iPhoto 6 and ColorSync Embedding

[n8gray]

I'm a little bit (ok, a lot) confused about the ColorSync embedding feature in iPhoto 06. I've got a Nikon d50 and I started experimenting a bit with colorspaces. The camera has two modes that produce sRGB and one that produces Adobe RGB. I took a photo in each, imported them into iPhoto, and also copied them straight off the memory card to see how the camera wrote them. The result was that each photo got the following colorspace (according to Preview.app):

sRGB, copied from camera: (none)
sRGB, imported into iPhoto: Camera RGB

Adobe RGB, copied from camera: Adobe RGB (1998)
Adobe RGB, imported into iPhoto: NIKON D50

I can see why iPhoto would embed a "Camera RGB" profile into an untagged image, but why did it change the image that already had a profile? Even more confusing is that neither Preview nor ColorSync Utility even list a profile called "NIKON D50". I'm guessing the name comes from the fact that that's the name that the camera gets when it's mounted as a disk, but I have no idea how to learn anything else about it.

Anyhow, if somebody understands what's going on I'd be happy if you could clarify it for me.

Thanks,
-n8

 

[Bruce McL]

It is confusing. If you try these suggestions it may help, or may just make you more confused!

1. Try checking the profiles in Photoshop or Colorsync Utility.

2. Open Colorsync utility with the camera connected. Check the devices tab and look at what the default profile is.

3. Do a "Find" in the Finder and click on "Other Places."" Click on your hard disk, and pick the Library folder. Do the same for System. Now do a find for Nikon and see if the profile shows up. This is how I found the Canera RGB profile that Apple uses. Maybe the Nikon profile will show up.

 

[TheQ]

The Nikon (or Canon etc..) named colour profile you are seeing is still Adobe RGB (1998) but retagged with a different name. I assume that Apple rename it due to the fact they alter the original embeded profile to add two additional pieces of information, a 'vcgt' tag (Video Card Gamma Tag), and a 'ndin' tag (Native Display Information), the rest of the embedded color profile is otherwise intact.

However, it gets more confusing when there isn't an embedded profile in the image.

When you import an untagged image, despite the fact that it might have ColorSpace=1 (sRGB) in the EXIF data, iPhoto/Image Capture will, by default, use "Camera RGB" as the colour space when importing the image rather than "sRGB Profile".

The issue is that Camera RGB isn't actually sRGB, it's Apple's 2.2 gamma version of "Generic RGB" (which is the official "default" colour space OSX will use for any untagged image). Technically this is simply WRONG, as the untagged image is actually sRGB and not Generic RGB with 2.2 Gamma. Fortunately the profile only differs by a very small amount, so it's unlikely you could even see the difference.

Seeya...Q

 

[n8gray]

The Nikon (or Canon etc..) named colour profile you are seeing is
still Adobe RGB (1998) but retagged with a different name. I assume
that Apple rename it due to the fact they alter the original
embeded profile to add two additional pieces of information, a
'vcgt' tag (Video Card Gamma Tag), and a 'ndin' tag (Native Display
Information), the rest of the embedded color profile is otherwise
intact.

Ok, as long as it's preserving the profile I don't care too much about the name.

However, it gets more confusing when there isn't an embedded
profile in the image.

When you import an untagged image, despite the fact that it might
have ColorSpace=1 (sRGB) in the EXIF data, iPhoto/Image Capture
will, by default, use "Camera RGB" as the colour space when
importing the image rather than "sRGB Profile".

The issue is that Camera RGB isn't actually sRGB, it's Apple's 2.2
gamma version of "Generic RGB" (which is the official "default"
colour space OSX will use for any untagged image). Technically this
is simply WRONG, as the untagged image is actually sRGB and not
Generic RGB with 2.2 Gamma. Fortunately the profile only differs by
a very small amount, so it's unlikely you could even see the
difference.

Interesting. I had tried embedding Nikon sRGB in one of these Camera RGB files and wasn't sure anything changed, which agrees with what you've said. Thanks for the insight!

 

[reefonline]

hey hey, well, i got a question, does this iphoto support raw files???

i have been using a d70 for quite some time (my first dslr) and just got a d200, honestly, im not too happy with picture project, and i would love to get my hands on a copy of aperture (which looks pretty good for image management, but i was just wondering, will iphoto do the job for now? will i lose quality on my photos?
anything else i should know???

thanx
--
http://reefonline.deviantart.com
http://www.reefonline.com

 

[Bruce McL]

When you import an untagged image, despite the fact that it might
have ColorSpace=1 (sRGB) in the EXIF data, iPhoto/Image Capture
will, by default, use "Camera RGB" as the colour space when
importing the image rather than "sRGB Profile".

