Pro Sharpening

[Brownbear]

Scott Kelby's Digital Photography book provides the following recommendations for Pro Sharpening

People - Amount 150%, Radius 1 Threshold 10

Cityscapes - urban photography or travel - Amount 65%, Radius 3 Threshold 2

Everyday use - Amount 85%, Radius 1 Threshold 4

I am trying to understand the logic behind the theory? How does one determine with ease (simple common sense) how much to apply for each?

From the tutorials on Cambridge

https://www.cambridgeincolour.com/tu...sharp-mask.htm

Amount is usually listed as a percentage, and controls the magnitude of each overshoot. This can also be thought of as how much contrast is added at the edges. Higher for cityscapes?

Radius controls the amount to blur the original for creating the mask, shown by "blurred copy" in the TEXT illustration above. This affects the size of the edges you wish to enhance, so a smaller radius enhances smaller-scale detail. Guessing higher for cityscapes and lower for portraits?

Threshold sets the minimum brightness change that will be sharpened. This is equivalent to clipping off the darkest non-black pixel levels in the unsharp mask. The threshold setting can be used to sharpen pronounced edges, while leaving subtle edges untouched. This is especially useful to avoid amplifying noise, or to sharpen an eye lash without also roughening skin texture. Higher for portraits?

Thank you.

[Chris]

I am no expert by any means, I recently downloaded Matt Kloskowski Lightroom print sharpening pre-sets and they are not close to those quoted from Scott Kelby's book, I have tried them a couple of times but not convinced.

I have just started using NIK shapener which to me feels easier and more intuitive but I am not sure as to which is the best approach.

[Geoff F]

The figures which you quote, Christina, aren't far different to what I use on a daily basis.

I suppose my average Unsharp Mask settings would be 100 to 150% and 1 radius where there is fine detail; and 2 radius for greater effect on a 'plainer' surface. Some reductions might be needed at times.

Threshold set to the lowest amount that avoids excessive noise. Usually 2 or 3.

But that is for the main sharpen.

After resizing for web use, something around 60% 0.4 radius and 1 threshold usually works OK for me.

Sometimes, if I am getting problems but need a reasonable amount of sharpening, I will create a duplicate layer and set the blend mode to Luminosity. Sharpen the layer. Merge with the background after sharpening.

Using 150% does sound a bit high for 'People'. But do we mean general overall shots or close portraits? And having a fairly high threshold would mean that higher contrast areas such as mouth and eyes receive the most sharpening while plain skin is relatively unaffected.

But everybody seems to prefer slightly different settings so I think it is mostly a case of trying different methods on the same image then deciding which option suits you.

But remember that prints often look different to on screen images. Sometimes I have screen views which look decidedly poor; but they print fine. Usually, this is chiefly a case of the screen view not being seen at the optimum image setting.

[Macmahon]

Christina
I don't think general 'rules' on how much sharpening to apply make a lot of sense. To me each image needs its own judgement. It is probably true that for landscape/cityscape where there may be fine detail you'd want to be using a smaller radius, and for portraits where you may want to soften, say, skin pores, you'd want to use a bigger radius, but the amounts are very much a question of taste. The only other generalisation I adhere to is that nothing ruins a photo quicker than overdone sharpening.
However, FWIW, here is an article that goes into the background to your questions. Hope it's helpful.
Cheers
Tim

[Brownbear]

Thank you Geoff and Tim. Your explanations are very helpful. Tim, that is a great article that I will have to read a few times...sharpening is far more complex than I thought it was.

Geoff, I don't understand why it is suggested that photos need to be sharpened after being re-sized for web site presentation? The photos we use on the web are smaller

[Colin Southern]

Hi Christina,

I've posted about sharpening a bit in the past ... you might find these helpful ...

When/How to Best Sharpen a Digital Photograph

Sharpening and Noise Reduction Sequence

[Brownbear]

Hi Christina,

I've posted about sharpening a bit in the past ... you might find these helpful ...

When/How to Best Sharpen a Digital Photograph

Sharpening and Noise Reduction Sequence

Thank you Colin, very informative and helpful

[Geoff F]

When doing a substantial downsize, Christina, you are removing a lot of pixels and hoping those which remain will be 'correctly positioned' but in reality this can cause a bit of softness.

So a slight sharpen afterwards just helps to crisp things up a little. Sometimes it isn't a problem but with other images the softness is noticeable. And particularly if you leave your original full sized photos a little on the 'safe side' of sharpening instead of risking over sharpening.

The general recommendation is to use Bicubic Sharpener setting when downsizing (if you have suitable software). But I have found this auto sharpening during downsize to be somewhat variable and I often don't like the results.

So I resize first then manually apply a little sharpen afterwards to suit each individual image. Although 60 to 80% and 0.5 or 0.4 radius would be average. But some photos, particularly when the resize isn't excessive, don't need anything extra.

[Brownbear]

Thank you Geoff. I noted that in Colin's link, but your explanation adds clarity, and I will try it.

[Shadowman]

In the book I have "The Photoshop Elements 8 Book" he mentions sharpening for particular portraits, infant, female, or soft and subtle settings, so you have to apply each to your own taste and the particular subject. Also, the settings he suggests are his preference, you might like something a bit more aggressive.

[Brownbear]

Thank you.