Digital SLR photography — Getting sharper pictures

You don’t need to see every strand on every feather in a bird photo to make it a nice shot (see the sample detail from this photo in the image below). In fact I’d say other factors are much more important. But it’s nice to get things sharp when you want it. The bird is a Welcome Swallow.

Equipment

This is the first thing people think of, but it’s usually not the culprit. Most camera gear these days works like it should. That’s not to say quality control is always perfect. I’ve experienced the frustrations of a camera that focused unreliably. In my case, the problems disappeared after a firmware update.

So I don’t want to suggest that equipment is never to blame. But in the vast majority of cases a soft photo is the result of one or more of the things I describe below.

Fast-moving, nervous tiny birds darting about in very weak light, like this Silvereye, can represent a huge challenge for photographers. Yet it’s even possible to consistently get tack-sharp photos of these reluctant subjects if you understand the potential problems and know how to work around them. In this case, I used a strong flash, which put enough light into the scene to make things easier for the camera.

Image stabilization allows for hand-held photography at slower shutter speeds.

Camera shake

In a perfect world our hands would be as steady as tripods. But they’re not. Which is why we invented tripods. An awful lot of soft shots are in fact the result of tiny amounts of camera shake, especially when your’re working at maximum zoom (a long lens).

What do about it

• Find a way to keep things still. When I take a shot my elbows are leaning against my chest and I hold my breath a little as I squeeze the shutter button. And I keep that stance until the shutter has properly closed again. If there’s something solid around I might lean against it. Or stand with feet apart and knees slightly bent, for more stability.
• Kneeling down and using your elbow on one knee like a sort of tripod is another way of minimising camera jiggle. Using a tripod, a monopod, or resting your camera in a small bean bag will obviously help too. Otherwise, you can look for something solid to sit your camera on.
• Never jab or tap the shutter button. Instead you should squeeze it or roll your finger onto it. Jabbing that button is going to cause vibration in the camera that will almost guarantee a blurred shot.
• Use the image stabilization system if you have one. Whether it be called Image Stabilization (Canon), Vibration Reduction (Nikon), Optical Stabilization (Sigma) or whatever, it helps reduce the blur caused by the camera shake that comes from our unsteady hands. If your camera gear does have it then it can be worth the effort to read up about it in your manual. That’s because it often needs different settings for things like panning or when using a tripod.

A long telephoto lens can bring you ‘closer’ to small wildlife like this Restless Flycatcher, but it also brings a need to be much more vigilant against camera shake.

Telephoto lenses

The longer your telephoto lens, the more noticeable camera shake becomes.

What to do about it

Here’s a rough rule to keep in mind when you’re working hand-held: use your focal length number as a minimum shutter speed number. In other words, if you’re using a 200mm lens hand-held then you shouldn’t have a shutter speed any slower than 200th second.

Moving subject

Even if your camera’s on a rock-solid tripod, that’s not going to stop motion blur if your subject is moving. For example, a car driving past at 60 kph will travel about 27cm during a 60th second exposure. That’s 27cm of motion blur. And some types of birds are forever jerking their heads backwards and forwards when they walk.

What to do about it

• Panning (following the action by keeping the lens pointed at the moving object) will reduce the amount of motion blur in the subject. And it will help contrast the subject from its background by blurring the background
• Selecting a very fast shutter speed will also help to reduce motion blur. For example, I often use a shutter speed of between 1,000th and 2,000th second, for small, twitchy birds.

The shutter speed for this photo of a swooping Masked Lapwing was 800th second. I could have perhaps gone a bit faster but the light wasn’t all that strong. Also, I was happy to allow a little bit of motion blur around the wings to emphasise the sense of movement.

A Water Dragon turns its head. I admit this is an extreme example of this type of motion blur but I include it for two reasons — one: because head movements in animals result in an awful lot of blurred shots, and two: I thought it was funny.

This Brush Turkey chick was constantly moving on the floor of a dark rainforest. Getting a sharp image without the use of a flash can be difficult under those circumstances.

Shutter speed too fast

Huh? Isn’t a fast shutter speed supposed to make things sharper? Not always. In low light a fast shutter speed can reduce image quality. You see, in low light, a shutter speed that is too fast is going to do two things:

• It’s going to force the aperture to open up to its maximum. That will reduce depth of field, which means you might not get all the important parts of the scene in focus
• And it’s going to encourage your camera to reach into its high ISO levels. When that happens your images can start speckling with noise.

What do do about it

If you’re working in weak light then resist the urge to use extremely fast shutter speeds. And you should also think about locking your camera’s ISO at a setting no higher than what you know it can realistically handle.

Not enough light

In the previous section I talked about one of the difficulties of working in weak light. I’m talking about losing depth of field and noise getting into your photos.

