Nice new toy, but how might I...

Mark in SD · 05-23-2003, 01:27 PM

OK. I got a brand new Nikon SB-80dx flash unit for my anniversery. It is VERY nice and has some interesting capabilities, including very short flash durations and a repeating strobe function.

The repeating strobe function looks like something that I would like to play with. The general theory I know. Long shutter speed (probably Bulb) and adjust the exposure for the strobe subject. How, however, do you keep from overexposing the background? Is the only way to use a dark background?

This is something I'd like to play with but need some exposure advice/help.

bmac · 05-23-2003, 01:38 PM

THe easiest way would be to use a dark background. Otherwise, you'll need to do some math. More math than I am willing to do

Just make sure to use F16, 22, or smaller and not keep the bulb open longer than the exposure for the background calls for.

Donald Miller · 05-23-2003, 02:06 PM

The easiest is, as Brian addressed, to use a dark background. However, if that is not possible or feasible, you will need to determine the light output over a series of "pops". From that you will be able to determine lighting ratios. So long as the background is five stops below the lit object the background will render black even if it is in reality snow white.

George Losse · 05-23-2003, 03:28 PM

Also try to keep the room lights to a minimum. They will begin to expose even a black backgroud on a long exposure.

Have fun,
George

Mark in SD · 05-23-2003, 03:50 PM

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (dnmilikan @ May 23 2003, 10:06 AM)</td></tr><tr><td id='QUOTE'> The easiest is, as Brian addressed, to use a dark background. However, if that is not possible or feasible, you will need to determine the light output over a series of "pops". From that you will be able to determine lighting ratios. So long as the background is five stops below the lit object the background will render black even if it is in reality snow white. </td></tr></table><span class='postcolor'>
It sounds like I'm going to have to get smarter on lighting. To be honest, I've always trusted my camera to "figure this out" for me. Flashes and artificial lighting have never been my strong suit and I prefer to work with available light. But I've always been fascinated with Edgerton (His book "Stopping Time" is fascinating both as an engineer and a photographer) and am looking forward to trying some of this myself.

I have some nice photography books, but can anybody recommend one that has a good treatment of this subject?