90 fps (and other non-multiple fps) slow-motion footage in post-production: what to expect?

[Anzer Sizov]

Dear friends, what should I expect when shooting slow-motion with rather unusual fps for a standard 25 fps project? Say, 90 fps?

My strategy is to try to avoid any 50/60 Hz related equipment and then accurately slow down the footage in post to maintain the correct shutter speed of 180 degrees.

Does it make any sense?

Any advice would be much appreciated!

 

[Phil Rhodes]

That sounds like the right approach.

Bear in mind that quite a lot of things that you wouldn't think will flicker actually do; there's more flicker in modern LED lights than there was with fluorescent, for instance.

90 isn't that fast; if you were talking about 900 you'd have more concerns. Some HMIs do okay at lowish rates, but may start to cause problems at really high frame rates.

Test everything.

P

[Bruce Greene]

Why not shoot 100fps?

[Anzer Sizov]

39 minutes ago, Bruce Greene said:

Why not shoot 100fps?

Bruce, 90 fps seems to be the maximum available in this mode, i.e. Open Gate ARRIRAW on Arri Alexa SXT... Going to double check, though!

[Anzer Sizov]

2 hours ago, Phil Rhodes said:

That sounds like the right approach.

Bear in mind that quite a lot of things that you wouldn't think will flicker actually do; there's more flicker in modern LED lights than there was with fluorescent, for instance.

90 isn't that fast; if you were talking about 900 you'd have more concerns. Some HMIs do okay at lowish rates, but may start to cause problems at really high frame rates.

Test everything.

P

Hello, Phil! Thank you for your notes on flicker and high frame rates. I hope I'll be able to run a few tests.