In the past I have used Adobe RGB. My calibrated and profiled monitor produced prints I am happy with. When posing to my web site, I did not change to sRGB, but left them as is and changed them to low Res JPGs. They look fine on my web site. Now my questions:
I am readinf Jeff Schewe 's Digital Negative book, which highly recommends using Prophoto RGB for prints. I am switching to that color space. But he also says this color space is not good for web use, and recommends sRGB. I am not sure how to make a small jpg copy, and change its color space. If I reduce in size a COPY of the Prophotob RGB image the use SAVE FOR WEB, will that change color space and work OK? Next question: I want to have a press printed, bound large coffee table book made. What color space should I use, and how do I change it in Photoshop?
Dave......still homeless on NJ coast after Sandy
Sorry to hear that you are homeless after Sandy, and hope things work out for you shortly.
If you use Lightroom, you don't have to worry about color space until you export, since the image is not actually rendered into a color space until that time. The internal working space in LR (and ACR) is ProPhoto primaries with a linear tone curve.The readouts and histograms in LR are in Mellisa, which uses the same primaries but an sRGB tone curve. ACR lets you choose among several color spaces and the histograms and readouts are in that space. When one prints from Lightroom it is not necessary to render into ProPhotoRGB and one can send the image directly to the printer rendered into a printer profile from which on can use rendering intents.
Much of the web is not color managed, but if you have a select audience, you can use files tagged with AdobeRGB or ProPhotoRGB and tell your audience to use a color managed browser (such as Firefox or Safari. The latest version of Internet Explorer is also color managed. See this ICC post
. Otherwise, you should use sRGB for the web. If you save to the web in PS or export for the web in LR, out of gamut colors will be clipped, since perceptual rendering is not available (it is listed in Photoshop, but the setting is ignored). If you image has no out of gamut colors, things will be OK.
If you would like to try perceptual rendering, you might check out Ver 4 sRGB. See the ICC site
and read White Paper 26 in the link. The color gurus do not seem to discuss Ver 4 other than to say that it is not ready for prime time.