Image profiles

[gandini]

OK, Im being stupid here, so can someone clear this up for me?
I open a TIFF image in PS7.01 and attach a profile for color management. The image changes from dark to reasonable. I save the image as a JPG and in Windows (XP) Explorer it looks just fine. I post the image to this forum, or to my website and when viewed in IE6 it looks like the original image (dark) not the balanced image I see in PS or in Explorer.
What happening?

cheers,

[slejhamer]

Gandini,

What do you mean by "attach"? I assume you mean converting to your workspace profile before editing. I don't know about XP's color management capabilities, but for viewing in a web browser or any application that is not ICC compliant I believe you should first convert your processed images to sRGB.

My basic G1 workflow includes:
1. Assign True Color G1 ICC profile during RAW conversion.
2. Open in Photoshop and convert to working color space, which is AdobeRGB for me.
3. After editing the file, if I want to save a JPEG, I convert to sRGB. This would include images saved for the web, or files I send to an online printing service such as Ofoto. For printing at home I keep the TIFF file in AdobeRGB.

If you don't have a G3 profile, I think you would simply open the untagged image and convert to your working space before post-processing.

Let me know if I am doing this incorrectly. Now that I have calibrated my monitor with a Spyder the colors seem very consistent, so I think I have it right.

Regards,

[Roger_Cavanagh]

Mitch has it right. XP makes no difference to his recommendations.

Regards,

[gandini]

Thanks to Mitch and Roger for the confirmation. Your confusion was due mainly to my poor use of the terms assign and convert. This is all new to me. There are no G3 color profiles (.icm files) as yet, but there is an S45 one, which is perhaps useful for working with G3 files.
My problem stems from the following issues:

Because of problems with Canon's G3 SDK, linear conversion of RAW files is not currently possible. However, PowerShovelII allows for the equivalent of Chris Breeze's linear conversion by choosing a gamma of 1.0 and some lookup table (a TIF file.) Absent a G3 LUT, I am using the neutral one provided with PSII. When I convert a G3RAW file using these parameters it comes out very dark (like I am told all linear images do.)
I open the TIF in PS7.01 and then assign an .icm file called AIM RGB=Trinitron D65 G1.00 available from the AIM website. The image still looks bad. I then have to perform some channel mixing but the image looks like crap. If I then save the file as a JPG it looks dark when I post it to the web.
From your post, I sense that I am missing some *conversion* steps. Maybe I should assign the G1.00 profile, then convert to sRGB, perform edits, then save as JPG. OR, perhaps I should assign the profile, perform edits, then convert to sRGB to save as JPG for the web...
Geez, I'm confused.

thanks anyway,

[Roger_Cavanagh]

Philip,

You might be interested to know that the G3 is listed as a supported camera in Adobe's new converter. If you'd like to email me a file, I'll convert it for you.

Regards,

[gandini]

Roger_Cavanagh wrote:
Philip,

You might be interested to know that the G3 is listed as a supported camera in Adobe's new converter. If you'd like to email me a file, I'll convert it for you.

Regards,

Roger:
Thanks for the very kind offer. Chris Breeze just released a beta of 2.5a that does linear conversions for G3 files. Seems to work just fine after a very brief test. Also yesterday I seemed to make some progress on my learning curve about color space and management.
I do have a question for you though: It seems to me that the advantage of linear files is that you can edit in a color space that gives you more "range" of options with a linear image, but eventually you have to convert to some other color space to either print, or display on the web, etc. Huh?

cheers,

[Roger_Cavanagh]

gandini wrote:
I do have a question for you though: It seems to me that the advantage of linear files is that you can edit in a color space that gives you more "range" of options with a linear image, but eventually you have to convert to some other color space to either print, or display on the web, etc. Huh?

cheers,

Philip,

I'll start by answering the second part of your question first. Yes, you do convert from your working space for printing. Although with Photoshop you don't have to actually convert the image file as PS takes care of the conversion using the specified printer profile. If you are sending a file to someone for printing, you might do the conversion so that the correct profile is embedded.

Images on the web are usually best converted to sRGB. However, some people use this as their working space, so, of course, no conversion would be needed.

It's my understanding that linear space gamut for the D30 (and presumably other cameras using raw, but I don't know for a fact) is wider (at least, for some colours) than spaces such sRGB or Adobe RGB. So in the beginning you can work in a wider space such as Wide Gamut RGB or Prophoto RGB. But, at some point, you have to give it away, but I'd rather make that dcision myself in Photoshop than have it done at conversion.

Regards,

[JohnnyE]

This might help:

http://www.powershot.com/powershot2/customer/fvupatch.html

This is a patch for the File Viewer Utility to fix the problem where you get green images when converting S45 and G3 RAW images shot with a custom white balance.

I'm not sure that this is what you need, but it's probably a good thing to have.