fs700: how much light do I need for slomo?

G

Geesbert

Member
I am a food photographer sticking my nose into shooting video. I am currently using a hacked GH2, a Nex7 and a Canon 5d mark3, but I am very curious about the FS700's ability to shoot slomo. I just wonder whether my lights would suffice to go highspeed? We have half a dozen Hedler HMIs, which work very well with photography and regular film shutterspeeds.
If you shoot 200 Frames/S, do you have to use at least 1/400s shutterspeed?
Is there a general rule for the shortest shutterspeed you can use with HMIs?
What's the highest speed you can use with fluoresence lights? LEDs?

thanks a lot

Stefan
 
I think:
Kino flo good till 120fps
HMI really depends on manufacture but some are good till 120fps
LED's depends but should be good for hi framerates. Above 200fps.

Plasma light (hive lighting) good till 10,000fps
 
Alpern said:
I think:
Kino flo good till 120fps
HMI really depends on manufacture but some are good till 120fps
LED's depends but should be good for hi framerates. Above 200fps.

Plasma light (hive lighting) good till 10,000fps
Click to expand...


I'm not so sure that if you use only a Kino Flo 4bank Diva, it will be enought to be honest, excepted if you shoot closeup and part of a relative small size so you could put the light as close as possible... HMI light will be better or like always the sun will be your best friend
 
In general for film-style shooting you do use half the frame rate as your shutter speed, so yes, 1/400 for 200fps.

But another consideration is what type of lights you're using. If you're using magnetic-ballast HMIs, you cannot use any MOS-based camcorder to shoot at those types of shutter speeds. You could only do that with electronic-ballast HMIs.
 
thanks for all you input.

I did a test, but I am not shure how valid this is: I shot a tabletop scene with my HMIs and my 5dmk3 at 50fps at 1/2000, 1/1000 and 1/500 shutter speed and couldn't make out any problems. Does that mean I can use these lights at higher framerate?
 
To get a proper film look, you may want to keep the shutter opened at 180degree, so half of your shooting speed. You may see some light flickering with HMI magnetic ballast or maybe i imagine some electronic ballast. Be sure to get informations before buying your hmi light
 
Geesbert said:
I am very curious about the FS700's ability to shoot slomo.
Click to expand...

I must have ESP or something. Just hit me yesterday that High speed FS700 will be a boon to food photogs.
Incandescents that are fed voltage regulated power have virtually no flicker and therefore you can enjoy high speed shooting with them. I plan to use them in my food TVCs when I pick up the FS-700 (or comparable that Springs up at NAB this year) . Obviously I'd rather shoot LED or HMI.With LED you definitely want to shoot tests or study the emitter specs. But latest generation of PCB for LED deliver at least 120fps friendly lume. Once I've got that angle figured out is it will be my defacto studio illumination. I've also started fooling around with multiflash sync and 6fps full frame stills for psuedo high speed sequentials. Great for 5 second DSLR clips at 4K ;)
 
There's a lot of partial info here. Coming from the extreme high speed world of Phantom I can tell you that lighting is a significant consideration.

Above 120fps (in the US or other 60hz territories), tungsten lights can flicker because of the alternating current. DC power is okay. High wattage tungsten (2K & up) is okay because the lights are so damn hot that the filament doesn't have a chance to cool before the power cycles back up.

Flo lighting is a maybe but probably okay above 120 up to 450.
HMI lighting is also possible but can exhibit something called "arc wander," which looks more like a shimmer than a flicker.
Professional lighting LED fixtures are usually okay as long as they are not dimmed.

You cannot test using a still camera. The flicker is variance between frames, so you have to shoot multiple frames at high speed to see.
 
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