Odd behaviour of unsharp mask

[Stuart444]

When using unsharp mask, viewing the "before" and "after" alongside each other, the "after" responds to changing the control sliders as I'd expect, but when I click "Apply", the image then shown is distinctly less sharpened than the "after" picture, it's some way between the previous two. See example attached.

 

Using the Clarity sharpen, I suspect the same is happening, although the final result is much closer to the "after" preview.

 

Any suggestions? Generally I try to sharpen a "bit too much" on the screen when preparing for a large print, but I'm having to take it to an extreme with this issue.

 

Unsharp mask problem.pdf

[James Ritson]

Stuart, are you previewing at 100% or larger when using these filters? If you're at a lower zoom level, Photo may be using a mipmapped (lower resolution) version of the image for performance reasons - therefore the preview will look different from the final result that is applied to the full resolution image.

 

There shouldn't be a huge difference, however. Could you perhaps try the same filters at 1:1 zoom and see if this solves the issue? (And if not, please let us know!)

 

Thanks,

James

[Stuart444]

Hi James,

 

Thanks for your reply. I think you hit the nail on the head. Generally I've been trying to follow this chap's advice..... http://ronbigelow.com/articles/sharpen2/sharpen2.htm... and he says 100% to set the radius and 50% to finalise the settings to give the best overall view, is best. I don't recall what zoom level I was using for the above, but I suspect it was less. I've taken the orf file again, developed it unchanged, then zoomed to 50% by eye (could we have a 50% zoom setting please? - how about Ctrl+9 as this is the same as Ctrl+1) and got better results (near the bottom of this updated file). This looks much better, the "after" and the result are very close to my eyes.

Unsharp mask problem rev 1.pdf

[R C-R]

The Zoom tool (magnifying glass icon) has a numeric Zoom setting & slider in the Context toolbar, as does the Navigator Studio panel. Both have 'snap to' slider settings including 50%, among others.

[Stuart444]

Thanks R C-R, I've been using View / Zoom which doesn't have this feature. I can find the Navigator zoom slider, I hadn't noticed it before, and that's useful if not quite as quick as Ctrl+. I hadn't noticed the magnifying glass at the bottom of the tools bar either - similar comment. But much better than guessing.