165 degree shutter 50hz flickering

[Juha Mattila]

Hello all,

 

Im sorry if this subject have been covered already but I couldn't find fully comprehensive answer to it.

I have Arri IIB with Tobin crystal motor and I need shoot on location under the prevailing lights. Most likely fluorescents. Some say you can shoot 25fps 50hz lights with no problem at 165 degree shutter but I have also reed that it can still produce flickering. Before I do the test I wonder if some one has already done it or knows how it is?

 

Thank you,
Juha

[Stuart Brereton]

If you're in a 50hz country, you should shoot at 25 fps with a 180 degree shutter. With fluorescent lights, it is possible that they may flicker due to old, magnetic ballasts. There's not much you can do about this. If it is a single fixture, you can just turn it off, but if it is multiple fixtures, it is likely that they are all flickering at different rates, which makes it impossible to compensate for.

[Simon Wyss]

You want 172.8 degrees shutter opening angle at 24 f. p. s. in a 50 Hertz grid.

[Juha Mattila]

Thanks guys! That was what I was afraid of. I just have to rent a camera then. It's a shame that I cant use my own IIB for that kind of locations...