off to me?

Now I use sRGB....will Adobe RGB better in colors?

Thanks

unless a printer has been setup to use aRGB, your prints will come back looking dull

the majority of online print companies use sRGB

aRGB is usually used in the print industry where converting to CMYK, it gives the best results

As others have already mentioned, there's no need to set any color space on the camera when shooting RAW.

I prefer to use ProPhoto RGB as my color space when editing images in Photoshop. ProPhoto RGB has a color gamut even larger than Adobe RGB and gives me additional headroom when editing images. I convert to sRGB or Adobe RGB when necessary, but try to stay in ProPhoto RGB as long as possible.

This is completely analogous to using 16-bit versus 8-bit bit depths. Sure, printers and (most) LCD screens are 8-bit devices, but using 16-bit bit depth results in less loss of dynamic range during the editing process.

?? I think dynamic range is dictated by the colour space, not bit depth.

But your point is sound. There are advantages to using high-bit files, especially if you're (a) working in very large colour spaces; or (b) a lousy photographer whose images need major tonal adjustments in Photoshop.

I'd say dynamic range has nothing to do with either bit depth or color space.
It's simply a characteristic of the camera used...

On a side note: "larger" doesn't equal "better" for a color space.
Theoretically, the best color space to use is the smallest that will contain all the colors in the subject and both camera and output gamut...

Thanks mate, I was clearly out of my depth there.

Is the black-to-white tonal range exactly the same in all colour spaces, though? I thought there might be some difference.

0 to 255.
A larger gamut color space has more saturated colors, not brighter or darker AFAIK.
Then again, I don't know what would be the case for imaginary colors. That's why I rarely use L*ab

Deepest black is determined by the ink, brightest white = no ink, so is determined by the paper.