How to Choose the Best Handheld Shutter Speed

Unsteady pictures are usually throwaways, and the chief cause of unsteadiness is shooting at too slow a shutter speed when working with a handheld camera. There are some new innovations in insuring a steady shot, Auto ISO and image stabilization, known as IS. These modern techniques help in getting steady shots, but you should also rely on the old standby-- the 1/focal length rule.

You might think this photo on the left is sharp, but it's not. When I checked it on my playback monitor on the camera it looked OK. It was made at twilight with a 210mm lens and an exposure of f/5.6 at 1/125 second. 

Later, I enlarged the image on my processing monitor in my studio and saw just how unsharp it was. Applying the 1/FL rule would have resulted in a much sharper image (see text below). When shooting handheld you always introduce some "shake" into an image.

1/FL

The 1/FL rule is easy to figure out. Make the longest focal length of the lens the denominator in a fraction where 1 is the numerator. For example, shooting with a 300mm lens would give you a minimum shutter speed of 1/300 second (go up a bit to be safe and shoot at 1/500 second.) Note that this rule does not apply when shooting with a super-wide angle lens like a 12mm; 1/12 sec is way too slow and usually a 1/30 second shutter speed is minimum for most people.

Auto ISO

One very handy setup is working with the Auto ISO feature on your camera. This allows you to set both the maximum ISO (I usually keep mine at ISO 8000 maximum to avoid introducing too much noise, or grain), and 1/30 sec minimum shutter speed.

I

This shot was made handheld at a shutter speed of 1/60 second. The ISO AUTO feature was set with the highest ISO at 1600 and the shutter speed minimum at 1/60 second. The exposure was 1/60 second and f/4 at ISO 1200. Using AUTO ISO when doing low light work is a great way to minimize grain (keeping ISO within limits) while insuring a steady shot. 

Image Stabilization

When working with a long focal length zoom I generally turn image stabilization on to insure that I will get a steady shot. It is usually no problem when working wide, but if you are zooming in and out you might as well leave it on as a guarantee. This photo was made at 28mm with an exposure of f/11 at 1/150 second.

When I zoomed the 28-210mm out for a tele view with the wide exposure setting I knew it was too slow for a guaranteed steady shot, but with IS on I felt fully confident that the shot would be OK, even with the lens at maximum focal length. 

The Multiplier Effect

Keep in mind that when figuring the best shutter speed, add the “multiplier effect” to the lens and camera in use. For example, if you are using a 200mm lens with an APS-C or small sensor camera, the effective focal length for this setup might be 300mm, due to the “crop” the lens undergoes when throwing the image circle onto the sensor. In some cases the multiplier might be as much as 2X. And if you are working with a zoom lens on any camera, use the longest "effective" focal length on the zoom as the guide. I framed this shot with a 120mm focal length lens on an APS-C sensor camera, thus my effective focal length was 230mm, so I made sure that my shutter speed was set at (a minimum) of 1/250 second, and to be sure I made the exposure at 1/500 second.