Shutter Speed

[jrbrown1991]

Shooting off-hand, how do I determine the shutter speed needed to prevent motion blur, with image stabilization?
And, without IS?

Thanks.

[toriaj]

If we're talking about camera shake, (meaning that your subject is still so you only need to control the inevitable shake of your hands holding the camera. Think taking pictures of the lighted Statue of Liberty at night.) the old rule of thumb used with 35mm cameras was 1/focal length. So if you were shooting at 50 mm, you could go as slow as 1/50 sec with no camera shake. Now that our digital cameras are (roughly) 1.5 crops, we need to adjust the rule of thumb to 1/focal length x 1.5. So, if you're at 50 mm on a Nikon crop camera, you can go no lower than 1/75 sec and still handhold the camera without camera shake. Voila, perfect clear picture of the Statue of Liberty at night.

BUT

If we're talking about freezing motion blur of the subject, that's a whole different issue. Say you're taking picture of the kids jumping on the trampoline. If you used the shutter speed of 1/75 sec., you wouldn't have camera shake -- but the kids would be blurred because of their own motion. To freeze the action, you need a shutter speed no longer than 1/250 sec, sometimes faster. Some sports, such as basketball, and of course things like car racing take even faster shutter speeds, like 1/500, 1/1000 or even higher. HTH

[Visual Reality]

I stick to 1/125 minimum if there are live subjects (people, animals) moving slowly. However you may still get some blur in hands, feet, or other extremities (!?) so up to 1/250 may be needed. For fast moving kids or animals you may need between 1/250 to 1/500, the higher end of that would be moving more towards sports action. Most of the time you won't need more than that but there are exceptions so of course, YMMV.

1/80 can still get the job done, and even lower if the subject is dead still (posing). Otherwise for candid work I try not to go below 1/125.

Now that's motion blur. For camera shake, try to keep an eye on your focal length. 1/100 for 100mm, 1/200 for 200mm, 1/300 for 300mm, and so on. That isn't an exact formula, but is a good guideline to follow.

Edit: Tori types faster.

[jrbrown1991]

That's With image stabilization, or without?
(And I meant camera shake, my hand movement / pulse)

[TheWengler]

To avoid camera shake w/o image stabilization use, SS = 1/(focal length * crop factor). If you have image stabilization then it depends on the efficiency of the IS in your camera/lens. If you need 1/100 sec to avoid camera shake w/o IS, but you have a 2 stop IS lens, then you only need 1/25 sec to avoid camera shake (2 stops difference between 1/100 and 1/25).

[pianoplayer88key]

I've so far found with my hands it was 1/true focal length of the lens, not the 35mm equivalent.

For example, with my S1 IS, with IS on I could routinely get fairly sharp pictures handholding 1/8" at maximum telephoto (58mm actual FL, 380mm 35mm equiv FL). This changed to approx. 1/60" with IS off.

[jrbrown1991]

Canon 55-250mm f/4-5.6

How good's my IS?

[TheWengler]

You can look that up on the Canon website.

[jrbrown1991]

a 250mm lens steadily was 1/250th of a second, with Canon's 4-stop stabilization correction, you could hand-hold at shutter speeds as slow as 1/15th of a second.

---

;) Thanks.
Although the Canon site doesn't tell me that info on the 100-400mm USM IS, it'll be quite a while before I have that much $$.

[TheWengler]

Without IS, SS = 1/(250*1.6) = 1/400 sec...with 4 stop IS that gets you to 1/25 sec. You won't be stopping any motion at that SS though.