What shutter speedshould I be using for fluorescent light

ifownlee41nite@mac.com

ifownlee41nite@mac.com

Well-known member
What shutter speed should I be using on the dvx100b for fluorescent light

I have a shoot tomorrow morning, and I need this information pronto.

Really would appreciate it. I've been searching for a thread and came up empty.

Thanks in advanced.

Hey Richard if your still up

Help!!!:dankk2:
 
I sent you a PM but here is a formula to use

Safe camera speeds with 60hz lighting :

Camera speed in fps = shutter angle / 3 / LPEP

Where LPEP = number of light peaks that you want to capture per exposure
period (typically 2 per cycle, or hz).

Safe shutter angles with 60hz lighting :

Shutter angle = speed in fps * 3 * LPEP

But you may not need it if the output frequency is high enough on the ballasts that are in the lighting you'll be using. For instance, modern electronic ballasts mostly output at a very high frequency which keep flicker from being a problem. Just 60hz magnetic and electronics are the ones to watch.

Hope this helps.
 
If you're in an NTSC territory, stick with 1/60th. Don't use 1/50th, don't use "shutter off", and definitely DEFINITELY don't try using a fast shutter speed like 1/250th.
 
I'm confused. So you cant use 1/50, 1/48 or slow shutter speeds with the dvx when you use fluorescent lights? CFL's are included in this?
 
With the homemade Kinos I created, I often shoot at 1/24th and 1/48th as well as 1/60th shutter speeds with no flicker. I specified and sourced super high frequency ballasts for the lights and have no problem with flicker at any shutter speeds.

I don't think you would have any problems with real Kinos doing the same. You will have issues using non-professional, non-high speed ballast flouros of any kind.

Barry's advice is probably the safest, I just wanted to relate my experience with my own homemade lights.

Best,

Dan
 
Most all the big names in ballasts today (Advance, Fulham, Universal, Phillips, Osram, Cool Lights ;-) all use driving output frequencies of between 25000 and 40000 hz. I've heard of higher than that but they're rare.

You don't need a Kino Flo for sure as there are plenty of great ballasts around in lots of other types of fixtures, from pro level to home depot grade 4 foot ceiling fixtures and even DIY.

It's just not a problem at that point unless you're doing something like 1000FPS work and then its possible it could be a problem. I've even heard of people having trouble with tungsten lighting at that speed. Some self-ballasted CFLs and some cheaper electronic ballasts have much lower frequencies (even 60hz range like an older magnetic ballast). The trouble is, you really don't know for sure until you use them. No way to tell beforehand in existing lighting unless you test it by taking some footage.

When it's the case that you have the lower frequency ballasts, you have to pay more attention for sure and use the HMI flicker formula which applies to fluorescent and any 50 to 60 hz ballasted lighting technology.
 
By the way, one thing I've discovered is that it's pretty easy to detect the worst culprits with your peripheral vision. It seems that, head-on, it's not always so easy to detect thanks to persistence of vision (the same effect that allows us to watch a 24FPS film and not see flicker), but if you turn your head just a bit so you're not looking directly at the light source or the spot on the wall (sort of letting it fall into your side vision so-to-speak) that it's making, you can detect flicker through your peripheral vision. Works every time for me on a cheap 50 or 60 hz magnetic ballast that doesn't have some other trickery involved to keep flicker from not being a problem.
 
"Some self-ballasted CFLs and some cheaper electronic ballasts have much lower frequencies (even 60hz range like an older magnetic ballast). The trouble is, you really don't know for sure until you use them."

Can someone recommend a specific brand/model of self-ballasted CFLs that has a high enough Hz to work w/ any frame rate and shutter angle without worrying?
 
Well I imagine the bluemax ones work okay and I haven't heard any bad reports on the Home Depot N:Visions either for flicker nor did I encounter it when I've used them but then I don't venture off into higher shutter speeds or abnormal frame rates very often.

We found a good source for these in China now so we're probably going to finally have some soon on our site unless we run out of money for inventory this order which could happen as we have a lot of new products. I'm planning on carrying a 45w and a 200w model at least in 5600K. CRI 90 and flicker free at all shutter speeds and frame rates I've tested with.
 
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