How many times must we point out that Mellisa is not the working space in ACR/LR. Mellisa has ProPhoto primaries and an sRGB TRC and is used to compute the color readouts and histograms. The working space is unnamed and uses ProPhoto primaries and a linear TRC.
I use ACR/LR for most of my work and agree that one should render into 16 bit ProPhotoRGB with ACR rather than trying to fit the gamut of the image into the working space (usually sRGB, Adobe RGB, or ProphotoRGB). With LR the image stays in the linear space until printing or export and, short of soft proofing, there is no good way to determine if the editing parameters place the image in the gamut of sRGB or AdobeRGB. It is true that editing may result in color that can not bee seen on the monitor or printed with available printers, but LR does have a monitor gamut warning and the Digitaldog has pointed out that if saturation adjustments produce no visible change on the monitor, one has exceeded the gamut of the monitor. Later on, you may get a better printer or monitor, so why limit your options?
Bill
If you do most of your color adjustments in Lightroom then you can always go back to your raw file and do whatever tweaks you want at any time, so you won't be limiting your options and will be able to make full use of your new monitor or printer.
If you don't want to lose your Photoshop adjustments then you can use a smart object, which means you can render into any working space or output space you want, whenever you want.
I agree that if you are working in 16-bit that the choice of working space is less critical, but the wrong working space can potentially result in clipping or posterisation. I'm sure you've all seen this tutorial (and Bill, I know you know all this already (and I am not being sarcastic)), but it is nevertheless a very clear and useful summary of the issues:
Cambridge In Color sRGB v ARGB.
At any rate, what color space you use is entirely up to you, of course. But I remember not so very long ago thinking that ProPhoto had to be better because it was larger and that Lab was even better because it was much larger still, not having a clue that I was doing all sorts of horrible things to my image.
So I think that it's a good discipline to ask oneself, before rendering an image to a color space, or converting to another color space, what the destination of this particular variant of the image is and whether or not the image gamut will fit into the intended space. For example, if the destination is going to be the web and we ask ourselves this question, then we will almost automatically do a soft-proof with gamut-warning to check that it does fit and we will be sensitive to the color shifts and clipping that may occur on the conversion if it doesn't fit (and find ways to make these less intrusive). If we do not ask ourselves the question then we are more likely to blindly convert and forget or not realize that we may end up with a poorer result than we could have done.
Of course it depends on one's workflow. In my case I will (now that I understand the issues a bit better) make the decision: web or printer, in Lightroom. If I can't then I will wait until I know what I want to do with the image, or I'll use a smart object. I think that the processing of the image is very dependent on the destination. For example, noise reduction and output sharpening will not be the same for a small web image as for a very large print on a wide-gamut printer. Other things are common, for example the bulk of tonal and color adjustments, deblur, geometric distortion, chromatic aberration correction etc. Which strongly suggests (to me) that these should be done in the raw converter if at all possible.
The Lightroom virtual copy feature is particularly nice for this because we can have a variant for each intended destination very easily. The bulk of the adjustments can be made on the master and then we can have a virtual copy for the web and one for print and we can make the final tweaks there while keeping our master intact. Then, if at a later stage we get a wonderful new printer with a much larger gamut ... well we can just make another virtual copy or modify our print virtual copy.
Which really goes back to my original topic question (which was, by the way, triggered by an article by Michael Reichmann who said "The major steps which I take in Capture One are to choose the appropriate camera profile, do a white balance, and then set black point and white point.
These are the critical steps that need to be done in raw mode (
my bolding). I then export the file to Lightroom for further processing. I send the file as a 16 bit TIFF. "). So I wondered if he was right or not ... and based on our discussion here I wouldn't say that he was wrong, exactly, but then again I don't think he was right either. These probably
are the essential steps, but they are certainly not the only steps that would benefit (in some cases significantly) from being done pre-rendering to TIFF. Of course the choice of profile for the TIFF is itself an essential choice to be made prior to render (unless one uses C1 and chooses (unwisely IMO) to use the camera profile).
So for me it's still going to be sRGB first, Adobe RGB second, Beta RGB third ... depending on the image and the destination ... and then if I absolutely need it, ProPhoto RGB (or perhaps the printer profile if I know precisely what the printer and paper are going to be). I know that the digitaldog vehemently disagrees with this ... but it's a free country fortunately, so each of us can do what he wills
Robert