NTSC & PAL Questions
Published : 29th December 2004
OK, I have a question that really has stumped me.
When in Europe [50hz], is it possible to shoot and NOT get lighting strobe when using an NTSC video camera?
The old 50Hz versus 60Hz thing...
I know for film I can do the 25fps thing, or go 24fps @ 172.8 degrees...but what about video?
Jeff Barklage, s.o.c. writes :
>When in Europe [50hz], is it possible to shoot and NOT get lighting >strobe when using an NTSC video camera?
>The old 50Hz versus 60Hz thing...
I have shot 60i NTSC with a Philips camera that had a 1/100th shutter option. No problem.
Some LDK models actually had a 50/60 hz switch on them that allowed for shooting in 50 hz power situations.
> Is this is stupid question?
Only in that it probably should have been in video instead of general.
Regular plain vanilla NTSC - 1/100 shutter and you're good to go. Of course, if you're shooting available light, there's times when you'd like to turn that shutter off to help your exposure a bit...
Wonder if you can go with a 1/25 shutter at 24P with the SDX 900?? (Or an equivalent clearscan frequency?) Even 1/50 would be a help in low light.
>Is this is stupid question?
Nope, I've had 60Hz fluorescents pulsate slightly on PAL video. Not terribly noticeable, really. Very slight.
>I know for film I can do the 25fps thing, or go 24fps @ 172.8 >degrees...but what about video?
Not at all a stupid question...
You're shooting at 30fps or 60i, so you have to use lights that have NO
frequency relative to the electrical frequency, OR, if you use=20
electronic lights, use some that have a VERY HIGH electronic frequency, so you don't have to worry about the slight pulsating effect.
If you're shooting with low frequency lights, that have frequencies close to 50Hz, try to use a shutter at a high frequency (inverse the Light/Shutter at LEAST the triple, i.e. 150hz), and you shouldn't have any problem.
150hz at 60i =3D 2,5 illumination units per frame
150hz at 50i =3D 3 illumination units per frame
That's a 1/6 difference. I know it can seem to be a lot in film=20
exposure, but, as it is distributed on the frames, it's really easy to catch back in video. And you can see the result in real time on the monitor anyway
Camera, Steadicam Operator
>Wonder if you can go with a 1/25 shutter at 24P with the SDX 900?? (Or >an equivalent clearscan frequency?) Even 1/50 would be a help in low >light.
Synchro Scan in the SDX900 goes from 1/24.1 to 1/249.7 when shooting 24fps.