Long exposure photography with a 10 stop filter

Note: This tutorial was originally published in 2013. The tips and techniques explained may be outdated.

The 10 stop ND filter is good fun to use, and I’ve had it long enough to think I’ve got the technique pretty much nailed. I’ve already spoken about the theory of long exposure photography with neutral density filters, I’ll go over it again with my current method and thoughts for anyone interested.

The Method

Switch to manual, go to f/16 and adjust the shutter speed to what the camera considers to be the proper exposure. Say something like 1/125 Sec.
Divide 1 by 125 (1/125) – which is 0.008
Times the 0.008 by 1024 (10 stops) – which gives you 8.192 seconds
I take this exposure length and multiply it by 1.5 for my final exposure length – which would be 12.288 seconds… or 12 seconds for convenience :) The reason for this is simple – filters don’t always cut the light by exactly 10 stops. Mine doesn’t.
Attach filter, switch to “Bulb” mode and take the photo!

Some thoughts on composition for long exposure shots

A long exposure is pointless without some movement. Moving clouds, water, driving rain, sleet or snow, crops in the wind, people going about their business and vehicles all work.
The best way to make things look like they are moving is to have something in the frame that is completely stationary. I normally make this the subject, with the moving mass of whatever being secondary.
Watch out for moving things in the immediate foreground. I’ve been caught-out by annoying blades of grass going blurry right in front of the lens. Quite annoying when you find this after waiting 8 minutes for your exposure to finish! Long exposure is a type of photography where great care is required in composition because of the time invested in taking a single shot.