PDA

View Full Version : Printers, color management, & all that jazz


shaunyc
1st of November 2001 (Thu), 07:42
I took the plunge - after two years of managing and distributing all of my shots on screen or over the web, I've bought myself an Epson C60 printer. And I'm really impressed with it. Prints great photos.

The thing is, although they are pleasing, they aren't quite the same as the screen image.

I have heard of monitor calibration (and have run Adobe Gamma so that my monitor should be pretty good) and know that I also have to do printer calibration too. But I'm lost about what you do where.

I use PaintShopPro7 and PhotoshopElements (can't afford full-blown Photoshop this year). PSP has some color management stuff built in, and I have selected both my monitor profile and the default printer profile for my printer. I have selected Perceptual Rendering Intent as the help file says it's best for photos.

OK so far. Now, when I go to print the image, the printer driver gives me another host of color management options, ranging from detailed control over CMY and HSL to all sorts of photo enhancement things like sharpness, contrast, vividness - plus a delightfully obscure checkbox labelled "Digital Camera Correction".

Now I'm not so sure what I'm up to. I have my profiles selected in PSP. Should I choose the sRGB option in the printer driver, or no color management or Windows ICM?

I've chosen a default printer profile, but does this match the paper I'm using? And does it matter?

I know that Pekka assigns a specific D30 profile to his pictures when he loads them into PS - is there a G1 profile, and if so will I benefit from using it? And does anyone have one?!

If anyone has successfully navigated this path, I'd be grateful to hear what I should do, what can be ignored or defaulted, and what pitfalls I am likely to encounter.

With thanks (in advance),
Shaun

Dick
3rd of November 2001 (Sat), 11:40
Color Management is about understanding the level of information that is included with the color file at the source and then making sure that you understand how that information is interpreted or changed by each program. Color files are only "relative" to each other unless a color profile is included which describes how the color file relates to absolute color via ICC defintions.

Here are some important facts.
1) Color Management must be supported by the Operating System. Mac does. Win 2K and WinXP do support. Later versions of Win98 do. I don't know about Win Me. If the operating system doesn't support it Color Management won't work.

2) The devices that produce color files may or may not include color profile information. The Canon D30 DOES NOT include color profile information the new Canon D1 does include color profile information. I don't know about the other Canon digital but I would guess they DON'T.

3) The monitor needs to be calibrated to an absolute standard. That is it needs to produce the correct absolute color from a color file. Adobe Gamma is an attempt to do this but it is a POOR attempt. The reality is that it is very difficult or impossible to produce a profile by eye. I calibrate my monitor with a program called Prove It! which uses a colorimeter which sticks on the screen during calibration. These colorimeters are sometimes called "spyders". This program shows color files on the screen and then measures the color produced in RGB. It then provides the "monitor profile" to the video card so it produces the true color.

4). The image editing program (Photoshop etc) needs to utilize the color profile information provided. I know that Photoshop 5.5 and 6 do provide this facility. Photoshop 6 manages it very effectively and this is one of the big advances of Photoshop 6. I don't know about other programs.

5). The printer drivers need to be able to take color profile information and utilize it to produce the correct colors on paper. Newer EPSON printers have this facility. I don't know about other brands and older Epsons.

6) Most consumer hardware and software assume the color profile is sRGB. sRGB has a pretty decent color range but in fact does not represent all the colors that (in my case) a Canon D30 can see and all the colors that a Epson 890 can produce.

My work flow with the D30 is as follows.

Import the D30 file via Breeze Browser. Assign it in Photoshop to the Adobe RGB profile. This allows the color file to cover the wider gamut expressed in Adobe RGB and tells all other files to interrupt this color file as Adobe RGB. I then color adjust the photo information using my calibrated monitor. When I save the file the color is the way I want it and all other programs will see it as an Adobe RGB color file.

I then print it using "Printer Color Management" and "Advanced" "ICM". The colors print out as a match for what I saw on the screen.

"Converting Color Space" which is a Photoshop command converts the color file from one gamut to another. You really don't want to do this except in specific output cases. Original files should not be "converted" as it throws away color imformation. "Assign profile" doesn't change the original color file but simply how the file is interrupted.

When I get ready to produce a "web photo" I convert the file from Adobe RGB to sRGB because most browsers interpret the information as sRGB. An Adobe RGB file viewed as an sRGB will look washed out.

I posted an example of this on the Photo files here on the site under the title "Polish Arabian Horse". It will show this effect.

Color Management takes a fair amount of reading and understanding but if you want to produce great photo prints it is a must.

I hope this helps.

shaunyc
5th of November 2001 (Mon), 22:18
Excellent! Thanks for taking the time to type such a detailed reply.

Shaun

ronb359
13th of November 2001 (Tue), 20:55
I just bought PSP7. I'm trying to figure out how to use my old Printshop profiles. Can you tell me how your using profiles in PSP?

shaunyc
15th of November 2001 (Thu), 08:07
Hmm, I'm not sure what Printshop is, but I'll assume that it is some sort of printing utility (a wild guess based on the name) or maybe a mistype of Paintshop :-)

I'm not doing anything wildly sophisticated with profiles. Under File->Preferences->Color Management I check the Enable Color Management checkbox and select Basic Color Management.

I had used Adobe Gamma to calibrate my monitor (in the absence of the more sophisticated option mentioned above). This generated a profile which appears in the drop down Monitor Profile list.

I have enabled Automatic color profile association for my Epson printer. This is on the Color Management tab of the (Windows) printer preferences dialog box. The only option was the profile that came with the printer, and is also the profile that appears in the Printer Profile drop down list in the PSP color management dialog. (Phew). My guess is that if you have other profiles available in the printer preferences dialog, they would also be available for selection in PSP.

So far I'm just beginning to learn what all this mean/does. I found that the Adobe Gamma profile and the standard printer profile give pretty good results (to my untrained eye). Let me know if you have obtained profiles from elsewhere that you find to be preferable.

Shaun