Gaffer & Gear 42 Flicker Free Rates

Gaffer & Gear 42 - Flicker Free Rates
A quick and basic formula for flicker free frames rates with location lightning.

[@raredreamfootage]

Interestingly, I was on a shoot with four very different cameras. And what we noticed was that the rolling shutter speed of each camera affected which shutter speed they could use in the SAME room under the SAME flickering lighting conditions. The camera with the fastest rolling shutter performance of the four (A7iii) had a larger range of shutter speeds it could use whereas the slowest of the four, the Sony A6400 (39ms in 4K), could not find a shutter speed that worked. Therefore when considering shutter speeds to deal with flickering lights, you must consider the rolling shutter speed of your camera as well.

[@jamesseiber]

Thank you for the info. I notice, that it´s getting more and more tricky, just shooting at your normal shutter speed with leds all over the place. some work, some don´t. Most of the time I will take my Iphone and check the lamps. If they don´t flicker on an Iphone, they most probably won´t flicker on the Alexa..

[@gaffergear]

Yes, especially on dimmers

[@xx1simon1xx]

i wish i had seen this last year, i shot a comercial on alexa lf, 90 fps all the time, and then phantom in 500 fps sometimes. i had all m series hmis and skypanels (m90s, m18s, m40s) so all good there as those go up to 1000 hz, buuut, the dop wanted practicals, i told him we could test it but that i was sure it wouldnt work, not at 500fps obviously but also not at 90 (it didnt) i was sure of it but couldnt logicaly explain it, felt pretty stupid, even though i was right bought a bunch of astera bulbs yesterday so i wont have that problem again (not throwing out my bulbs though, nothing touches true tungsten)

[@davidhrzenjak]

From my experience fps are not that important. In my country the frequency is 50hz but every fps my camera has (24,25,30,50 & 60) works as long as my shutter speed is set to 1/50 or 1/100. I don't know how or why that is because your explenation seems very logical but thats just my experience.

[@gaffergear]

Probability more to do with the fact that most lights are LED these days and run at higher frequency then 50 or 60hz. It's very unusual to come across a sodium vapour high bay light these days.