Still not got my head around ICC profiles!

Swatcher

Swatcher

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Edit My Images
No
Thought I had but...

I have an EOS 500D set to sRGB, taking RAW, which I process in DPP on a PC that uses a custom ICC created and set by the monitor calibration software. In the preferences I therefore have the default work colour space set to sRGB too. So far so good, I think.

Also in DPP Preferences is a section for "Colour matching settings". The display sub-section can be set to sRGB, OS (currently set) or I can browse to set one of the many provided, including the custom ICC for the monitor. This makes a big difference to how the pictures look on screen - sRGB makes them look more saturated - but I'm working on the assumption that I should use the OS setting so that images look the same in DPP and Windows.

It's what happens to the resultant jpegs that is making me scratch my head. Some of these will be going into the world as digital images and will therefore be seen on monitors that run different profile to mine, probably sRGB.

Should I export using the OS settings for those I display on my monitor and sRGB for those I intend to distribute more widely? Or should I make sure the "Embed ICC profile in image" option is un-ticked in the Export dialog and so let each system decide, so people will see my images in a colour space they are seeing everything else in?

Some images will be going to high-street printers. Same again, i.e. don't attach a profile, let them do it at their end?

Hope you understand what I'm talking about.

Regards,
Swatcher

PS: There is a possible complication in that many images were edited on an entirely sRGB system, before I got my posh monitor.
 
As far as I understand it :)

The profile is a lookup table that converts numbers to colours and vice-versa. So in adobeRGB (100,10,10) might point to a richer red than the same numbers in sRGB.

Most monitors can show (something like) sRGB whereas commercial printers may be able to show a greater colour range, including bits of AdobeRGB.

For showing pics on screen, I think it's accurate to use "OS (currently set)" in DPP. Then DPP knows what the monitor + OS is doing and can compensate appropriately. The aim is that your monitor looks like your prints will, not that it looks good. So if it looks washed out on the monitor it should be safe to increase saturation / contrast etc., knowing your prints won't be radioactive.

You could even take pictures in adobeRGB. DPP should be able to convert them to sRGB. That way you'll have a record of the richer colours in the scene should you ever want to go back and process again for high quality printing.

If you don't know where images will be seen, I think it's best to export using sRGB and include the profile too. Profile-aware browsers (eg firefox, maybe with it turned on in options) should read the profile, but even those that don't will hopefully be just about right. High-street printers may expect sRGB by default. Alternatively DSCL and others have profiles for their printers + papers on their website you can download and export with. Hopefully this lets you get the richest possible colours that they can do.
 
Thanks, Parsley. Do you know which profile is attached during export? The "Default settings of Work colour space" or "Colour matching settings for display"? When I export one with and one without, both look the same on both monitors I have access to.
 
Sorry I don't. I normally use photoshop - only tried DPP yesterday as it came with the 550D :) I've just bought.

I _think_ most software assumes sRGB if it's not specified.

I've just tried opening DPP files in photoshop, and from 2 tests so far DPP saves files in the "Default settings of work colour space" profile, not what you pick in "for display" or "printing profile". Or you can change it per image in "Adjustment / work colour space..."

I think that if you choose sRGB, you'll be missing out on the chance of slightly richer colours on a few systems with wide gamut monitors and correct settings which can interpret them, but everyone will see what you do. If you choose AdobeRGB you'll get slightly washed-out colours on most systems that don't have correct settings / profile-aware software, but a few folks will see them properly. I don't know if any high-street or internet printers will correctly honour an attached profile, so you might be best off with sRGB for them too (or their own profile, but DPP doesn't seem to support this for file export, only direct printing).

hope this helps
 
Yes, it does, thanks. I think I'll get onto my monitor supplier (seeing as it's their profile that's muddying the waters, I think! - and is probably irrelevant in this specific issue) and I suppose the printers will have been asked this once or twice too... Your advice on the pros and cons of exporting with sRGB make sense and chimes with what I've heard elsewhere.

