Wednesday, 7 August 2013

How slow is too slow?

In this age of wonderful highly sensitive sensors that perform fairly well in low light with acceptable noise we're all tempted to shoot in situations that even a few years ago we would not have tried without a tripod. That does bring up the question, just how slow is too slow?

A street performer in the evening 85mm 1/125th f/1.8 iso 4000

What do I mean by too slow? Well, there is a point that the shutter will be open for so long that you won't be able to hand hold the camera without some blur. It's important to experiment with how slow you could go for the slowest shutter speed and still hand hold without blur.

Whenever this subject comes up people spout all this complex maths and justifications. I get scared of people like that. They think too much. I've been around photography for a while - so I do understand the concepts, but someone with less experience is going to run away and hide.

To be absolutely correct, they're right - BUT you can just keep it simple for ANY camera if you want a rule of thumb.

In my experience, double your focal length is the slowest shutter speed you should try and hand hold. So if your lens is 200mm then the slowest is 1/400th of a second. If it's 80mm then the slowest is 1/160th of a second. Some people will be able to do better most of the time, but is it worth the risk?

Yes, I hear you groan you can of course go slower if you know the math and your focal length and your crop factor and and and... I'm ignoring IS (Image Stablisation)... because I'm keeping it simple. IS can help you but if you want the best results I'd stick with simple. Below these speeds use a tripod.

Don't have a tripod with you? Improvise - ground, poles, bins, whatever. The first shot at the top of the article is braced on a pole, these below are either on the ground or other objects.

Shot from the ground this is a 4s exposure at f/9 iso 200

Using a wheelie bin at Luna Park in place of a tripod 30s f/22 iso 100