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colour consistency

PostPosted: Tue Feb 09, 2010 10:28 pm
by ambermai23
Hi everyone,

So I figured out how to scan without getting a blue cast but now I'm struggling to get consistent colours.
From what I've read, the best way to get the maximum tonal range and work within the widest gamut is to use the auto adjust tool with the correct Negafix setting. The problem seems to be that if I use the auto adjust tool, the colour cast changes slightly from frame to frame - which is really frustrating to deal with in photoshop. I am scanning landscapes, all shot on Fuji 400 Pro H film in identical lighting. The blue skies are different from scan to scan.
So, is the best option just to forget about setting black point and white point and using auto adjust? Or is there an easy fix in Photoshp (please don't talk to me about "Match Color" in PS, it is NOT working for me.

Thanking you!
Amber

Re: colour consistency

PostPosted: Thu Feb 11, 2010 9:16 am
by LSI_Ketelhohn
Dear Amber,

The NegaFix settings are adjusted individually for each image.

Sometimes for a series of images this results in different color moods for individual images.

If you want to scan a range of images with the same settings you only have to deactivate the "auto" function in the Negafix dialog.
You should first let NegaFix adjust to a "general" image.
If you then switch off the auto setting in the NegaFix Expert Dialog (Ai) subsequent images will be scanned with exactly the same settings.

This works best for images which look similar.


kind regards
Arne Ketelhohn.

Re: colour consistency

PostPosted: Thu Feb 11, 2010 4:53 pm
by ambermai23
Hi Mr Ketelhohn,
I only have Silverfast SE - does this mean I need to upgrade to AI?
THank you for your reply,
Amber

Re: colour consistency

PostPosted: Fri Feb 12, 2010 12:14 pm
by LSI_Ketelhohn
ambermai23 wrote:I only have SilverFast SE - does this mean I need to upgrade to AI?

No in SilverFast Se the auto selection hook is directly visible in the NegaFix dialog.
In Ai you need to open the experts dialog.

kind regards
Arne Ketelhohn.

Re: colour consistency

PostPosted: Tue Mar 23, 2010 2:21 pm
by ljkuzel
The reason you get different result with different images is because of the differences in the actual colors in the image itself. I used to do automated prints for a color photo lab and as you ran the film through the machine you would look for large areas of color. The machine didn't know specific colors, just the overall amounts of different colors. Lets say someone had on a blue shirt (yellow in the negative). That's going to influence the color to the yellow end because the machine sees more blue, and depending on the amount of image the shirt takes up you would hit the correction for that color, either plus blue or minus yellow, don't remember which it would have been, coulda been operators choice.

If you want to see this, when in auto mode make a small selection of an area of the image and move it around the image. You will see it change color depending on the changes in colors in the image. Include more grass, more magenta in the image, blue sky, more yellow.

You can have the inconsistent when you take an image with a camera on auto white balance. Large amounts of color will make a difference in the color balance. If you take a picture of a subject on grass, then take the same picture on blacktop you will see a color shift.

Larry