LR's color workspace is fixed to ProPhotoRGB and there is no SoftProofing ability. However, the image should look the same in every truly color managed application like LR. It's a must that your scrren has to be calibrated correctly for this to work.
When you export an image you do apply a color space in the export dialog and you can choose between ProPhotoRGB, AdobeRGB and sRGB depending on what you are planning to do with the exported image.
Can you explain to me how to change Lightroom's working colour space for on-screen viewing?
You can't and you really don't want to...
First off, Lightroom doesn't use Pro Photo RGB as it's internal color space...it uses the color coordinates of Pro Photo RGB but a linear gamma. This is done to maintain ALL of the colors your camera can capture and process in a linear gamma like your camera. This is the internal processing pipeline and you will NEVER be allowed to alter that pipeline...
You can indeed export in one of three color spaces but Lightroom 3 will allow the selection of another RGB profile beyond those three...(can't remember if LR 2.x can do this). You can't export to Lab or CMYK.
OK guys, thank you for your response; your manner is fantastic. However I'm very disappointed that Adobe excluded soft-proofing in dif
ferent colour-spaces from Lightroom2, especially when Photoshop has it. Lightroom 2 was advertised as designed by photographers for
photograghers. I'm new to digital photography & perhaps attribute unneccasary value to this omitted facility, otherwise its exclusio
n must surely be so that it may be included at a later date and a higher cost. But thanks for your help. My only further enquiry is
what the best route may be for getting my RAW files in Ltrm to look as good (the same as) they do in sRGB in my Canon DPP software w
hich doesn't use ProPhotoRGB:- I have a calibrated screen & use the Adobe Canon 20D Camera profile. All the colours are rendered cru
dely & unconvincingly and Ltrm loses the finer sense of light, texture space and authentic colour/tonal relationships. I've manually
adjusted the camera calibration settings myself with inconsistent results. I now intend to buy an expensive colour checker chart, t
ake a photo of it using my camera and run a script in ACR or create a DNG Profile to produce camera profile compensation values to i
nput into Ltrm. Do you know of any simpler or more obvious solution I just don't know of which may make Ltrm render my photos as wel
l as my sRGB Canon software does or atleast with more accuracy and believability. This issue has been incredibly disappointing for m
e as Adobe are known as the industry standard manufacturers. To date it prevents me switching fully from Canon software to Ltrm & I'
d very much like too! I realise this may be a very technical enquiry but I really want to sort this out and appreciate any assistanc
e. Thanks for your time!
What did you use to calibrate your screen?
LR shows you its own, Adobes interpretation of how the data in your RAW files should look. It will never look exactly as it does with a Canon software. If you don't like it, you have to make your own preset.
Regarding Soft Proofing: It's on the 'wishlist' of most of the LR users since day 1 and Adobe does know that. However, we dont know more about their plans. You may want to add a thread here http://forums.adobe.com/community/lightroom/lightroom_feature_requests to support the wish.