BLACK CYC STROBES
Posted 29 November 2007 - 06:42 PM
The other thing I want to do is emulate poeple snapping his picture with strobes...however real still camera stobes are so quick that you can't really get illumination for a long enough duration to see the subject. I want the image to be completely black...and then you see the person..bam! because of the blast of light that illuminates him...then it falls off to complete blackness again. I like the idea of doing this with tungsten lights because they seem to fall off slower due to the fixtures still being hot and fading to black however I know a product like "lightning strike" customarily uses HMI.
I want to shoot this at 64 fps 45 mm 180 degree shutter.
In summation for the strobes part....I need it to be all black...the viewer sees nothing, then a flash of light long enough in duration so that the viewer can tell who the subject is, but short enough so that it looks like a camera has snapped his photo.
Any suggestions as to which tools to use how... wattage I will need to be able to support...links to articles...anything would be great.
Posted 29 November 2007 - 06:50 PM
If you've got the budget, use an intelligent light like a High End Studio Color, MAC 2000, etc. They can be programmed to do what you want with full control over turn on / turn off / repetition rate. You'll also need an intelligent light board like one of the Whole Hogs to control the light on a DMX buss. Many intelligent lights use MSR (same technology as HMI) lamps with magnetic ballasts so you must use HMI safe frame rates.
In summation for the strobes part....I need it to be all black...the viewer sees nothing, then a flash of light long enough in duration so that the viewer can tell who the subject is, but short enough so that it looks like a camera has snapped his photo.D
Posted 29 November 2007 - 08:43 PM
As for lighting, just keep all your lights (including the strobes) well-flagged off of the black background.
Why 6-4 fps? That seems like an irregular number. And I assume 45mm was a typo...
Posted 30 November 2007 - 12:08 AM
Dataflashes are nice on stage but strobe flashes are too short. Depending on the camera's shutter angle you are apt to lose at least half the flashes. The "beat" between the strobe rate and the fps rate is why filmed strobes often look so random - they don't look like live strobes because the flash rate appears to stutter on film. By going to intelligent lighting you can stretch out the on duration enough to get the flashes on for at least one entire frame.
Check out Dataflash units for multiple programmable heads. ............
I suspect out in Hollywood some does have something like Dataflashes that have been modified to take a sync pulse and phasing information from the camera - but I bet they don't rent cheap! On a mirror reflex camera you wouldn't see the flash because the light would only be present when the shutter was open - wouldn't that drive the average operator and video village denizen nuts.
Posted 30 November 2007 - 09:59 PM
from what i have heard recently, dataflash is being phased out. i used something new a couple of weeks ago, i will find out what it was for you. it was a less expensive option, like the dataflash, but there seemed to be more control over the duration of the flash...
anyway, it should look cool in slow motion! have fun...