Seriously, you’d be surprised how often I see photos taken in weak light that turn out to be soft, which is why I’m making a big deal about the subject here.

What can you do about it?

If you know that weak light is your problem then you’re just going to have to find a way to get more light into your lens. That might mean using a flash powerful enough to reach your telephoto’s subject, or it might mean mounting your camera on a tripod and using a slower exposure (and hope your subject doesn’t move too quickly for your slow shutter speed).

The photo of the Rufous Fantail above left was taken without a flash, which forced the camera to slow the shutter speed down to 1/32 second. Not nearly fast enough for such a fast-moving bird, and not fast enough for working hand-held with the 400mm lens I was using either. The photo at right was taken in the same place with the same lens, but this time using a flash.

Tripod issues

I once heard it said that there were two types of tripods: the ones that are easy to carry, and the good ones.

A cheap, lightweight tripod will allow even the slightest breeze to wobble your camera enough to get camera-shake blur. So if you’re buying a tripod, consider getting a good one. Think of it as an investment because our tripods tend to last much longer than our cameras.

Incorrect use of a tripod

Here’s something you might not have realised: as you gradually extend the legs of your tripod you should always use the top extensions first. Because the top extensions are thicker than the lower ones. Thicker legs means a more stable tripod. Ideally, the lower, thinner, leg extensions should only be used in calm conditions. So if it’s windy, then think about not extending your tripod all the way.

Old (left) and modern (right) versions of a cable release.

Not using a cable release

Even if you’re using a good, solid tripod, you can still get camera shake from the way you press your shutter button. Even a careful squeeze of your shutter button can be enough to cause the kind of camera movement that’s noticeable if you’re using a long lens or doing macro photography.

What to do about it

If you really need to keep the camera still then you should think about using a cable release.

A cable release is a cord with a button on the end. You connect one end to your camera and the other end with the button goes in your hand. When you press the button, the vibrations don’t make it all the way down the cable and so the camera doesn’t shake.

If you don’t have a cable release, then think about using a delayed exposure. For example, if your camera fires 10 seconds after you pressed the shutter button, then it would have had plenty of time to stop vibrating.

Depth of field, or perhaps I should say, not enough depth of field, can be a big problem when photographing very small creatures. I wanted the entire face of this jumping spider to be in focus, so I took a series of shots focusing at different depths and merged them all into the one shot in a process called stacking.

Not enough depth of field

Depth of field is the amount of distance between the closest and most far-away things in focus. If you don’t have enough depth of field then you won’t be able to get enough of your subject in focus.

What to do about it

You control depth of field with your aperture setting. If you choose a smaller aperture (bigger f-number) then your depth of field will increase. When photographing people or wildlife at a distance then about f/8 is usually sufficient to get enough of the subject looking sharp. f/11 will make even more of the subject in focus.

But don’t push that aperture too far. Really small apertures, like f/32 for example, cause problems of their own. Also, as a general rule, depth of field issues will not be so noticeable at shorter focal lengths.

Another trick you can use it to take two or more photos of the same scene, focused at different distances. Then merge all the sharpest bits from the shots together on your computer later. That process is called stacking.

I talk more about depth of field on this page and you can read that to fill in a whole bunch of gaps in understanding all this stuff.

Aperture too small (f-number too big)

100% crops of the same photo taken at f/5 and f/32.

Even though some of my lenses allow me to choose apertures as tiny as f/32, I don’t like using anything smaller than f/16. And even that setting is something I only use when I really need a heap of depth of field.

You see, at those really small apertures (big f-numbers), some unpleasant physics start happening with the way light works. To cut a long story short: tiny apertures cause diffraction, and that can make the entire image go slightly fuzzy. Compare the side-by-side samples at right to get an idea.

What to do about it

Try not to go beyond about f/16. Or better still, if you’re trying to get reasonable amounts of depth of field then f/8 to f/11 is probably a safer range of apertures to use.

Combinations of factors

If you can’t narrow down any one cause for soft photos then quite often it might be a combination of things happening. This is especially likely in weak light, when high ISO, low depth of field and slow shutter speeds (which increase motion blur and camera- shake blur) all combine to produce a soft photo.

What to do about it

Think about every setting that went into taking your soft shot and ask yourself if each one was an ideal setting for that situation. For example, was the shutter speed close to being too slow for working hand-held, and was the ISO getting a little bit too high? Chances are, you might be dealing with a bunch of borderline settings that might not have been so bad by themselves but add up when used together. If conditions require that you use a bunch of borderline settings then that might be a sign you need to change the conditions. That might involve things like getting more light into the scene with a sufficiently powerful flash.

Beginners’ series on digital SLR photography

Other photography stuff

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