odd artifacts from blending options, photoshop

[Pigeonkill]

I was wondering if anybody encountered a similar problem with photoshop and could help. I was using the layer blending option with multiply at opacity 75% ...and I get these odd artifacts. The layer with the blending option is just copy and paste of the bottom background layer and placed on top,(see the image below)

I tested new drivers, screen resolution, color settings...in hope to fix it, but the results are the same. I'm using a SyncMaster 913v radeon 1600.

I also notice that when I take a screenshot and export it to photoshop the image is made lighter...not sure if it's because of the lcd screen?

http://www.polykarbonbbs.com/attachment.php?attachmentid=841&d=1152127097

Thanks in advance.

[Snarfevs]

Cannot replicate this effect. What version of photoshop are you using?

Taking screenshots and having colours/luminances change (as well as colours changing when saving for web etc) is generally diagnostic of perceptibly different colour space calibrations for photoshop vs. the rest of your system. Hit shift-ctrl-K and check to make sure nothing seems wildly out of order.

[CaneHoyer]

At first: a screenshot has not the same color profile you use in PS so the image looks different and is different in color values!

To your problem:

- did you check, if you video card is set to 32bit colors?

- the artefacts to me might be some monitor problems, mainly seen on LCDs, not the video card, but the monitor!
If this effect appears, try to zoom in and out the window, if the effect stays, it shouldn't be the monitor.
If it's the monitor, a new monitor driver might help, but the problem also could be the hardware itself.

- another possibility might be PS. I got a related problem years ago on a MAC using PS 6 with some filters. It only appeared with some filters. I had to reinstall the filter plugins. but I think this is not your problem.

[Pigeonkill]

I was using photoshop 7.0, and with 32 bits. I got an interesting answer at the adobe forums too

"--------------------------------------------------------------------------------
Pierre Courtejoie - 11:38pm Jul 5, 06 PST (#3 of 4)

There was a bug in PS7's code that produced dark lines when using muultiply in lowered opacity on a dual processor setup.
I am not sure if the 7.01 update fixes that bug, but you should apply it anyways, or upgrade to a newer version of Photoshop.
"

So I just installed Adobe Photoshop cs2, a bit slower on my system but has no problems with the multiply opacity settings. Thanks for all the help :)

[Pixeldragoon]

I had this same problem as well, I assumed it had something to do with my scanner. Apparently not.

[Peskykid]

I'm not sure if these are genuiine atifacts or just a screen problem. have you tried flattening the image to find out if they're there when it's only one layer?

[Ahwatukee]

I too am having these strange banding artifacts with Photoshop 7. I am also on a dual processor setup.

The artifacts are not a display problem. It's something to do with Photoshop 7's code, for sure.

They only appear IN CERTAIN PERCENTAGES OF FILL/OPACITY when using the Multiply layer blending mode.

Since dual processors were mentioned, this may possibly be a cause, as I am on a Core2Duo... The lines are always vertical, and dark.

I made a dummy photoshop file for an example. I copied the background, pasted into a new layer, inverted that layer, set it on multiply and dragged the fill slider down. (The same results and numbers were achieved using the opacity slider as well.)

Check out the almost perfect pattern:

0 - 12% Banding (12 steps in opacity.)
13-24% No banding (11 steps in opacity.)
25-37% Banding (12 steps in opacity.)
38-49% No banding (11 steps in opacity.)
50-62% Banding (12 steps in opacity.)
63-75% No banding (12 steps in opacity.)
76-87% Banding (11 steps in opacity.)
88-100% No banding (12 steps in opacity.)

Here is a JPEG of the banding.

http://img233.imageshack.us/img233/1310/photoshop7multiplybandiwk5.jpg

It's really made things complicated, because I'm a big multiply user, and all old Photoshop files I've had to go back to to make changes are nearly impossible to edit. I'm lucky I have flattened versions.

I have found somewhat of a work-around if you're like me and use PS7, and need to use the multiply blending mode. Keep it at 100%, and to adjust the level that it multiplies the layer instead of using the opacity or fill, use brightness/contrast, or levels to brighten the layer, therefor lessening the multiplication of that layer. The only downside to this is once you've selected the appropriate level, there's no going back, so you're going to have an awful lot of duplicate layers.

Photoshop updates don't fix this, and they order you to buy a new version. It's quite disappointing that they won't support serious flaws in their product just because it's been out for a few years. This is NOT like asking AutoZone to carry parts for a Model T Ford.