Conventional wisdom is
that focus is the only thing you can't correct afterwards.
Conventional wisdom is wrong... sometimes. Sharpening is an effective
way of correcting minor discrepancies in the focus of a picture.
Here's a dilemma for you:
Sharpening creates noise and noise reduction creates a need for
sharpening. Hmm... It's not the dilemma it seems, because noise
reduction takes out less than sharpening puts in. It's about finding
a balance.
I talked about
Noiseware's sharpening tool before this chapter because it's such an
easy tool to use. Photoshop's sharpening tools (in the Filters menu)
are more versatile. There are four tools in the Sharpening menu:
Sharpen, Sharpen More, Sharpen Edges and Unsharp Mask. The one I tend
to stick with is Unsharp Mask. It's another of those effects where
you can see just what's happening as you play with the sliders. You
should be used to that by now so here's an example you may recall
from earlier.
When I used holly's
picture earlier to demonstrate hue/saturation adjustment, I'd already
done this. The picture on the left is really out of focus because of
the lousy lighting. The picture on the right is much sharper after
using the Unsharp Mask tool with a massive 200% increase, a radius of
5 pixels and a threshold of 3. I'm not even going to try to explain
those settings because it really is just a trial and error process
(for me).
The subsequent colour
alterations and noise reduction didn't spoil the picture's new-found
sharpness. Here are the original and final versions side by side.
Sharpening won't fix every out of focus image but, if you really want to keep a photograph and can't take it again, this is a way to improve what you're otherwise stuck with.
That
was an extreme example but the Unsharp Mask filter is very handy for
much more subtly lifting slightly blurred details.
I
said we'd come back to this dragonfly. These two pictures are before
and after I applied 50% Unsharp Mask. It's lifted the details,
especially the spots on the tail and (harder to see at this scale)
it's given the head much clearer definition.
Because this blog allows you to see bigger images, here's the final, noise filtered version.
Because this blog allows you to see bigger images, here's the final, noise filtered version.
I
use the Unsharp Mask sparingly because it can produce a lot of noise
and I still prefer the Noiseware sharpening option, but it has its
moments.