John Stovall writes …
why would I not won’t to use ProPhoto as my default color space since it’s a larger space and provides more "Head Room" than does Adobe RGB (1998).
Two main reasons … 1) you can’t actually see the full extent of this space (which encompasses all visible light, much wider than the gamut of almost any image you’ll actually capture) on any monitor you can actually afford, so editing is very hit or miss and 2) you can’t use these extra colors (ie, colors beyond the gamut of say ARGB) because no output device can print or display them (with a couple of exceptions).
I was following the work flow suggested in
"Real World Camera Raw with Photoshop CS2: Industrial-Strength Production Techniques" by Bruce Frazer.
Are you SURE he said to use ProPhoto as your main working space? I really doubt this … like many others on this NG I respect Bruce’s work a great deal but he’s been pretty consistent over the years in saying that you should use the ultra-wide working spaces sparingly. For example, in his book "Real World Camera Raw with Adobe Photoshop CS" he suggests checking the RAW histogram to see if you have out of gamut colors and if so switch to a wider space (like ProPhoto), "then use Convert to Profile to convert the images into your working space of choice". (pg 70-71)
If you’re really worried about clipping colors in saturated images then I’d suggest trying a tool like Chromix’s Color Think, which lets you plot the actual gamut of an image against a profile (working space or printer or monitor or whatever type of profile). If you find you are clipping a lot of colors then you can use a wider space on those type of images at conversion and then convert to profile further in the flow. That’s what I do, using either Ektaspace (gamut of color slide film) or, rarely, ProPhoto (gamut of visible light) for maybe 2-3% of my images, then converting to something easier to work with, typically AdobeRGB. Here’s a sample of the image linked to below, the dots are the gamut of the image, the smooth area the gamut of a printer profile, showing how and where this rendering of the image is out of gamut for this paper profile.
http://members.aol.com/bhilton665/CT_demo.jpg You can convert the RAW files multiple times and compare results … for example, this abstract shot has some saturated colors with smooth gradients and I find I get better final prints (less blocky colors, better smoothness in the gradients) when converted using Ektaspace … here’s a screen dump showing some test conversions in the File Browser, where I’ve converted it from the RAW with several different working spaces, then converted again to a printer profile …
http://members.aol.com/bhilton665/tulips.jpg … try this on some of your shots and see if you really need to use ProPhoto RGB all the time.
In brief, the wide gamut working spaces are useful when you need them (highly saturated colors) but require care and most of the time you don’t need them. I wouldn’t want to use one as my main default working space. Here’s an early (PS 6 era) article by Fraser which essentially says the same thing …
http://www.creativepro.com/story/feature/8582.html?origin=st ory Bill