Levels preview problem

DN
Posted By
Douglas_Nelson
Feb 16, 2004
Views
830
Replies
5
Status
Closed
I discovered this while trying to help someone else out, and I can’t think of the reason:

On a layer filled with black I use the add noise filter to make it very grainy. Then I adjust the levels of that layer so that in the preview it looks like a starfield (dragging the black 3/4 over to the right usually does it). Then I click OK and the noise is back, only slightly modified.

The solution is to blur the noise slightly before adjusting levels, but I can’t figure out why the preview and the final image differ so greatly.

Even using a levels adjustment layer makes it look like the starfield until you merge, then it zaps back to just a very grainy level.

Is this a bug, or is there some point of theory here I’m not taking into consideration? I tried different versions of PS, even Elements, all the same.


– Doug Nelson

==============================
http://www.retouchpro.com — the #1 online community for retouchers and restorers

Master Retouching Hair

Learn how to rescue details, remove flyaways, add volume, and enhance the definition of hair in any photo. We break down every tool and technique in Photoshop to get picture-perfect hair, every time.

CC
Chris_Cox
Feb 17, 2004
It sounds like you’re zoomed way out (less than 50%) and seeing the difference between the preview and actual pixels….
DN
Douglas_Nelson
Feb 17, 2004
Chris:

That was it, thank you. Plus zooming in to test this taught me a bit about how PS generates noise.

But now you have me freaked out about the accuracy of the image display when viewing at 25% zoom level 🙂


– Doug Nelson

==============================
http://www.retouchpro.com — the #1 online community for retouchers and restorers
Y
YrbkMgr
Feb 17, 2004
But now you have me freaked out about the accuracy of the image display when viewing at 25% zoom level

For whatever it is worth, a lot of folks complain that their layer styles aren’t applied when they accept the dialog, claming that the style has disappeared. The reason is because anything other than 100% mag in Photoshop is an approximation, and images are best evaluated at 100%. In their case it looks unapplied, until they zoom in.

Peace,
Tony
DJ
David_J
Feb 17, 2004
If you want starfields, visit <http://www.diardsoftware.com/>
DN
Douglas_Nelson
Feb 17, 2004
Thanks David, excellent link.

But actually I was building a snowstorm 🙂


– Doug Nelson

==============================
http://www.retouchpro.com — the #1 online community for retouchers and restorers

How to Master Sharpening in Photoshop

Give your photos a professional finish with sharpening in Photoshop. Learn to enhance details, create contrast, and prepare your images for print, web, and social media.

Related Discussion Topics

Nice and short text about related topics in discussion sections