Accurate color reproduction

[pcasciola]

I've been noticing that a lot of my post processed shots come back from the photo lab not even close to matching what I see on my display, especially with some deep blues and red hues. So I just invested in a Spyder 2 Pro and calibrated my monitor last night. It does seems somewhat better, but still different, so I think I need to figure out the correct way to use the various ICC profiles. My print shop provided me with the profiles to match the paper he uses (Agfa Laser III) but I am unclear as to when I should apply this profile. If I shoot RAW aRGB, should I convert to the Agfa profile immediately after converting the RAW and before doing any other edits that might affect the color balance?

Also, I purchased the PrintFix scanner with the Spyder 2 which will help me calibrate my own printers, but I'm wondering if this device can also be used to scan in prints done by the photo lab to tweak the profiles he provided me with? Or, should I just send him a Pantone Chart or GretagMacbeth Color Checker Chart to print and tweak my monitor profile to match that?

[foxbat]

I find that the default "CMYK" photoshop proof is way off what comes back from a digital printer. I always switch to "Monitor RGB" (Ctrl-Y) for accurate proofing. Mine has also been Spyder calibrated. Photoshop often switches back to CMYK proofing so you have to keep watching it...

[lancea]

Hi Philip. You say you "shoot RAW aRGB", but the RAW files don't have a colour space till you assign it during conversion. The RAW converter might say it's reading in an sRGB or aRGB file, but it's just reading the tag on the file while is only effective for JPEGs. Anyway, use Adobe RGB for your PS editing. The printer profile is assigned only when want to print the file (or save it for the lab).

[chtgrubbs]

If you are using a professional lab they should be able to supply you with a profile you can use. If you are using a consumer lab then go to http://www.drycreekphoto.com and see if they have a profile you can use. They also have excellent instructions on how to use a profile. They will even create a profil for you if you want. I am not sure how well Printfix will work for this, but it's worth a try.

[pcasciola]

I guess what I should have said is that I am shooting RAW and converting to aRGB/16-bit because I cannot choose a custom profile in ACR. I then immediately convert to the color profile that the photo lab supplied me with, and I get a little closer to the actual output now that the monitor is calibrated, but the dark blues still seem off.

I tried switching the proofing to Monitor RGB, and then the blues are way off compared to CMYK.

I'm going to try uploading the PSDs to see if there is any difference. I had previously been converting everything to 8-bit sRGB JPEG before uploading, which is probably another huge mistake but seems like the only logical choice when uploading 30-40 shots which could be 2Gb in PSDs or TIFs.

[lancea]

Okay on the RAW mode. I said to myself that you'd surely know that :)

Not sure if I'm misunderstanding you again - but are you saying that you are judging the colours based on what you see on your monitor? While I'm new to colour management, I don't know why you'd immediately convert to the lab's profile. It only has relevance at the lab. When you are viewing the image on your calibrated monitor you must do so using the monitor profile. There's no point viewing the image when it's converted to the lab profile.

Assuming you have a perfectly calibrated monitor and adjust the look of the image using the monitor profile to what you want. You then convert to the profile supplied by the lab and send the file to the printer. If the resulting print doesn't look as you expected, then their profile isn't right.

[pcasciola]

Here's the best I can come up with to illustrate the problem. Unfortunately I can't really post an accurate representation of the print, but lets just say it's quite a bit more purple than the image on the right which is with the Agfa profile applied and CMYK proof colors, while the actual jersey color is closest to the image on the left which is aRGB.

From left to right the only differences are color profiles and proof colors:
aRGB, sRGB, Agfa Laser III profile applied to aRGB image, and the Agfa Laser II profile with CMYK proof colors.

http://www.casciola.com/pics/profiles.jpg

[lancea]

Any differences look pretty subtle to me. I honestly don't know what you should expect if you convert an image to a printer profile and view it on a monitor. The "curves" of a printer will be different, and different again for each paper type. The ideal is that the lab profile can be relied on to give accurate colour.

Perhaps the only way you can prove the lab is at fault is to buy a commercial test chart and image file. Send the file to the lab then compare the returned print with the test chart. If they don't match then beat your way to the door of the lab! If your monitor doesn't match the test chart then you'd have to adjust your monitor profile to match.

Or - can you create your own print that looks just like you want, and take that to the lab with the file?

I'm sure it's possible to do what you say in the last paragraph of your first post - but that's way out of my depth. I learnt a lot from the drycreekphoto site, so hope that helps you.

