Fluorescent Flicker (shooting in Asia) at DVinfo.net

Christopher Rufo · February 10th, 2008, 11:22 AM

Hello,

I've been reading this forum for some time, but this is my first post.

I'm on a documentary shoot in China and am having a hell of a time with indoor fluorescent lighting. The electric current out here is 50hz, which would need a 1/50 shutter speed to avoid fluorescent flicker. Unfortunately, the A1 runs a 1/48 shutter speed and not 1/50, so I'm still getting some annoying flicker. (It's usually low light as well, so I can't put it at 1/100.)

Any help out there? Is there any kind of workaround that would allow me to shoot at 1/50 shutter? Or some other kind of fix I'm unaware of?

Thanks in advance!
Chris

Steve Sobodos · February 10th, 2008, 02:35 PM

Have you tried the clear scan function? It lets you adjust the shutter frequency in much smaller increments. It is made to eliminate flicker in video screens but might work for you.

Jack Walker · February 10th, 2008, 02:51 PM

You can also shoot at 1/100 shutter.

Last some I shot several hours in Lithuanian (50hz) in a large room with mixed lighting, some of it old flourescents and other odd types of lighting.

I shot everything at 1/100 and everything looks good.

I used 3db gain for everything and it looks great. I think you could go to 6db gain without any problems.

But to get back to the question, I think 1/100 is your answer.

Don Palomaki · February 11th, 2008, 08:11 AM

However, shooting at more than 2x the power line frequency may result in drifting color balance due to slight variations in light output from the fluorescent lamp over the power half-cycle.

Christopher Rufo · February 11th, 2008, 11:18 AM

Thanks for all of your quick responses.

The clear scan function only goes as low as 60.1hz, which isn't low enough to match the electrical current (and at 100hz it actually makes the flickering worse, for whatever reason).

1/100 shutter definitely solves the flicker problem, but you get the low light problem, as you mentioned. I'm shooting in a poor region of Western China, which in practice means a very poorly lit region of Western China. I've tried boosting the gain +6db, but the image suffers quite a bit--noisy as hell, on top of it being soft anyway in those kind of lighting situations.

So, I guess it's a trade-off: slight flicker at 1/48 shutter or a noisy gained image at 1/100... a trade-off Canon could have avoided if they had included 1/50 shutter speed (ugh!).

Thanks again for your suggestions. If anyone else has any other possible solutions, I would be extremely grateful to hear about them.

Best,
Chris

Bill Pryor · February 11th, 2008, 01:20 PM

Probably the PAL upgrade would give you the 1/50 shutter. I think Canon does that for $500 (USD). You'd be shooting in PAL, of course.

Don Palomaki · February 11th, 2008, 02:22 PM

Yes, the PAL version camcorders do have 1/50 shutter. Isn't PAL the standard format in China?

Jack Walker · February 11th, 2008, 03:40 PM

Made Post in Wrong Thread!!???

February 10th, 2008, 11:22 AM	#1
Christopher Rufo New Boot Join Date: Feb 2008 Location: Seattle, WA Posts: 8	Fluorescent Flicker (shooting in Asia) Hello, I've been reading this forum for some time, but this is my first post. I'm on a documentary shoot in China and am having a hell of a time with indoor fluorescent lighting. The electric current out here is 50hz, which would need a 1/50 shutter speed to avoid fluorescent flicker. Unfortunately, the A1 runs a 1/48 shutter speed and not 1/50, so I'm still getting some annoying flicker. (It's usually low light as well, so I can't put it at 1/100.) Any help out there? Is there any kind of workaround that would allow me to shoot at 1/50 shutter? Or some other kind of fix I'm unaware of? Thanks in advance! Chris

February 11th, 2008, 08:11 AM	#4
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,489	However, shooting at more than 2x the power line frequency may result in drifting color balance due to slight variations in light output from the fluorescent lamp over the power half-cycle. __________________ dpalomaki@dspalomaki.com

February 11th, 2008, 11:18 AM	#5
Christopher Rufo New Boot Join Date: Feb 2008 Location: Seattle, WA Posts: 8	Thanks Thanks for all of your quick responses. The clear scan function only goes as low as 60.1hz, which isn't low enough to match the electrical current (and at 100hz it actually makes the flickering worse, for whatever reason). 1/100 shutter definitely solves the flicker problem, but you get the low light problem, as you mentioned. I'm shooting in a poor region of Western China, which in practice means a very poorly lit region of Western China. I've tried boosting the gain +6db, but the image suffers quite a bit--noisy as hell, on top of it being soft anyway in those kind of lighting situations. So, I guess it's a trade-off: slight flicker at 1/48 shutter or a noisy gained image at 1/100... a trade-off Canon could have avoided if they had included 1/50 shutter speed (ugh!). Thanks again for your suggestions. If anyone else has any other possible solutions, I would be extremely grateful to hear about them. Best, Chris

February 11th, 2008, 02:22 PM	#7
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,489	Yes, the PAL version camcorders do have 1/50 shutter. Isn't PAL the standard format in China? __________________ dpalomaki@dspalomaki.com

February 10th, 2008, 02:35 PM	#2
Steve Sobodos Regular Crew Join Date: Dec 2007 Location: Lake Forest, CA Posts: 106	Have you tried the clear scan function? It lets you adjust the shutter frequency in much smaller increments. It is made to eliminate flicker in video screens but might work for you.

February 10th, 2008, 02:51 PM	#3
Jack Walker Trustee Join Date: Jun 2006 Location: Burbank Posts: 1,811	You can also shoot at 1/100 shutter. Last some I shot several hours in Lithuanian (50hz) in a large room with mixed lighting, some of it old flourescents and other odd types of lighting. I shot everything at 1/100 and everything looks good. I used 3db gain for everything and it looks great. I think you could go to 6db gain without any problems. But to get back to the question, I think 1/100 is your answer.

February 11th, 2008, 01:20 PM	#6
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	Probably the PAL upgrade would give you the 1/50 shutter. I think Canon does that for $500 (USD). You'd be shooting in PAL, of course.

February 11th, 2008, 03:40 PM	#8
Jack Walker Trustee Join Date: Jun 2006 Location: Burbank Posts: 1,811	Made Post in Wrong Thread!!???