EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: dexters_lab on November 29, 2014, 12:52:38 pm
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A while ago i improved the lighting in my man-cave with two 5ft strip florescent lights, i knew at the time it was going to be a temporary thing but they are cheap to install.
So since then i have been having a few issues with flicker on my camera so i'm thinking i should switch to something else.
Does anyone have suggestions to something available in the uk that doesn't have 50hz flicker and has good colour balance, i'm thinking LEDs but dont want to spend a fortune
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Take some electronic ballasts and feed them with 310VDC from a SMPS input stage. That will give flicker free light.
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Don't know much about shooting vid, can you set the shutter speed independent of the FPS?
If so, shooting in multiples of mains half cycle period gives even lighting irrespective of lighting phase.
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Dave controls frame rate to 50Hz so as to have no beat.
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I do professional video production in my spare time and in my experience fluoro lighting (unless it's the professional kind designed for video) is a pain in the ass, so is cheap LED lighting.
Some consumer cameras will have a 50/60hz software switch will help compensate for flicker otherwise, lower your shutter speed. If you're recording at 25fps, manually set your shutter to 1/50 or 1/60 if you're working with 30fps video.
If you're looking to replace your lighting, don't worry too much about colour temperature, get whatever makes you happy, you should be white balancing your camera according to your lighting set up anyway if you want to do things properly and get accurate colour reproduction.
You can also buy "flicker free" ballasts but I haven't had any experience working with those and they are probably pricey.
Keep in mind, some LED lights will flicker at high shutter speeds too.
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Dave controls frame rate to 50Hz so as to have no beat.
No I don't. I shoot with aperture priority, not shutter priority, the camera chooses the shutter speed based on the available light.
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Replace the ballests on the tubes with good quality electronic HF ones.
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thanks guys
camera does have manual mode which i have tried before but it can be a little awkward, think i might try making an entire video in manual mode and see how it goes.
we are 50hz here and the camera minimum is 50hz, when not in manual mode the camera will up the shutter speed rather than stopping down the iris so when i put something bright in view i start to get banding
failing that i'll drop in some HF ballasts into the light
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Even though you're in manual mode, you can still have some functions in "auto" such as focus, iris etc... so that should make your life easier.
What kind of camera are you using (make/model) ?
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Simply replace the old magnetic mains-frequency ballasts with solid-state (ultrasonic) ballasts.
They operate on the same mains power, but the fluorescent flicker is way above anything the camera can discern.