[Bob_A]

I've been noticing that a lot of my post processed shots come back from the photo lab not even close to matching what I see on my display, especially with some deep blues and red hues. So I just invested in a Spyder 2 Pro and calibrated my monitor last night. It does seems somewhat better, but still different, so I think I need to figure out the correct way to use the various ICC profiles. My print shop provided me with the profiles to match the paper he uses (Agfa Laser III) but I am unclear as to when I should apply this profile. If I shoot RAW aRGB, should I convert to the Agfa profile immediately after converting the RAW and before doing any other edits that might affect the color balance?

Also, I purchased the PrintFix scanner with the Spyder 2 which will help me calibrate my own printers, but I'm wondering if this device can also be used to scan in prints done by the photo lab to tweak the profiles he provided me with? Or, should I just send him a Pantone Chart or GretagMacbeth Color Checker Chart to print and tweak my monitor profile to match that?

If you are using a consumer lab they usually print with automatic enhancements/adjustments turned on that mess up everything that you do in PS. Some consumer labs will turn these off for you, but a lot of these labs have their machines so far out of calibration that the result is even worse when they do that. For some of them, even using ICC profiles won't help.

A good pro lab will print with the auto adjustments turned off, and their equipment is usually properly calibrated.

[blue_max]

Phillip,

Quick question. Are you making photographic prints here or using some form of digital press?

This can make a difference as a digital press will use CMYK and a photographic process will use RGB. The CMYK colour space is much reduced as there are a lot of colours that can not be reproduced using the four-colour process.

Assuming RGB, then you should work on your file with the calibrated monitor until you are happy with the image. This should give you a 'correct' image. Then you need to soft proof using their profile to see what will happen when printed.
If you have had some prints done, you should be in a good position to see how accurately you can view the mis-match of colours. Have a play with the proof options in Photoshop (if that is what you are using).

If you need accurate colour and have to use this lab, then you can get printer profiling kits. This is where you output a file of colour swatches, send them away and get a profile back which maps the changes in colour. You can get a copy of the chart and shoot with your digital camera and do the same thing. It all depends on how far you want to take it. That approach does require the lab to be at least consistent!

It's a real problem, but having your monitor calibrated gives you a head start. At least that part is not going to vary.

I have very little clue what I am talking about here, but in general, your file should be fine and it's just what the printer does to it that you need to try and predict. If you can get to that point, then you may be able to duplicate the file and adjust it until the predicted output is nearer your ideal.

Graham

[pcasciola]

It sounds like I need to just try a few different pro labs and request no auto adjustments. The differences may look subtle on the monitor, but the print is much further off. I knew I couldn't accurately show what's going on, but I at least wanted to show how different they looked just with the Agfa profile applied.

Graham, I like the idea of sending the color swatch. I'm just hoping the Colorvision PrintFix package I bought has an option for this, as it seems to be more geared toward calibrating inkjet printers. If I can get a JPEG out of this software I can send it off to the photo lab to be printed and than scan it in with the swatch scanner so it can create an accurate profile.

[blue_max]

It sounds like I need to just try a few different pro labs and request no auto adjustments. The differences may look subtle on the monitor, but the print is much further off. I knew I couldn't accurately show what's going on, but I at least wanted to show how different they looked just with the Agfa profile applied.

Graham, I like the idea of sending the color swatch. I'm just hoping the Colorvision PrintFix package I bought has an option for this, as it seems to be more geared toward calibrating inkjet printers. If I can get a JPEG out of this software I can send it off to the photo lab to be printed and than scan it in with the swatch scanner so it can create an accurate profile.

I would definitely have a word with the lab – at least to pursuade them to do the colour test for nothing! They may be interested in helping you out as you may become a valued customer and the results might benefit their business in general.

The only problem with the swatch method is the scanning in may impart it's own colour bias, so you are corrupting the data several times. The one's I am thinking of are where you take an industry standard (http://************/8k6vj) swatch card and you get a file that is accurate. You send the file to be printed and then send the result to the company who scan it with a densitometer and send you the profile. If you scan it in, how do you know you haven't changed the colours?

Actually the company in the link, who I bought my Monaco Optix XR are very helpful and would probably be able to offer advice. I am sure there are similar companies in the states.

I would be interested in your solution if you go down that route.

Graham

[arunchs]

What is the rendering intent you are using for conversion? Check your color management settings. Unless it is set to Perceptual Intent, you might loose out on deep colors, which is what seems to be happening here.

[chtgrubbs]

Dry Creek Photo has a tutorial on how to utilize custom profiles. Check this page:
http://www.drycreekphoto.com/Frontier/using_printer_profiles.htm
I am using their profile for my local Costco and have gotten great results.