Sharpening after resizing?

[Lee Costa]

I’ve been reading about how to properly resize an image, and almost everything I’ve come across mentions that sharpening should be done after resizing. The issue I have is that once I resize my images to my preferred size (1920 on the longest side), I have trouble assessing how much sharpening has been applied when using Smart or Unsharp since the image is now smaller. I’ve also noticed that when resizing an image using the Bicubic Sharper (reduction) resample, the image appears sharper right away, which makes additional sharpening easier since only a little is needed.

What is the recommended workflow? For some context, I am shooting RAW and importing into Lightroom for editing. I also enjoy sharpening in Lightroom but don't like how you can only resize on export and is forced to apply a sharpening preset which removes any fine tuning.

Thank you.

[Ares Hovhannesyan]

For RAW formats I recemoend to use Camera Raw features. Did you try?

[Lee Costa]

I did not. How would I implement it in my workflow since I do most of my edits in Lightroom? I am not at all familiar with Camera Raw. 

[D Fosse]

Personally I avoid bicubic sharper and bicubic automatic. I feel they oversharpen and introduce too much edge artifacts. (Note that bicubic automatic just means bicubic sharper for downsampling, and bicubic smoother for upsampling).

Bicubic smoother has very little sharpening built in, which lets you apply and fine-tune your own sharpening after the resizing.

My preferred sharpening tool is the ACR filter. Here you can control edge halos much better than with any other method. There is no general rule for how much - except this one: Always view at 100% when assessing sharpness! 100% means that one image pixel is represented by exactly one physical screen pixel. It's the only way to see the pixel structure accurately.

If in doubt, err on the cautious side. Undersharpening is preferable to oversharpening. I mostly aim for "crisp" rather than "sharp".

Edit - to be clear, that's the Camera Raw Filter in the Photoshop filter menu. You can still process your raw files in Lightroom Classic and open through "Edit in Photoshop".

[Lee Costa]

Thank you for the informative reply. I will try the smoother instead and check my results.

And for the sharpening; before or after resizing?

[D Fosse]

Oh, definitely after. That's the whole point. The resampling will in itself soften the image, that's why some of the algorithms have sharpening built in. But I think they overdo it - and I'm not the only one thinking that.

As for amount, sharpening is always an equation with several unknowns. So it's impossible to give a stock answer. It depends on image content, but it also depends a lot on output medium. Printing on glossy paper requires slightly less than matte/uncoated paper, for instance. Ink diffuses a bit in the paper, so you may need slight edge halos to compensate.

For web images, on the other hand, there is often so much automatic scaling these days, with responsive sites and whatnot, that sharpening will often be negated in the browser anyway.

Just prepare it so that it looks good on your screen, at 100%, and you'll be fine.

[Lee Costa]

Ha, my apologies for the oversight! Obviously after as you suggested the resampling above.

>For web images, on the other hand, there is often so much automatic scaling these days, with responsive sites and whatnot, that sharpening will often be negated in the browser anyway.

That's a great point.

And what's the go to filter nowdays? Smart or Unsharp?

[Per Berntsen]

It's not clear if you're already doing this, but you should sharpen the original in Develop in Lightroom (capture sharpening), which is exactly the same sharpening as in Camera Raw or the Camera Raw filter.

Do this at 100% - the image should look sharp, but not too sharp. If in doubt, sharpen less.

Then do output sharpening on export. Since you export to 1920 px, I assume that this is for screen viewing.

Choose Sharpen for screen, try Low for amount first. If it's not enough, try Standard. High is rarely needed.

Make sure to view the exported image at 100% to assess sharpness.

Lightroom's capture sharpening and output sharpening for screen are both excellent.

[Lee Costa]

This has always been my workflow, to be honest, but recently I started going down a rabbit hole of attempting sharpening in Photoshop.

It's not clear if you're already doing this, but you should sharpen the original in Develop in Lightroom (capture sharpening), which is exactly the same sharpening as in Camera Raw or the Camera Raw filter.

By default, Lightroom appears to apply some basic sharpening to all my photos on import (around 40). Some research suggests this is the default behavior for Nikon (correct me if I’m wrong). From there, I usually edit to my liking, and once I’m satisfied, I start adjusting the sharpness by first resetting all the sliders to zero. I use ALT on my Mac to preview the sharpening settings as I apply them.

Then do output sharpening on export. Since you export to 1920 px, I assume that this is for screen viewing.
Choose Sharpen for screen, try Low for amount first. If it's not enough, try Standard. High is rarely needed.
Make sure to view the exported image at 100% to assess sharpness.

It’s indeed for screen viewing, and I’ve always used the Standard amount for output sharpening, which I’ve been pretty satisfied with. However, I may need to rethink sharpening in Photoshop since, no matter what I do, my results in Lightroom seem better.

[Per Berntsen · Accepted solution]

If you have a Nikon Z camera, sharpening settings in the camera will carry over to Lightroom, they are written in XMP which Lightroom understands and honors. I have a Z 7, and the first files I imported had sharpness set to 40 and radius to 2, leading to gross oversharpening.

I prefer a low radius and a high detail setting, so I use Sharpening 40 - Radius 0.5 - Detail 100, and use Masking for noisy images to prevent sharpening of noise in flat areas.

You can create a preset of your preferred Develop settings on import, and set that to be the default for all images from a particular camera in Preferences > Presets. See https://helpx.adobe.com/lightroom-classic/help/raw-defaults.html

It sounds like a good idea to rethink sharpening in Photoshop, Lightroom does a very good job with it.

And you're creating a lot of extra work for yourself by resizing and sharpening in Photoshop.

Unsharp Mask is quite a crude tool, and ancient technology. I remember using it in Photoshop 4 around 1997.
Smart sharpen is better, but I haven't used it for ages. I'm not so keen on Lightroom's output sharpening for print (it tends to create halos), so I use Topaz Sharpen AI for that.

Remember to always view the image at 100% when applying sharpening and evaluating sharpness. (use 200% if you have a 4k or higher monitor)

This is the only view that gives you a true impression of the image – one image pixel is represented by one screen pixel.

Any other view will be inaccurate and misleading because the image has been scaled.

[Lee Costa]

I do have a Z camera (Z6). I will adjust my settings to mimic yours as a trial and adjust from there. I will also create a preset per your instructions.

Thanks for all the helpful information.

[Stephen Marsh]

@Lee Costa 

You may wish to compare removing all sharpening, including capture sharpening in Lr, before upscaling and applying sharpening vs. capture sharpening + upscaling and applying sharpening.

[NB, colourmanagement]

@Lee Costa "I’ve been reading about how to properly resize an image, and almost everything I’ve come across mentions that sharpening should be done after resizing. The issue I have is that once I resize my images to my preferred size (1920 on the longest side), I have trouble assessing how much sharpening has been applied when using Smart or Unsharp since the image is now smaller."

Always sharpening is best done after setting image size. Because sharpening is size-dependent. I would never resize after applying the final sharpening. Yes, the image is smaller in your example - so be sure to view it at 100% and sharpen it til it looks right to you. That is how others will see it too. If sharpening for print you'll learn by doing print tests. 

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google "neil barstow colourmanagement" for lots of free articles on colour management
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