Thanks again,
Swatcher
 
No probs. Having the monitor profile is good though - it lets your monitor properly show how the image will appear when printed, as long as it's printed correctly.

Each device needs a profile - a look up table from numbers to colours - and then DPP makes sure that wherever your image goes, it is shown correctly. Unfortunately it won't let you re-encode an image to use the profile for some arbitrary internet printer, but otherwise it's ok.
 
Is your monitor calibrated? No matter how "posh" it is, what they look like on your screen will likely be wrong unless the monitor is calibrated - colours will just not be accurate! As soon as you edit in DPP on an uncalibratred device - bang - your colours will start to be off.

Also do you do a custom white balance when shooting? Another place that colour can be interpreted wrongly by your camera - nop matter the colour space. You caqn change in RAW easily but unless your monitor is calibrated you are leaving it to open to error.

There's a lot to colour management you've not even mentioned here like browsers - which can show images differently too.
 
Yes, it is calibrated and regularly, using ColorNavigator and an x-rite i1. But this isn't the profile I would export with the jpeg, is it? In fact, it's not even an option in the work colour space.

I'm beginning to see a "colour-flow" from camera to printer. It doesn't go via the monitor, the monitor just has a window onto it and needs the right glasses for the job. How good's that for an analogy?

I have the DSCL profiles. At what point do I use them?

Hello again, EOS_JD! I knew it was only a matter of time.
 
Swatcher, I think you are getting the idea.

Shooting RAW the image file has no colour space. It's simply a set of numbers relating to how the imaging chip saw the image. Now the processing software will put it into a kind of limbo colour space to work on it. DPP will do it one way Adobe may do it another, but in essence the images at this stage has no real colour space assigned to it.

Now the monitor profile is important as it takes he characteristics of the monitor and applies them to the viewed image. It makes not changes to the actual files . Your spectacles analogy is a good one.

Now once you've adjusted your image in the RAW converter it's time to get it into the real world. It is at this point that you need to tell the converter what colourspace the file needs to be rendered in. When in doubt use sRGB.

Yes there can be problems with people viewing you images in different monitors, all with completely different set ups. It is a problem but nothing you can do about it. sRGB is the best option.

As far as the DSCL profiles are concerned I'd suggest you check with their web site as I believe you use the "Convert to Profile" option in Photoshop and use this as the destination profile. But do check first
 
Thank you, Chappers. In that case it would always be advisable to export the profile, even though it is the "standard" sRGB? I'll speak to the printshop about what they want, it's probably a bit specific.

:bang: The pain also goes away when the lights go on.
 
Hello again Swatcher :) Been a while :)

Also remember that sRGB is the smallest of the gamuts of the common colour spaces.

Do not convert to your monitor's ICC. Use sRGB or aRGB or ProFoto RGB (the largest gamut). If you print in-house aRGB pr ProfotoRGB are fine. If you put on the web sRGB profile is the best.

If you send to a lab, they will tell you what they want.
 
The monitor calibration is separate and is loaded by your OS at start up & if you are using EyeOne then it takes care of the OS calling up the correct ICC profile from your calibration.

Your editing software should be set up as EOS JD has said although many suggest you should use sRGB as this is usually the best your monitor & output printer can achieve. Others say use ProfotoRGB for future proofing. I have to admit I play safe & use ProfotoRGB. The OS will take care of the monitor & your assigned profile. For Web sRGB should be assigned as your output.

For printer proofing you need a printer ICC and in PS you can (& best) to set up the custom setting in VIEW-PROOF SETUP and set for your printer profile & if you are using a print house ask or down load their printer ICC. Hopefully what you see then will match what you get. This will also save in your file to the printhouse
 
Okay, I think I've got a very comprehensive set of answers that I actually understand. Must be getting somwehere...

Many thanks to all contributors.

Swatcher
 
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