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Cinema-friendly flash/ strobe units

ian@...
 

Hello CML,

I'm planning a scene of a fashion stills shoot and trying to use a single strobe source that would provide the stills photographer a strobe triggered by her camera (via synch cord or remote) as well as give a good-looking flash effect on a Red (think Lighting Strikes Paparazzi).  The unit would ideally work with stills-like gear (umbrellas etc.) as they'll be in shot.

Alternatively, does anyone know a way to synch flash effects from cinema lighting gear to a still cam shutter?  Are there any strobe units with a longer flash duration that will look good in motion?

Thanks all!

Ian Kerr csc
Cinematographer
Vancouver, Canada

Barry Goyette
 

Rotolight makes a couple of smaller “effects” LED marketed at photographers as strobe units…these will probably have the longest duration although they are not incredibly bright (which may be a good thing). Otherwise, in traditional flashes …. duration is a product of power sent to the head. More power=Longer duration. In particular, older profoto battery units (acuteB) had pretty long durations at full power…you should be able to find still in rental most places. As far as avoiding tearing and sync problems with a red…IDK.

Barry Goyette
Stills Motion Design
California USA



Alternatively, does anyone know a way to synch flash effects from cinema lighting gear to a still cam shutter? Are there any strobe units with a longer flash duration that will look good in motion?

Argun Tekant
 

Hi Ian,

The reason regular photographic strobes look bad in cinema with digital cameras is, the speed of the flash duration vs. the speed of reading the sensor. 

A quality studio strobe will flash at nearly 1/10000th of a second (some better ones claim 1/15000)

At that short a time, the flash can happen at the off cycle moment for the sensor, or (depending on how the sensor is read) only highlight a thin line in the frame. 

So, the solution is to extend the flash duration to cover the whole off-read cycle of the sensor. 

I am sure there are proper cinematic solutions to this, but photographers have some solutions for a different problem, that might be useful. Possibly at a much cheaper cost. 

The most common solution you will find these days would be High-Speed-Sync. 

Photographically, to allow very high shutter speeds in stills, the strobe units “strobe” at a very high frequency for around 100ms (1/10th is a second) simulating a very long strobe. That should be adequate to always light up a frame. 

There are some downsides to it that may or may not be a deal breaker for you:
- on some electronic shutter sensors they create a banding effect. Whether this is a problem for a single frame in a moving would need testing. 
- you can only use it at higher power settings, which might need some way to externally cut down the light

Different brands provide this. They need their own camera triggers that only work with supported brands and models. The big 2 is always covered, but if it is required that the actor to use a certain brand/type of camera that’s not supported, it might need a more creative solution to that. 

Broncolor have their own system they call HS. If you believe the marketing, it won’t cause the banding I mentioned above. But more importantly, they will work more reliably for long shoots, multiple takes. One practical problem with HSS is, it heats up the units, which will cause them to shut down after a while if used heavily. Presumably, Bron units are better at that. But I personally never used one. 

Argun Tekant
Photographer 
SF Bay Area


On Sat, Jun 30, 2018 at 7:21 AM <ian@...> wrote:
Hello CML,

I'm planning a scene of a fashion stills shoot and trying to use a single strobe source that would provide the stills photographer a strobe triggered by her camera (via synch cord or remote) as well as give a good-looking flash effect on a Red (think Lighting Strikes Paparazzi).  The unit would ideally work with stills-like gear (umbrellas etc.) as they'll be in shot.

Alternatively, does anyone know a way to synch flash effects from cinema lighting gear to a still cam shutter?  Are there any strobe units with a longer flash duration that will look good in motion?

Thanks all!

Ian Kerr csc
Cinematographer
Vancouver, Canada