Scan color
August 13, 2005 6:37 PM Subscribe
A question about film scanners.
I have a CanoScan 8000F, which has film scanning capabilities. Generally it is very good for my purposes, except for one negative-scanning problem which I can't seem to resolve despite extensive Googling and forum lurking - I've even tried contacting Canon tech support - hah!
The scanner previews the negatives and makes an automatic adjustment for exposure and color. The problem is that the color adjustment is based on the content of the photo. So, if there's a shot with lots of green grass, the scanner thinks there's an imbalance of green, and overcompensates by introducing a magenta cast. Similarly, if there's a lot of blue sky the scanner will overcompensate with yellow, and the sky turns green-ish. While these color casts can be neutralized to some extent in post-processing, it's a pain when half a dozen shots of a similar subject end up with slightly different color casts due to varying amounts of (for example) grass in the shot.
With the bundled software there is an "Auto-tone" function, which I would have thought is the cause of the problem, but turning this off makes no difference to the color analysis. It's as if I need another function to force the scanner to ignore the individual RGB channels, and adjust its exposure based purely on the overall luminesence of the negative.
I've also tried VueScan, but there is a problem with the way it handles negative scanning with the 8000F (very noisy) and Ed doesn't seem to have got around to fixing this yet.
I have a CanoScan 8000F, which has film scanning capabilities. Generally it is very good for my purposes, except for one negative-scanning problem which I can't seem to resolve despite extensive Googling and forum lurking - I've even tried contacting Canon tech support - hah!
The scanner previews the negatives and makes an automatic adjustment for exposure and color. The problem is that the color adjustment is based on the content of the photo. So, if there's a shot with lots of green grass, the scanner thinks there's an imbalance of green, and overcompensates by introducing a magenta cast. Similarly, if there's a lot of blue sky the scanner will overcompensate with yellow, and the sky turns green-ish. While these color casts can be neutralized to some extent in post-processing, it's a pain when half a dozen shots of a similar subject end up with slightly different color casts due to varying amounts of (for example) grass in the shot.
With the bundled software there is an "Auto-tone" function, which I would have thought is the cause of the problem, but turning this off makes no difference to the color analysis. It's as if I need another function to force the scanner to ignore the individual RGB channels, and adjust its exposure based purely on the overall luminesence of the negative.
I've also tried VueScan, but there is a problem with the way it handles negative scanning with the 8000F (very noisy) and Ed doesn't seem to have got around to fixing this yet.
Workaround: Use "Image->Adjustments->Match Color..." in Photoshop. I've found it to be a limited command, at least in my hands, but it might work.
Load your image which you'd like the others match.
Select "Match Color...", and "save statistics" for that file.
Open another file from the series with a color cast.
Click the record new action icon.
Select Match Color, "load statistic" select your .sta file.
Stop recording the action.
For more control, either check the dialog control box next to the action name, or for a less cluttered screen I guess you could instead add Edit->"Fade Match Color..." to the action, and select the dialog control box on that step only.
If you name the statistics file something generic, like "scanmatch.sta", and save over the file when you do a new set of scans, you won't have to modify the action.
You can run the action as a batch, and have it append an extension to the file name. i.e. "scan001.tif" gets color matched and turns into "scan001matched.tif".
These other alternatives are probably even less appealing:
Silverfast doesn't list the 8000F as a supported scanner, but I guess it never hurts to try.
If the 8000 uses the same software as previous Canoscans, there's a slim chance that previous releases of the software don't behave the same.
posted by Jack Karaoke at 12:58 AM on August 14, 2005
Load your image which you'd like the others match.
Select "Match Color...", and "save statistics" for that file.
Open another file from the series with a color cast.
Click the record new action icon.
Select Match Color, "load statistic" select your .sta file.
Stop recording the action.
For more control, either check the dialog control box next to the action name, or for a less cluttered screen I guess you could instead add Edit->"Fade Match Color..." to the action, and select the dialog control box on that step only.
If you name the statistics file something generic, like "scanmatch.sta", and save over the file when you do a new set of scans, you won't have to modify the action.
You can run the action as a batch, and have it append an extension to the file name. i.e. "scan001.tif" gets color matched and turns into "scan001matched.tif".
These other alternatives are probably even less appealing:
Silverfast doesn't list the 8000F as a supported scanner, but I guess it never hurts to try.
If the 8000 uses the same software as previous Canoscans, there's a slim chance that previous releases of the software don't behave the same.
posted by Jack Karaoke at 12:58 AM on August 14, 2005
This thread is closed to new comments.
posted by kindall at 7:10 PM on August 13, 2005