Digital Darkroom; Basic Sharpening Photoshop

The Digital Darkroom is a series of posts aimed at beginners and those interested in Digital Photography and Editing. In previous weeks we have looked at basic adjustments, curves, editing colour with the HSL/Color panels, black and white toning, split toning, local adjustments, sharpening, noise reduction and Lens Correction and Camera Calibration in Lightroom and Adobe Camera Raw. Moving into Photoshop we have looked at the program’s layout,basic adjustments to light, basic adjustments to colour, basic black and white adjustments and this week sharpening with Unsharp Mask, Smart Sharpen and Shake Reduction Filter.
If you wish to check out previous posts in the series you can do here.

As we covered in with capture sharpening in Lightroom; If something isn’t in focus when the picture is taken, it cannot be made sharp through sharpening. It is possible to recover details from slight lens blur; the bigger the blur however, increases the number of artefacts created through the sharpening process.
Sharpening an image is all about emphasising the sharp in focus details, which are made soft by the capturing process or will be made soft by the printing process. All images will need some sharpening, Jpeg’s don’t require capture sharpening because this is applied in camera but may need creative and output sharpening. Raw captures will need all three in some shape of form. However if you apply capture sharpening to your raw files in Lightroom or Adobe Camera Raw you don’t need to  apply capture sharpening again, but you can apply creative and output sharpening in Photoshop.

In Photoshop under filters- sharpen there are a few sharpening filters although only three are interesting enough to use. Sharpen, sharpen edges and sharpen more are all auto filters that you have no control over and cannot be sure how much sharpening is being applied to an image.
Smart Sharpen, Unsharp Mask and Shake Reduction (CS6+CC only) are the main sharpening filters.

Sharpening-DialogueUnsharp Mask is a really powerful sharpening tool that gives you a lot of control.

Amount – Lets you control the strength of the sharpening. The amount of strength is different from image to image and camera to camera but somewhere between 50-200% is usually pretty good.
Radius – Radius controls the intensity of the sharpening by setting the width of the sharpened edges. For capture sharpening a radius of 0.4-1 should be sufficient.
Threshold – Threshold controls which edges will be sharpened by setting the minimum difference between light and dark pixels that can be called an edge. A threshold of three would require a very small difference between the pixels tones compared to 100 which would need a much bigger difference. For those used to using Lightroom this slider can be equated to Mask when sharpening.

This Picture of a park scene is a high frequency image with lots of details. I first set the radius to find the right amount of intensity for the sharpening and then increase strength until I artefacts coming in. Lastly I use threshold to minimize the amount of artefacts that were appearing.

 

Smart Sharpen is a great sharpening tool and is really good at edge detection. Due to this I find that I use smart sharpen for selective sharpening works really well.
In the basic mode there are two sliders;
smart-sharpen
Amount ­– which controls the strength of the sharpening.
Radius – which controls how much you are sharpening.
There are also three removal options that allow you to remove some blurring;
Gaussian ­– this removes the same softness as normal sharping would.
Lens Blur – which counteracts slight lens blurring.
Motion Blur –which can help sharpen slight motion blur from a picture.

Due to these removal tools you can apply sharpening and some lens correction at the same time. This will not however remove all of these blurs just tighten up the sharpness around softer blurring.
The real control however takes place in Advanced Sharpening, where you can tailor the sharpening to the image and damper the effect in certain tonal areas. In advanced sharpening you have a shadows and highlights tab and in both there is;
Fade – selectively reduce the amount of sharpening in the tonal area.
Tonal Width  – sets the width of the tonal area that Fade is applied to.
Radius – allows you to control the area width of the smart sharpening.

Using smart sharpen with the advanced options allows you to have a large amount of sharpening yet reduced artefacts in tonal areas that may appear. For example detail is in the highlights and needs to be sharpened yet artefacts that appear in the shadows. Clicking for the shadow and highlight options lets you curtail the artefacts in the shadows while preserving the sharpening of details in the highlights.

smart-sharpen-with-large

This image of the fish in an aquarium needed sharpening, because I was shot the picture through glass. Shot at 6400 ISO I needed to be careful not to emphasise the noise. I sharpened first with the basic Smart sharpen settings then moved on to Shadow and Highlight. Most of the detail is in the darker tones so I applied a higher fade on the highlights to curtail the sharpening. Within the shadows though the darker shadows had no detail that I wanted to preserve so I tried to target this to fade out the sharpening there and reduce some artefacts

Shake Reduction

The Shake reduction Filter is one that I have found really great when; you have pushed the exposure a little longer than you lens and IS can take creating a slight blur or when doing Macro work with the slight movement vibration through the lens when I am really close up softening the image.

I tick artefact suppression to reduce noise that can be caused by sharpening. I also set the source noise to auto as well.
Blur Trace Bounds Sets how much blur is being reduced.
Smoothing and artefact suppression helps to reduce edge noise.
Artifact Suppression – eliminates noise artifacts in medium and low contrast areas. Having this set to 0 will make the image look sharper but with more artifacts (which we don’t want).
Smoothing – is a noise reduction slider. This will make the image look cleaner, yet less sharp.

With advanced mode ticked you can use the blur estimation tool to select an area to be measured for the reduction. You can add multiple estimation regions to get the best measurement possible.
You can also use the Blur Direction tool to reduce slight motion blurs due to camera shake.

shake-reduction

With this tool I generally will let Photoshop do most of the work and tweak some sliders. This tool is powerful and depending on your computer can take a few moments to show you a coarse preview. Any tweaking of the preview will result in some more waiting. The preview does not represent fully the final effect but will give you a good idea of how much the image has been sharpened.

Which to use

This is the question. I wouldn’t use all of them together with strong adjustments since this will create a lot of artifacts in the image.
I  use Shake Reduction on images I know I got sharp but due to shutter speed or my own had the image is a little soft. I will apply this adjustment before any other editing steps and as capture sharpening.
Generally I will use Unsharp mask for capture sharpening if I haven’t had to use the shake reduction filter and Smart sharpen for more specific sharpening. I apply capture sharpening before any other adjustments in Photoshop, and creative sharpening after colour and light adjustments.
The key however is to get an image which is defined without grainy artifacts appearing and distracting the viewer’s eye. It is always best to sharpen with the image zoomed in at 100% to see the effect at pixel level.

In a future post I will cover more advanced sharpening methods in Photoshop. Next week I will be looking at noise reduction.

If you have any questions or comments please use the comment box below, all are welcome as this series is designed to help people learn how to use Photoshop and Lightroom.

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10 thoughts on “Digital Darkroom; Basic Sharpening Photoshop

  1. Ben, I learned about shake reduction from a post you did for ABFriday and it saved an image for me! I’m delighted you went into more depth here about the sliders and what they mean, as I never figured out what they meant. Now I’ll be able to use it in an even more powerful way. Thanks, too, for spelling out your sharpening workflow. Incredibly helpful. I really must make it a point to view all of your tutorials on Photoshop!

  2. Thanks Ben, a brilliant tutorial … as other’s have mentioned the what -to- do with sliders I can see will be really helpful . The balance I’ve found for me a bit hit and miss re noise and sharpness . I see your are tackling the noise issue next week 🙂

    • As a preview for next week I do reduce noise before sharpening because noise reduction also softens an image but in a way you do need noise sometimes to help show details. The amount of noise reduction is important.
      Hope you will find next week’s post as interesting as this weeks.

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