How do I get sharp images?

[mmeyer]

I am hoping someone can give me some help with sharpening images. I know that most digital images need some sharpening and I do that but I'm just winging it most of the time. Can someone give me/us some guidelines for sharpening.

Thanks

[Steve Foss]

Oh well, I guess I asked for it!

Here goes.

First, sharp images begin at capture because there's only so much that software can do to sharpen a soft image before the image starts to fall apart. A lot of what follows are tips on getting sharp captures so there's less heavy lifting during post-processing. Some of these are pretty basic but some are not, and they reflect my actual experiences out in the field.

Stabilization/technique. Even a fast shutter speed is no exchange for rock-solid technique. A monopod or tripod is a valuable tool in most situations. The stronger the telephoto (focual length) the more hand/camera shake plays a role, and the more some type of stabilization is needed. An image stabilized lens can be a Godsend, but there are plenty of times even IS won't help you capture the sharpest image without some help (like a monopod.)

Zoom vs prime lenses. Most of us know that zooms are inherently a bit softer than prime (fixed focal length) lenses. The best zooms aren't much softer but usually are just a bit less sharp. To ensure a sharper image with a zoom (any lens, really, though with zooms it can be more critical), it's good to stop down from max aperture, for example from f5.6 to f8. In doing so you lose another stop of shutter speed, which is why stabilization and technique can be so important.

Focus point. Depth of focus is razor thin with subjects close to the camera, so pay particular attention to your focus point. At f5.6 or f8, DOF six feet away using a 300 or 400mm lens might be less than an inch, so if you lock focus on the wingbar of a perched bird at that distance and the bird is facing/slanted slightly away or toward you, the head/eye probably will be soft because it's missed the prime DOF range. Best to lock focus on the eye, then recompose quickly to make the capture.

Exposure. Not a primary consideration, but an important secondary one. A bird shot against a pale sky with no exposure compensation used will almost always be underexposed. While that does not inherently compromise sharpness, it does in effect because in brightening up the underexposed subject, digital noise makes its inevitable appearance, and that compromises how much sharpening you can do in post processing. The more sharpening, the more noise is accentuated. When Ken and I shot the eagles on Snowbank, we immediately, as we were putting the cameras up to our eyes, spun the dial to overexpose from one full stop to 1 1/3 stop, because we know that the meter would want to turn that pale sky a darker, mid-range gray, and that would have badly underexposed the bird's dark feathers. An even better example is a white bird against a pale sky or a white weasel on snow. If you let the meter tackle it, it'll render the scene a mid-range gray and will be underexposed, so when the image is brightened up in pp, noise appears. An exposure compensation of about +2 is usually needed in those situations to render whites white (instead of gray) without blowing them out.

If you've been careful to do all the things mentioned above, you'll have the sharpest possible image before sitting down at the computer.

Post processing. Most post-processing software out there today has very sophisticated sharpening tools. In Photoshop, unsharp mask is the most commonly used, though I employ smart sharpen often. If the subject is a bird or animal or person and I want to sharpen it, I usually lasso it and sharpen the subject alone so the background doesn't get sharper. My typical settings on either unsharp mask or smart sharpen are a radius of .7, with the percentage varying from 100 to 300 percent in most cases. It just depends, and each image is a bit different so you'll want to experiment with different radius and percentage settings. When I lasso a subject for sharpening, I generally lasso just inside the outer edge of the subject so the sharpening doesn't produce an edge halo.

For landscapes or images with lots of small detail, watch carefully when you sharpen the whole image to avoid lots of halos, which can make the image look grainy and overcontrasty.

If you have a Save for Web feature in your software, go ahead and sharpen the image so it appears just slightly oversharpened on your monitor. Saving for Web softens them just a bit in my experience. Also, LCD monitors seem to show images more sharply than the older CRTs.

This is something that demands plenty of trial and error, and when posting images online, simply ask folks to comment on whether they look oversharpened.

That's a start . . . I know every photographer may have slightly different sharpening regimens, so feel free anyone to chime in on how you do things differently.

[yakfisher]

Thanks for asking Mike and thanks for the response Steve.

[MN Shutterbug]

Great tutorial, Steve. I'm going to email this to my neighbor who is having some problems with getting sharp images. I know she can do it, because I've seen a few that she has shot. However, I guess her keep rate is quite low.

[mmeyer]

Thanks Steve. I appreciate you taking the time to help me/us out with this stuff!

[MARINERMAGNUM]

If it's any consolation Mike,your images look sharp to me!

[Dbl]

I will just give you some basic numbers since Steve gave you such great explanation on the other factors.

I also use smart sharpen a fair amount and use Noise Ninja as well. Smart sharpen I use a 85, 1.3, Gaussian blur.

I use Scott Kelby's numbers for most of my general sharpening with unsharp mask.

General sharpening - 85, 1, 4. This is a setting that can be used more than once. This is the one I use most often.

Hard sharpen - 65, 4, 3. This is for soft images and only used once. I can often rescue a slightly soft image using this setting.

Haze contrast reduction - 20, 50, 0. Great for slightly hazy photos or where you want some "pop" to an image.

These are the sharpening settings I use 99% of the time. Experiment with some of these settings and see if any work for you.

[mmeyer]

MM thanks, I think they are ok too but some of the stuff I see on here and elsewhere online is just amazingly sharp. I imagine a lot of it is the glass which I'm lacking in a little but anything I can do to improve what I have is welcome.

Dan, thanks for that help. I'll be filing those numbers away to use in the future. That's great info!

[Steve Foss]

Whoops, forgot to supply the third number for my typical sharpening. My threshold is usually at 0.