Photoshop CC Smart Sharpen Problem

[DeanChriss]

1. Pick sharpening settings for a photo using the normal on-screen image (as opposed to the preview on the tool palette) at 50% magnification.

2. Click OK and put the cursor (now an hour glass) next to some feature on the image.

3. The instant the sharpening is applied and the cursor turns from an hour glass into a normal cursor, the visible amount of sharpening decreases very noticeably.

Note that there is no difference between the tool palette preview and the normal on-screen image preview, but the tool palette preview vanishes as soon as you click OK. The problem here is that at any magnification less than 100% (100% works fine) the previews show significantly more sharpening than is actually applied, based on the on-screen image after the sharpening is applied and also based on printed samples. The difference is enough that I noticed it without going through these steps, but then did what I just described to prove my eyes weren't playing tricks.

I just checked PS CS6 and the displayed previews exactly match the on-screen image after sharpening is applied.

Have others seen this?

[DeanChriss]

Note also that the "Legacy" mode in PS CC has the same problem, but PS CS6 does not.

[Redcrown]

Can't help, other than to half verify. My CC smart sharpen behaves like you describe. Less than 100% previews show more sharpening than actually gets applied.

However, my CS6 behaves the same way. The <100% previews have more sharpening than actual results. Used gross oversharpening in both to test.

Not much surprise there. Common advice has always been to evaluate sharpening at 100%.

[Derek Kemp]

Yes, I have noticed the exact same thing and also noticed (for a long time now) that CS6 does the exact same thing. I actually posted a question about this many moons ago, phrasing it a little differently, but the same thing in essence. A reply was posted by Jeff Schewe, to the effect that "always vue at 100% to see sharpening".
Well, true enough, but doesn't answer why we get this misleading effect that you are asking about, Dean.
DK

[Bart_van_der_Wolf]

Yes, I have noticed the exact same thing and also noticed (for a long time now) that CS6 does the exact same thing. I actually posted a question about this many moons ago, phrasing it a little differently, but the same thing in essence. A reply was posted by Jeff Schewe, to the effect that "always vue at 100% to see sharpening".
Well, true enough, but doesn't answer why we get this misleading effect that you are asking about, Dean.

Hi Derek,

As to the why, the images at less than 100% zoom are resampled with a quick-and-dirty method for screen display which causes visual artifacts. Sharpening will translate differently to that sub-optimal resampling method and will produce its own artifacts, different ones at different zoom settings, so some zoom settings will look even worse than others while other percentages will produce more acceptable artifacts, but artifacts non the less.

Cheers,
Bart

[fdisilvestro]

I have done some tests and it seems to me that it is related to the previews been made on cached versions of the image.

By going to Edit->Preferences->Performance and setting the "Cache Levels" to 1 (Photoshop CC), then the sharpening is the same during the preview and after completed.

Notes: you have to restart PS after changing the configuration and depending on your HW it could make PS to run slow.

Regards

[DeanChriss]

My thanks to everyone for the replies.

I took some time to go through all of this again. In PS CC this issue is obvious enough to really grab my attention. For reasons unknown, using the same images and magnification settings in PS CS6 the difference between the preview and sharpened image is far less dramatic. The differences in CS6 are small enough that I have to look very closely as the change occurs to see them at all. "Cache Levels" = 1 does eliminate this but it also results in a much lower quality preview. I played with some of the other performance settings and they had no significant effect on the smart sharpening preview. I know sharpening at 100% is always WYSIWYG, but I've found that zooming down to 50%, or even 33%, gives decent guesstimate of the effect in print. It still does, but it has to be done after applying the filter. It's odd that, at least in my case, the CS6 preview is so much closer to the actual sharpened image when using all of the same performance settings, but I guess it'll have to remain a curiosity.

Thanks again,

[digitaldog]

Can't help, other than to half verify. My CC smart sharpen behaves like you describe. Less than 100% previews show more sharpening than actually gets applied.

Nothing really new here, been this way from day one with USM, you must view at 100% (1:1) for a proper preview of the sharpening (and unless you're sharpening for screen what you see can't be taken to the bank anyway).