Split diopter filter strengths

[Stephen Pruitt]

Hi all. . .

I have NEVER even seen a split diopter filter in person, but I am very interested in using one on a few shots in our next film. We are a Canon L/Sigma ART shop, and I'm wondering what strength of diopter I should actually buy for this purpose. If you were to buy just one, what strength would it be? How about two?

Thanks so much.

Stephen

 

[Frank Martin]

1/2,1,2,3 are the strengths. Buy a +1
and have fun . They are cheap used

 

[Frank Martin]

Or try a swing and tilt lens

 

[Stephen Pruitt]

I did have a tilt shift, and found it somewhat useful, but not quite as much as what I'm looking for.

Thanks.

Stephen

 

[RobMNeilson]

Stephen I recommend that you grab some 138mm diopters. More expensive, but so long as you dont mind using a mattebox with them you're future proofed for lens choices down the road. With 138mm you can get + 1/8, 1/4, 1/2, 1, 2, 3.

 

[David Mullen ASC]

You need more than one because you are never sure what the distances will be to your near subject versus your far subject (you set the lens focus for the far subject because that's the clear portion of the filter, and then use a strength of diopter to get your near subject to fall into focus). Often you end up using the +1 or +2 most of the time though.

They also work best in the moderate wide-angle to normal focal lengths, not too wide nor too long a lens, and not too stopped down. It's a balancing act because you don't want the dividing line to be too sharp-edged but you don't want it to get too large and blurred either.

 

[Peter Lyons Collister ASC]

So Diopters are "positive" lenses in a sense. And the way they work is this formula. With your primary lens set at infinity if you use a +1 diopter it will focus an object properly a meter in front of the front element. So a +2 would focus an object 1/2 meter in front of front element. Obviously then you can focus the taking lens closer but this gives you a guide. Rarely are +3 diopters used but that would focus an object 1/3 meter away from FRONT element.

Hope this wasn't confusing.

 

[Stephen Pruitt]

This is all super helpful information! Thanks gentlemen!

Stephen