I see in your signature that you have been designing medical cameras since 1976 so I'd like to better understand where you are coming from with your advice as most of us don't design cameras.
I have questions about some aspects of your posts as from my understanding of things you are starting from false premises. "If the capture was in "camera color space" and it was converted to sRGB choosing either relative colorimetric or perceptual, then all the colors in the scene will be moved into the color space selected. There will be no clipping of colors. The colors may not represent the scene exactly ... "
The colors in a scene exist independently from the limitations of the sensor, processor and processing algorithms used in a camera, and also from the artificial constraints of any RGB, LAB, XYZ, etc. color space all of which are synthetically derived from mathematical models of human perception. Colors can exist in a scene that exist outside of the limitations but also it is possible for a camera to capture and a color space to contain colors and tone differences that even the healthiest of unaided human visual systems (Camera eye and visual cortex - AKA "naked eye") cannot see. A simple example of this is the rendering of the blend of evanescent colors recorded during a very long exposure."...but the colors will be represented within the color space. "
Not if you choose a color space, like sRGB that is smaller than the gamut of colors present in the scene. The colors in the scene that are outside of the color spaces gamut are automatically clamped (Joseph Holmes' term) to the limits of the color space. Equally important their relationship to colors that do fit into your chosen color space's gamut are distorted. (the architecture of the color space may also distort these naked eye perceived color relationships."If you want to maintain the closest relationship between the scene and the image using absolute colorimetric, then you must convert the camera data from RAW into a color space big enough to hold all the colors. For many people this is Adobe 1998. But that is only done for product shots (absolute colorimetric, I mean.)"
I do not know enough about using the Absolute Colorimetric rendering intent to comment. I do a fair amount of actual product and people photography , as well as warchitectural and lanatural world work. The vast majority of man made products fit nicely into Adobe RGB(1998) if not sRGB. The main problems I have with small (sRGB) and relatively large (Adobe RGB(1998)) color spaces clamping colors are outdoor scenes.
"The histogram only shows colors that are available to it - which is the monitor color space usually close to sRGB - so no matter how much you stare at it you aren't going to see any colors beyond the small sRGB color space of your monitor, which hopefully is calibrated."
Others have answered you on this but only partially. Which histogram are you referring to: the one you see on a camera or the one you are using in a raw processing program (Adobe Camera Raw, Aperture, Bibble, CaptureOne, Lightroom, etc.) or post-processing program (Photoshop, etc.)? If the camera, the histogram is determined by how you have set the camera up to do the raw to JPEG processing: primarily the color space setting, but also white balance, contrast, and the various "camera styles" settings.
If you are referring to the histogram in Adobe Camera Raw or in Photoshop your statement is only true if you have chosen your display's profile to work within. While Lightroom primarily uses Adobe Camera Raw as the processing engine in the develop module , the histogram is based on what has been nicknamed "Melissa RGB" a variant of ProPhoto RGB with a TRC (Tone Response Curve) AKA "Gamma" of 2.2 as opposed to 1.8 as used in ProPhoto RGB. My understanding from both verbal and email interviews and communications with various Lightroom team members is that this was done to make it a better fit to the naked eye. "If you start with Adobe 1998 color space, the CMS converts it into monitor color space by the conversion method you have chosen (perceptual, relative colorimetric or absolute colorimetric.) "
This is only true of the version of the document (photograph) that is sent to the display. "If you don't choose absolute colorimetric then no color data is clipped, only changed to fit what the monitor is able to show - that is good greens and blues and not so good reds and yellows."
Again I must pass on the discussion of the Absolute Colorimetric rendering intent. As to what colorss the display is capable of displaying - that depends specifically of the characteristics of the display being discussed and also the settings you have used to calibrate it to and the device and software you are using to profile it with.
"Remember all you see is a representation of the colors that the monitor can produce, not what the printer can print."
That is absolutely true. The display and printer (really the specific combination of printer, ink (if ink is used) and paper) are two different devices. If you are printing the real proof is the print."Digital cameras don't have to deal with such a wide range of color - except in product shots in the studio, so sRGB is usually okay as a capture color space."
In my experience and also according to Joe Holmes (http://www.josephholmes.com/propages/AboutRGBSpaces.html
) that is absolutely untrue.
I do not suffer from the illusion that my knowledge is infinite, especially regarding the science of color and how our photographic and reprographic devices render it , and am always looking to expand what I know. If you can help me in that process I am grateful.