If you go to ColorSync Utility after you connect the camera but before you make the import into iPhoto you can click on the devices tab, click on the camera and change the profile that iPhoto uses. I have one camera set to Adobe's sRGB with all the numbers after it, another camera set to a custom profile I made for it. I find that ColorSync Utility will "forget" about the profiles I assigned every once in a while. So I nearly always check before importing.

The issue is that Camera RGB isn't actually sRGB, it's Apple's 2.2
gamma version of "Generic RGB" (which is the official "default"
colour space OSX will use for any untagged image). Technically this
is simply WRONG, as the untagged image is actually sRGB and not
Generic RGB with 2.2 Gamma.

It is wrong, no doubt. I wish they'd just do it right. Apple is sloppy with about color management with other programs as well such as Safari and iWeb. I don't like to see that.

 

[TheQ]

When you import an untagged image, despite the fact that it might
have ColorSpace=1 (sRGB) in the EXIF data, iPhoto/Image Capture
will, by default, use "Camera RGB" as the colour space when
importing the image rather than "sRGB Profile".

If you go to ColorSync Utility after you connect the camera but
before you make the import into iPhoto you can click on the devices
tab, click on the camera and change the profile that iPhoto uses. I
have one camera set to Adobe's sRGB with all the numbers after it,
another camera set to a custom profile I made for it. I find that
ColorSync Utility will "forget" about the profiles I assigned every
once in a while. So I nearly always check before importing.

Yes, however I have found that iPhoto will totally ignore whatever profile is selected in ColorSync Utility and just use Camera RGB anyway. Image Capture will embed the correct profile, but iPhoto ignores it.

The issue is that Camera RGB isn't actually sRGB, it's Apple's 2.2
gamma version of "Generic RGB" (which is the official "default"
colour space OSX will use for any untagged image). Technically this
is simply WRONG, as the untagged image is actually sRGB and not
Generic RGB with 2.2 Gamma.

It is wrong, no doubt. I wish they'd just do it right. Apple is
sloppy with about color management with other programs as well such
as Safari and iWeb. I don't like to see that.

Actually I have found Apple's colour management to be spot on, the issues I once had were the result of screen calibration (or rather the lack of it), and using 1.8 gamma instead of 2.2. The only problem I have now is with iPhoto 6 using the default rather than current ColorSync profile assigned to my cameras/card reader.

Seeya...Q

 

[Bruce McL]

When you import an untagged image, despite the fact that it might
have ColorSpace=1 (sRGB) in the EXIF data, iPhoto/Image Capture
will, by default, use "Camera RGB" as the colour space when
importing the image rather than "sRGB Profile".

If you go to ColorSync Utility after you connect the camera but
before you make the import into iPhoto you can click on the devices
tab, click on the camera and change the profile that iPhoto uses. I
have one camera set to Adobe's sRGB with all the numbers after it,
another camera set to a custom profile I made for it. I find that
ColorSync Utility will "forget" about the profiles I assigned every
once in a while. So I nearly always check before importing.

Yes, however I have found that iPhoto will totally ignore whatever
profile is selected in ColorSync Utility and just use Camera RGB
anyway. Image Capture will embed the correct profile, but iPhoto
ignores it.

I have very good luck in 10.4 assigning profiles before import with Colorsync Utility. Are you sure we are talking about the same thing? Here is where I do it in Colorsync Utility.

 

[TheQ]

Yes, we are talking about the same thing. Image Capture will use whatever profile you specify in ColorSync Utility, but iPhoto 6 will completely ignore it and use Camera RGB, for both my cameras and my card reader.

Seeya...Q

 

[Janice Legler]

Q,

Do you have an Apple Display monitor? I am a bit confused here--does it work better set at 1.8 gamma--or 2.2?

Actually I have found Apple's colour management to be spot on, the
issues I once had were the result of screen calibration (or rather
the lack of it), and using 1.8 gamma instead of 2.2.

Have you solved this portion yet?

The only
problem I have now is with iPhoto 6 using the default rather than
current ColorSync profile assigned to my cameras/card reader.

Seeya...Q

Thanks,
Janice
--
Have camera, will travel

http://www.pbase.com/jwlegler
http://homepage.mac.com/janice_legler/

 

[macgaspode]

I can confirm this. Even happens with iPhoto 6.0.1.

Anybody with a new idea?

 

[macgaspode]

You might be interested in reading this:

http://discussions.apple.com/thread.jspa?threadID=360401