split diopter effect

[David Edward Keen]

Is it necessary to use a split diopter lens on a simple dslr? are they even made? Might it be best to try it in post?

[Mark Dunn]

A split dioptre is just half a close-up lens. You just screw it into the front of the camera lens.

If you can get enough DoF, of course, you don't need one, but that's more difficult with a large-sensor DLSR.

You can't increase DoF in post, a scene is either in focus or it isn't.

[David Mullen ASC]

Yes, they sell split diopters for still cameras. As Mark says they are just a regular diopter (close-up filter) cut in half so one side is clear.

 

Since the split diopter creates and image with two planes of focus, the only way to fake that in post would be to do a split screen shot, two separate takes where the focus is set in a different spot, combined in post with a soft split screen. That's possible, but if it's a shot of two people talking it would be hard to get the two actors to be in sync with each other from two different takes unless there isn't a lot of back and forth. The whole point of the split diopter filter is to do it in-camera.

 

As for it being "necessary on a DSLR" I'm not sure what that means. You use the split-diopter when you want that effect of half the frame focused on one spot and the other half focused somewhere else.

[David Edward Keen]

Thanks, yeah I'm just jumping into lenses.

Edited October 9, 2015 by David Edward Keen