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NTSC & PAL Questions

Published : 29th December 2004

>Hello everyone!

>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?

>Is this is stupid question?

Cheers,
Jeff Barklage, s.o.c.
US based DP
www.barklage.com
view reel: www.reelsondemand.com


>Jeff Barklage, s.o.c. writes :

class="Paragraph">>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.

>Mark Smith


class="Paragraph">> 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.

>George Hupka
Director/DP
Downstream Pictures
Saskatoon, Canada


>Hi,

class="Paragraph">>Is this is stupid question?

>Nope, I've had 60Hz fluorescents pulsate slightly on PAL video. Not terribly noticeable, really. Very slight.

>Phil Rhodes
Video camera/edit
London


class="Paragraph">>I know for film I can do the 25fps thing, or go 24fps @ 172.8 >degrees...but what about video?

>Yark Yark...

>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

>Zefred
Camera, Steadicam Operator
Paris, France


class="Paragraph">>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.

>Robert Goodman
Author/Photographer
Philadelphia, PA