There is no way to manipulate the image within ACR to fit it into a printer profile color space, only into one of the four provided workspaces. One is flying blind trying to edit the image in ACR for a final print rendering. I edited the image at a point in the workfllow where I could more accurately judge print color gamut fit, and by using ProPhoto I didn't "throw away" any colors in advance.
If the end goal is for email/web, i.e. display only, then I agree manipulating within ACR in sRGB is ok, and that's exactly what I do for 95% of my pictures, saving directly out of ACR.
Thanks, Richard. That's been very helpful to me. I'm glad I brought it up.
Most of my profile conversions were from ProPhoto to Adobe, or ProPhoto to sRGB. Occasionally, I would print using an Epson 1400 A3+ inkjet, using a variety of supplied and home-made profiles, and have to prove the conversion in Photoshop.
I was under the misapprehension that profile conversions were supposed to do the whole job of making the image work in a different colour space, with the rendering intent chosen to give the best conversion. In effect, I've learned that this isn't the case, and that adjustments need to be made before the conversion.
I recently adopted the use of a AdobeRGB workspace in ACR because I supply stock photography in this colour space, and I find ACR's controls to be easy to use and intuitive. Plus, further conversions to sRGB for digital frame, projector, and web within Photoshop have produced perfectly acceptable results 99% of the time. By processing within the constraints of AdobeRGB, I am able to simplify and streamline 95% of my efforts.
By using ProPhoto, I would have to work with Photoshops adjustment tools, which I find less intuitive (and subsequently slower), and would result in the collection of many PSDs containing processed raw files with adjustment layers. To be honest, I prefer the simplicity and small size of the humble XMP sidecar file.
However, I now understand that this isn't the best way to work if a decent print is the goal. Photoshop is the only part of the workflow where the image can be properly shoe-horned into a printer profile, and this must be done with the application of adjustment layers! Clink (the sound of a penny dropping)!
[edited because the sound of a dropping penny is apparently offensive]
I don't believe you have to be in ProPhoto to always obtain a "decent print", and if I were you I wouldn't change the present workflow, since it suits your needs well. The particular example you provided is relatively extreme, in that it's clipped in both sRGB and Adobe1998, and the only way to get it into Photoshop "untouched" is via ProPhoto. This won't be the case with most images with Adobe1998 as the chosen space - if there is no clipping in ACR there is no reason to go to ProPhoto. Just keep an eye out for images such as the one you provided.
The red channel seems to be the main culprit causing clipping, I run into it often taking pictures of bright yellow flowers, of which there are an abundance in my neighborhood. Very few are suitable for printing, so most of them get the ACR treatment to tame them down before saving out for display viewing, in sRGB. So again back to the original theme of this thread, I wish I had a clean way to switch between the two. Banging back and forth between two config files works, but it's a little scary in that it's outside the control of ACR, and I'm not sure I won't eventually be bitten.
Ah, thanks for the clarification. For some reason it hadn't crossed my mind that it might be tied to my preferred working space, but now it makes sense.
One wonders, if the tool is capable of producing output in whatever color space you have configured, why not keep the image's original color space? Maybe when they tried that it was popping up messages for people who configured profile mismatch warnings.