[JAG]

I use Lightroom for around 95% of any post processing I do. I don’t own a printer as I send any images I want printing off to Photobox. My question is this. I use the SRGB colour space as most of the images I consider good enough I will publish to my website or the Pixalo Gallery etc.. What colour space should I be using to export for printing or is it ok to leave it as SRGB? I’ve tried getting my head round colour spaces but to be honest, the whole subject fries my brain.

Many thanks,

Ian

[silkstone]

Controversy time again!

I use sRGB for everything, and neither I nor anyone else has ever complained. The main advantage of sRGB is that it is suitable for everything and keeps things simple. People run into problems using Adobe RGB (aRGB) colorspace and then trying to display on the web or in an application that isn't colorspace-aware without converting the image to sRGB first. The colours will look wrong.

The drawback of sRGB is that its gamut is not quite as wide as aRGB - although the differences are not as great as is sometimes made out. It means that some intense colours - especially strong magentas and cyans - are contained in aRGB but not sRGB. However, most monitors will not display beyond the sRGB range, so you won't see these extra colours unless you print on a printer that can reproduce beyond sRGB.

Another benefit of sRGB, apart from simplicity, is that there is a smaller increment between each gradation of colour, so blocking or posterisation is less likely to occur in 8-bit images.

Having said all that, I am (yet again ) in a minority, and most 'serious' photographers tend to use aRGB. However, if you shoot in RAW, you can always go back and re-process to whatever colorspace you like, using the same edits.

And finally... many internet and high-street print shops want sRGB anyway.

[Larne]

I use Adobe RGB for printing and sRGB for web. I actually do everything in Adobe RGB and then convert to sRGB for web use if I need to (unless I forget which happens a lot). I have been playing with Lightroom and I find that its ProPhoto RGB really messes up the colours on my Pixma iP4500 so I am sticking with Adobe RGB which works perfectly.

[VinnyP]

The answer is not straightforwards. For Photobox they use 2 different processes; they use sRGB for small prints and for posters they use whatever profile you embed. For the former you will get better results if you submit sRGB. For the latter the larger profiles will give better results. But the choice with Lightroom (Or most other raw converters) is not limited to sRGB or aRGB there is a third much better way.

If you are working in 8 bit then sRGB or aRGB will not make so much of a difference. In general there is no disadvantage (except for file size and slight performance loss) in always working in a 16 bit lossless format like Tiff or PSD then converting down to whatever you need.

As for colour space as Silkstone says aRGB has more colours but some low end monitors can't display them all and some printers can't print them all. sRGB has narrower gradations between it's fewer colours so your budget monitors and printers will actually get more out of sRGB. Converting from aRGB to sRGB will lose some colour info and converting up to aRGB will effectively give you the same colour range with coarser graduations. This used to be the constant debate before ......

The answer is ProPhotoRGB (Lightroom and Prophoto poster printing support this). This has the best of both worlds it's effectively sRGB with aRGB and a little bit more besides. So if you ever need to convert to sRGB or aRGB you will be fine.

On Photobox you can download their printer profiles they have a Polielectronica Laserlab which has a much different profile to sRGB and has many colours that sRGB can't handle indeed it has few dark reds and purples that are outside aRGB

It's a bit like preparing images for the web. It's always better to work with the large file and then resize as needed rather than trying to work with the resized file (except of course for sharpening)

[silkstone]

See what you've done Ian? So far... one vote for sRGB, one for Adobe RGB and one for ProPhotoRGB.

It's perhaps worth reiterating that RAW files do not have any colorspace - it doesn't matter what the camera is set to - the colorspace is embedded when you convert the file to JPEG, TIFF or whatever.

[VinnyP]

Originally Posted by silkstone

It's perhaps worth reiterating that RAW files do not have any colorspace - it doesn't matter what the camera is set to - the colorspace is embedded when you convert the file to JPEG, TIFF or whatever.

Indeed a RAW file has a wider colour gamut than any of the colour spaces.

[JAG]

Wow! I told you it fried my brain!

Thank you all so much for taking the time and explaining the differences in a way I can understand. I think the best thing for me to do is have a play and get the same image processed and printed using the mentioned methods and see if I can notice any differences and make my choices.

Ian

[silkstone]

Good idea Ian. What matters is the finished product, and there may be more than one way of getting a good result.

[Dave Canon]

I use Adobe RGB (1998) for my archived images as I print myself. My source files are RAW and I edit in 16 bits. However, I do produce versions for digital projection and the web bit it is so simple to convert using the Image Processor in CS3, I just convert to sRGB, resize and save as JPEG as required.

However, for you, it seems to me that sRGB would be the best option for the web and Photobox. I do not know if you edit in 16 bits but, if you do not, that is another reason why you may be better to stick to sRGB.

I did some tests recently and though I can see a diiference in the output from my printer between Adobe RGB(1998) and sRGB (cyans and green better on Adobe RGB) when printing a test chart, it is very difficult to see any difference in real photographs but this may a limitation of my printer.