By now, you probably know how to adjust simple properties in your images, like shadows, highlights,
and color.
But what if you had something with a less obvious issue; for example, a photo that looked
"soft," or maybe even a little grainy?
Fortunately, Photoshop comes with a number of filters that can help you with something
like this.
Today, I'm going to show you two of them: sharpening, and also a feature called noise
reduction.
Sharpening does exactly what you would think.
It can make your images sharper or clearer, so certain details are easier to see.
It can't fix photos that are blurry or out of focus, unfortunately—but if you have
an image that's a bit soft like this one, it can help.
Any time you're working with filters, it's a good idea to duplicate your layer first,
so you aren't making changes to the original.
Just right-click... choose Duplicate Layer from the menu... and then give it a name.
We'll type Sharpened to make it easy to tell the layers apart.
When you're done, go up to Filter on the menu bar... then mouse over the option that says
Sharpen.
Here you'll find a few different filters to choose from.
They'll all sharpen your image, but in different ways and to different degrees.
We're going to use the one called Unsharp Mask, which may sound a bit weird, but it's
exactly what we need.
It's very easy to use, and it'll let us customize the results.
As you can see, this filter gives you three different settings to work with: Amount, Radius,
and Threshold.
You'll see a preview in the document window as long as this box stays checked.
You also have a smaller preview that you can easily reposition.
Notice that when you hold this with your mouse, it toggles the preview on & off, which makes
it easy to compare the sharpened version to the original.
Now, any time you use sharpening, it's important not to make any extreme adjustments—you
can end up doing more harm than good.
That's being said, it's still OK to experiment, and nothing in Photoshop is permanent.
Why don't we get started with the Radius setting?
Radius controls the size of the details that are being sharpened, so generally, it's best
to set it to a lower value.
Too high, and the edges will start to look unnatural or exaggerated—this is called
a halo effect.
We recommend something between .3 and .5 for most images; you can even enter the exact
value here.
You could go a bit higher if you were working with a higher resolution photo.
The Amount setting controls the level of sharpness being added.
How much you need depends on several different things, including the image size, so it's
good to play around with this.
This time, if you go too low, the effect on the image may not be strong enough—see how
it still looks kind of soft?
In this case, I think I'm going to set the amount fairly high, somewhere between 180
and 190.
Finally, sharpening has a tendency to make image noise more visible.
Those are the tiny little flecks that can make your photo look grainy (you might even
see some in the background here).
Increasing the Threshold can help you reduce this, but you have to be careful—it can
cause your sharpening to become inconsistent.
Therefore, we recommend leaving this set to 0, unless the filter is creating lots of extra
noise for you.
So there we have it—I think we're done!
The difference is subtle, but it does make the image look a bit more crisp.
Once again, you can click & hold the preview to toggle it on or off.
When you're satisfied, go ahead and click OK.
Noise isn't just caused by sharpening—it can also appear in your image for other reasons;
for example, if the photo was taken in lower light.
Luckily, you can reduce this using a noise reduction filter.
Once again, you'll start by duplicating your layer, so you aren't making changes to the
original.
You can right-click like before, or just drag the layer down to the New Layer button.
Next, go ahead to the Filter menu... then mouse over the Noise option.
You'll want to choose the one that says Reduce Noise... and a dialog box will appear.
When you apply noise reduction, you're actually removing information from the image, so you
have to be careful when using this feature.
Removing too much noise can lead to blurriness or a loss of detail.
The key is to take it one setting at a time, and just keep adjusting them until you're
happy with the results.
So let's go ahead and get started.
First we have Strength, which basically controls how much noise reduction is being applied.
We recommend starting at the maximum value so you can see your adjustments more easily—but
you can always set it to something lower later if you need to.
Next we have Preserve Details, which controls how much of the original image is left untouched.
You might want to play with this one a bit while you keep an eye on the preview.
Choose a setting that's too high, and you'll actually cancel the effects of the filter...
but if you go too low, you'll start to lose detail.
We're going to shoot for something less extreme, maybe around 5 or 10%.
This keeps some of the detail, but also gets rid of a lot of the noise.
Sometimes, noise will look like small patches of individual colors—the word for this is
color noise.
You can mitigate the effect by increasing the Reduce Color Noise setting.
Just be careful not to increase it too much, or, depending on the image, the colors might
start to bleed together.
For most images, we recommend a lower setting; I think 40% or 50% should do it for this one.
Finally, reducing noise can also cause the image to lose some sharpness.
You can add the sharpness back using the Sharpen Details setting.
Just like Preserve Details, increasing this too much can cancel the effects of the filter,
so you generally want to aim lower.
In this example, we're going to set it to about 10%, which should sharpen it just enough
to make a difference.
Keep in mind, you can use the same click & hold method to compare the filtered version to
the original.
If you look closely, you'll see that the difference is pretty slight, but we did manage to reduce
some of the noise.
As you can see, there are lots of minor problems that you may not have realized you can fix
in Photoshop.
Now you know how to sharpen your images and reduce image noise, using two easy-to-use
filters.