Cropping instead of using a longer lens

[Alex Donkle]

For an upcoming shoot the longest lens I have access to is a 50mm, but for some scenes I know I'd like to push in a little closer to give me, say, what an 85mm would.

We're shooting in 4k and finishing in 1080p, so my thought was simply cropping a 50mm shot to give the impression of having used a longer lens, however I'm curious if anyone has any experience with that. Or if that's going to look like an obvious cheat I can just try and just block the dialog scenes in a more "Spielberg" style.

[jimhare]

It definitely works, I've done it successfully and it works well.

I think the biggest issue is the perceived loss of depth of field.

[Tom Lowe]

Cropping to 3K should be okay, but I would not shoot 2K and hope to post at 1080p. That's just my opinion.

[Harry Clark]

I agree with Tom. In a pinch, I've done the 3K crop and for regular HD or SD it looks terrific. I've also shot entire spots at 3K where there is a lot of 60 fps stuff, for consistency. I must give the Red Team credit here; 3K is a nice option.
For my taste, however, 2K always looks a bit too noisy and soft to cut with 4K.
You should do a test if you can, outputting and evaluating on a large monitor or whatever your delivery medium is.
Cheers,
Harry

[Ted Chu]

IMHO, yes you can always match frame size but choosing the "right" focal length, distance, and lens glass will always change from shot to shot, script to script.

[David Mullen ASC]

I'd avoid relying on cropping as a standard way of achieving the inbetween focal lengths, as opposed to using it just occasionally to adjust the framing of a shot.

For one thing, it would get awfully confusing on the set and in post, and it may lead to some inconsistencies in texture, sharpness, etc.

[J.R. Hud]

Or if that's going to look like an obvious cheat I can just try and just block the dialog scenes in a more "Spielberg" style.

I was curious as to what you meant by this ?