Hello! Welcome to my tutorial on how to sharpen photos using a Photoshop filter called Unsharp Mask.
The Unsharp Mask filter, also known to some as USM, is currently the Holy Grail of digitally sharpening photos during post-production. Forget sharpening your photos in Photoshop solely with Sharpen, Sharpen Edges, Smart Sharpen, and Sharpen More. Unsharp Mask is the way to go. Almost all photos (with the exception of those artsy purposely blurry ones) will benefit from the use of this filter. Seriously. Many-a-photographer consider the Unsharp Mask filter a staple in their post-production process.
WHY DO I NEED UNSHARP MASK?
Many first-time photographers out there wonder why their photos don’t come out as sharp as they want when they upload them to their computers. Unlike photos manually processed with film and a dark room, the lines and colors in photos taken with a digital camera are limited to a grid of pixels.
For example, we have a black diagonal line on a white background. In order for our eyes to see a smooth diagonal line on screen, the color has to gradually change from from black and white so that the hard edges of the pixels will not be noticeable. Hence, when you zoom into it, you can see grays in between the two colors. These gray pixels are what cause an image to look blurry.
Even if you’ve managed to perfectly focus your photos, the image on screen and the photo you’ll print will be slightly blurrier than what you are actually taking. So, this means that you almost always have to go through the process of sharpening your photos in Photoshop.
THE HOLY GRAIL: UNSHARP MASK
Alright, Let’s get to it! Here’s our sample photo with only the levels and size edited.
Tip: When working on your own photos, crop out unwanted parts of the image before adjusting and correcting anything else during post-production
Select the Unsharp Mask filter by going to FILTER > SHARPEN > UNSHARP MASK…
Tip: Zoom your photo at either 25%, 50%, or 100% when playing with the unsharp mask. Other zoom percentages have this weird anti-aliasing thing that doesn’t show the effects of Unsharp Mask accurately.
Now the sharpening magic begins! On the window, you’ll find 3 sliders: Amount, Radius, and Threshold. But first I’ll have to explain what each slider does, so you know what you’re doing.
AMOUNT is basically the strength of sharpening you want to apply to the image. When Photoshop sharpens images, it raises the contrast between light pixels and dark pixels–the light pixels get lighter and the dark pixels get darker. The higher you set the amount, the lighter the light pixels will be and the darker the dark pixels.
Raising the percentage too high can cause your photo to become very dotty and grainy.
RADIUS is the area of the pixels that will be sharpened on either side of the edge. It’s ideal to keep the radius low (close to 1) so that you can achieve a sharp, yet natural look for the image. A larger radius can be used for higher resolution images.
A too large radius can cause halos around the edges. While some purposely do it for their works, it causes your photo to look less natural and oversharpened.
THRESHOLD allows you to set how much difference there needs to be inbetween colors in order to be sharpened. This means that the higher the threshold, the higher contrast between colors there needs for it to be sharpened. Honestly, most people usually leave this at 0.
Tip: Check the preview box so you can see the effects on your image as you move the sliders
APPLYING THE UNSHARP MASK FILTER
So now that you understand what the sliders mean, it’s time to apply what you’ve learned!
When do you apply the Unsharp Mask filter? Some photographers like to enlarge their photos, apply the Unsharp Mask then shrink it back to it’s original size. While others believe that the Unsharp Mask should be applied last, when the final image size is reached. I personally like sharpening my photos while they’re still large, then shrinking them down to their final size.
How do you apply it?
- Go to FILTER > SHARPEN > UNSHARP MASK…
- Set the Amount to 100%, Radius to 1 (or 4 if you’re working on a higher resolution image), and Threshold to 0.
- Make sure the Preview box is checked.
- Move the radius slider up if you feel the image isn’t sharpened enough, and down if it’s over sharpened. As a rule of thumb, once you start to see halos forming around the edges in your picture, you should lower the radius.
- Adjust the Amount and Radius until you are satisfied.
- OPTIONAL: For images with a lot of noise, set the Threshold to at least 1 to reduce it.
- Press OK to apply the changes.
How much you sharpen your images all depends on personal preference. Some people like how striking the images appear after using Unsharp Mask, while others appreciate a more natural look. Try tinkering and playing around with the sliders until you get something you like!
For our example, I set the Amount to 137%, Radius to 0.5 pixels, and the Threshold to 0. Below, you can find a comparison of the picture quality before and after the Unsharp Mask filter is applied.
And that brings us to the end of our tutorial on how to sharpen your photos in Photoshop with the Unsharp Mask filter. I hope this tutorial has helped you improve your final photos!