Split diopter vs Composite

[Tim Hole]

I'm doing a dramatic reconstruction as part of a charity gig on Epic and BMCC, there is a shot (locked without much movement in frame) and was considering using a split diopter for it, but trying to keep costs down (for obvious reasons) was wondering what the difference would be between a two shot composite and split diopter.

The only negative responses to the idea so far is it's cheating which is bullshit because a split diopter is a kind of cheating anyway, and 'it doesn't look right. Both reactions are not satisfying to me. Providing the lens doesn't breathe I don't see what difference it would make.

Am I missing something? Personal I've never been one for this purist mindset if it works, it works.

 

[David Mullen ASC]

If you can afford the composite work after shooting the foreground object against a green screen and pasting that against a background, both in focus, I don't see any philosophical problem with that IF the composite doesn't look like a composite. Or instead of a green screen composite, you could do a digital split-screen.

Another option is a tilt-focus lens, which would make objects along a diagonal plane fall into the same focus. The more you can also stop down the lens for more depth of field, the better the tilt-focus lens works.

I did some of these trick shots in "Akeelah and the Bee"... this one was done with a tilt-focus lens:

This one was done with a split-diopter filter:

If you look at the movie "Speed Racer" you'll see a lot of composites for deep focus shots.

I have no philosophical problem with doing the effect in post other than the fact that you are at the mercy of the quality of the post work -- if it's done well, that's great.

 

[Tim Hole]

The Tilt-focus is an interesting thought, I had forgotten about that prospect. Both the examples above are very clean and nicely done. I will see if I can get hold of a tilt-focus lens to test.

Otherwise I have two choices then. We have about 20% green screen work to do and remarkably ample time to fit it in, but the shot can easily be planned for a subtle split screen composite, which might be simpler and less post work—and my original thought.

I haven't seen SpeedRacer, I will add it to my research. I did some re-watching of Star Trek and scanned through Blow-Up.

Thanks David, as usual.

 

[David Mullen ASC]

Just as with conventional deep focus photography, the more you can stop down a tilt-focus lens, the better the deep focus effect will be. With split-diopter shots, that's not necessarily the case because too much depth of field can make the cut edge of the filter come into focus too much.

 

[BRANDON JAMESON]

Thank you, Mr. Mullen for your continued generosity.
What you give to our community by sharing your wisdom is priceless.

 

[Tim Hole]

Just as with conventional deep focus photography, the more you can stop down a tilt-focus lens, the better the deep focus effect will be. With split-diopter shots, that's not necessarily the case because too much depth of field can make the cut edge of the filter come into focus too much.

Thanks for the tip, I can see the logic behind that. One of the benefits of gigs like this is having the freedom to experiment.

Thank you, Mr. Mullen for your continued generosity.
What you give to our community by sharing your wisdom is priceless.

+1 Mr Mullen has been good to me over the last few years answering my questions, I am indebted to him.,the same is true for the forum as a whole, I tend to ask more questions than answers around here, but for the most part I am not treated with with kindness.