Printing and colour management

[Rimsky]

Hi all

It's a while since I've been on the forum - so hi everyone!

I bought my Canon 40D in Jan '08 and have been snapping away with varying results! I have finally got round to looking at RAW files and manipulating them within Photoshop's CameraRaw application. I also did a bit of reading up on the best colour space to use when creating a Jpeg and I reckoned that PhotoPro RGB offered the kind of gamut I was after.

Once I had done lots of tweaking of levels, curves, white balance, saturation etc. I created 8-bit Jpegs and took them to Jessops to get printed (as I do not have the kit or patience to do it myself).

The results were quite a shock. The colours are very different to those viewed on my (calibrated) screen and very unnatural. Before I take these prints back to Jessops and complain, this is the understanding I have of the situation. Perhaps someone could verify my logic!

As I have enabled colour management in Photoshop, the colour space information should be embedded in the Jpegs I provided. Therefore, Jessops should pick up on this information and print accordingly. If they are unable to handle PhotoPro RGB then they should have contacted me rather than go ahead and make the prints.

Is my technical knowledge of colour spaces and management sound? I'd be grateful for any help.

Many thanks,
Mark

[Bob Andersson]

Hi Rimsky,

I think you might find that you'll have to convert the colour space down to sRGB before submitting for printing. Hopefully Jessops will provide some detail on what they expect on a web-page somewhere - it's quite possible that they expect a particular colour space and don't check the actual one used. I think only the very top tier of labs will support PhotoPro RGB.

Bob.

[keystrokesuk]

Some web pages that discuss similar issues:

http://duramecho.com/Photography/Photog ... index.html
http://www.techmind.org/photoprinting/index.html
http://photo.net/digital-darkroom-forum/00TMHF

If you can get Jessops to tell you or send you the colour profile of their printer then you should be able to get a better match.

[Rimsky]

Thanks for your replies. I went to Jessops and explained (complained!) and they tried reprinting some of the shots to check whether it was a just a one-off glitch. The prints were just as bad (if not worse in some cases). So I got a refund.

I think Jessops really isn't the best place for me to get prints done as they're not knowledgable enough about colour spaces, ICC profiles and the like. They didn't seem to understand that the files I gave them included embedded colour profile information which would be useful (essential) for them to reproduce prints as I viewed them on my screen.

I'm sure that this has been covered before on these forums but can anybody recommend a good, knowledgable printing lab? Or redirect me to a thread on the topic.

I understand that I may have to convert my Jpegs to sRGB. I'm not a Photoshop wizz (yet). Is there a function within CS4 to convert a batch of Jpegs from one space to another?

Many thanks again for all the help given on this forum.

Mark

[capital]

I think that most consumer oriented places will have sRGB as the "assumed" working space.

I also think you made a slightly big mistake directly converting from your file in 16 bit ProPhotoRGB to a 8 bit JPEG in ProPhotoRGB. ProPhotoRGB color space is so big, you actually need 16 Bits of resolution to sufficiently contain it, so converting to 8 bit you can potentially posterize your image.

What'd be better is to do a profile conversion to sRGB and then convert to 8 bit JPEG. The object of this is to maintain as much precision as possible through all your image editing procedures before finalizing at a lower bit depth, this rule of thumb is good to follow with most image editing.

To convert from your ProPhotoRGB to sRGB, goto the menu option under:

Edit > Convert to Profile...

and select sRGB IEC61966-2.1

To batch convert to another working space in PS4 you can use the Image Processor and couple it with an Action.

Image processor is found under:

File > Scripts > Image Processor...

and under preferences, add the Action you've made that does a conversion of profile.

Google or Search online or Youtube search how to create an Action, it will be far better explained than having me rehashing something better shown in a video, or graphically illustrated guide.

[Rimsky]

Brilliant. Many thanks for the advice.