strange "Curves" behavior w/ large files–PS 7.0

Hi all,

I recently scanned a bunch of B&W negs at full resolution w/ Nikon 4000 scanner (in grayscale), which gives ~20 Mb files. I’m trying to do some "Curves" corrections. I create the control points I need and drag them around and the image reflects the changes made, as it should.

So far so good, but here it gets weird. when I click "Save" the final saved image is not the image as previewed; there is some change but never as extreme as what I set up. This is driving me nuts. I’ve tried this on three different computers so it seems not to be a function of a corrupted file or a ghost in the machine. If I reduce the file size Curves works just fine, but at some point (as yet undetermined) over a couple of Megs this funky behavior starts happening.

As an experiment I also tried converting to RGB color (~60 Mb), since I have not been working much in grayscale up until now. The same problem persists. I have not had occasion to make major Curves corrections to large files before now so I am unsure whether this problem has always persisted. I’m tempted to reinstall PS 6, just to see if the same thing happens.

Here’s one clue, maybe, but I can’t figure out what difference it would make. This problem seems more pronounced when I am working with images scanned with Silverfast 6.0, with the autosharpening and "Negafix" functions active. I just tried with an image scanned with Nikonscan 3.12. There is still a slight reduction in the "Curves" effect of the saved image vis-a-vis the preview, but nowhere near as drastic as that with the files scanned with Silverfast.

Can anyone shed any light on what might be happening, or how to solve the problem? I suppose I could work with Contrast and Levels, but that would be a sorry and miserable workaround.

Hi all,

I recently scanned a bunch of B&W negs at full resolution w/ Nikon 4000 scanner (in grayscale), which gives ~20 Mb files. I’m trying to do some "Curves" corrections. I create the control points I need and drag them around and the image reflects the changes made, as it should.
So far so good, but here it gets weird. when I click "Save" the final

image is not the image as previewed; there is some change but never as extreme as what I set up. This is driving me nuts. I’ve tried this on

different computers so it seems not to be a function of a corrupted file

a ghost in the machine. If I reduce the file size Curves works just fine, but at some point (as yet undetermined) over a couple of Megs this funky behavior starts happening.

As an experiment I also tried converting to RGB color (~60 Mb), since I

not been working much in grayscale up until now. The same problem

I have not had occasion to make major Curves corrections to large files before now so I am unsure whether this problem has always persisted. I’m tempted to reinstall PS 6, just to see if the same thing happens.
Here’s one clue, maybe, but I can’t figure out what difference it would make. This problem seems more pronounced when I am working with images scanned with Silverfast 6.0, with the autosharpening and "Negafix"

active. I just tried with an image scanned with Nikonscan 3.12. There is still a slight reduction in the "Curves" effect of the saved image

the preview, but nowhere near as drastic as that with the files scanned

Silverfast.

Can anyone shed any light on what might be happening, or how to solve the problem? I suppose I could work with Contrast and Levels, but that would

a sorry and miserable workaround.

Hi all,

"Toby" wrote in message

Hi all,

—————————————–
Just curious, are you saving the images directly to HDD before loading

into PhotoShop (if so, what file format?), or does your scanner export

"scanned"-image directly into PhotoShop for editing?

Hi all,

I recently scanned a bunch of B&W negs at full resolution w/ Nikon 4000 scanner (in grayscale), which gives ~20 Mb files. I’m trying to do some "Curves" corrections. I create the control points I need and drag them around and the image reflects the changes made, as it should.
So far so good, but here it gets weird. when I click "Save" the final

image is not the image as previewed; there is some change but never as extreme as what I set up. This is driving me nuts. I’ve tried this on

different computers so it seems not to be a function of a corrupted file

a ghost in the machine. If I reduce the file size Curves works just fine, but at some point (as yet undetermined) over a couple of Megs this funky behavior starts happening.

As an experiment I also tried converting to RGB color (~60 Mb), since I

not been working much in grayscale up until now. The same problem

I have not had occasion to make major Curves corrections to large files before now so I am unsure whether this problem has always persisted. I’m tempted to reinstall PS 6, just to see if the same thing happens.
Here’s one clue, maybe, but I can’t figure out what difference it would make. This problem seems more pronounced when I am working with images scanned with Silverfast 6.0, with the autosharpening and "Negafix"

active. I just tried with an image scanned with Nikonscan 3.12. There is still a slight reduction in the "Curves" effect of the saved image

the preview, but nowhere near as drastic as that with the files scanned

Silverfast.

Can anyone shed any light on what might be happening, or how to solve the problem? I suppose I could work with Contrast and Levels, but that would

a sorry and miserable workaround.

TIA

Toby

Many thanks to all who made suggestions. I zoomed up to
100% and found that indeed the problem rested in the fact that a reduced image "overstated" the case. At full size the preview and final result are identical. This means that
unfortunately I cannot used the image to judge what effect Curves will have, unless I zoom up to 100%, in which case I just see a tiny portion of the full scan. Time for a bigger monitor I guess….

Hi all,

I recently scanned a bunch of B&W negs at full resolution w/ Nikon 4000 scanner (in grayscale), which gives ~20 Mb files. I’m trying to do some "Curves" corrections. I create the control points I need and drag them around and the image reflects the changes made, as it should.

but at some point (as yet undetermined) over a couple of Megs this funky behavior starts happening.

Hi all,

I recently scanned a bunch of B&W negs at full resolution w/ Nikon 4000 scanner (in grayscale), which gives ~20 Mb files. I’m trying to do some "Curves" corrections. I create the control points I need and drag them around and the image reflects the changes made, as it should.
So far so good, but here it gets weird. when I click "Save" the final saved image is not the image as previewed; there is some change but never as extreme as what I set up. This is driving me nuts. I’ve tried this on three different computers so it seems not to be a function of a corrupted file or a ghost in the machine. If I reduce the file size Curves works just fine, but at some point (as yet undetermined) over a couple of Megs this funky behavior starts happening.

As an experiment I also tried converting to RGB color (~60 Mb), since I have not been working much in grayscale up until now. The same problem persists. I have not had occasion to make major Curves corrections to large files before now so I am unsure whether this problem has always persisted. I’m tempted to reinstall PS 6, just to see if the same thing happens.
Here’s one clue, maybe, but I can’t figure out what difference it would make. This problem seems more pronounced when I am working with images scanned with Silverfast 6.0, with the autosharpening and "Negafix" functions active. I just tried with an image scanned with Nikonscan 3.12. There is still a slight reduction in the "Curves" effect of the saved image vis-a-vis the preview, but nowhere near as drastic as that with the files scanned with Silverfast.

Can anyone shed any light on what might be happening, or how to solve the problem? I suppose I could work with Contrast and Levels, but that would be a sorry and miserable workaround.

TIA

Toby