shooting 50i in the US/Canada?

[John Sharaf]

Hi Sam,

Well yes, it’s exactly the same phenomenon in SD and HD, you’ll need to adjust your shutter to eliminate flicker from the 60 hz lighting you’ll encounter with fluorescents, neons and magnetic HMI’s running on US power.

The magic shutter angle is 150° (1/25 s. x 150/360 = 1/60 s.).

JS

[Rafael Amador]

John’s formula should works mathematically.
You can also try the built-in anti-flicker filter (50Hz/60Hz/Auto).
As long as a flicker remains constant, should be possible to be avoided.
I have many problems with flicker when powering from generators or small grids on the country side.
rafael

http://www.nagavideo.com

[Sam Cole]

Thanks guys for your thoughts.
The other thing I was considering was shooting ‘natively’ and doing a mixed format edit in FCP.
Are there many pitfalls in having 50i and 60i media on the same timeline?

Sam Cole
On line Mastering Facility
FCP, Avid, Adobe
Sydney, Australia

[John Sharaf]

Only if there is sound!

[Rafael Amador]

[Sam Cole] “Are there many pitfalls in having 50i and 60i media on the same timeline?”
You can mix stuff with different size, pixels, codecs or field-order, without problem.but were FC doesn’t shine at all, is when mixing different time-base stuff.
The results will depend very much of the nature of the picture, but, if you put i60 on a i50 sequence, will look choppy: 10 Pictures have to be dropped per second.
If you put i50 stuff on a i60 sequence,10 new images have to be interpolated.
In FC you have no control on how those operations are performed.
rafael

http://www.nagavideo.com