beginner studio flash question

[Dan Dozer]

I feel like such a beginner asking this question and I'm sure that there is a fairly simple answer for it. I have recently wanted to try indoor flash photography and have gotten my hands on a couple of studio soft boxes and a Sekonic flash meter. I've been reading the light meter instructions but there is something that I just don't get.

I'll be working with 8 x 10 black and white film. I can adjust the intensity of the flashes manually. I can sinc them together to all flash at the same time with slave triggers. While one or two of the lenses I'll be using have shutters with sinc cord connections on them, others are barrel lenses with Packard shutters so they will not be sinced to the flashes. My thought was to set everything up, darken the room, pull the dark slide, pop the flashes, and replace the dark slide. With that scenario, all I'm worrying about is the film speed, and balancing the light intensity with the F-stop. Am I wrong here?

My confusion is with the meter becuase it gives both the F-stop and shutter speed. With the flash duration extremely short, what difference does it make what the shutter speed is as long as it's longer than the duration of the flash, and if that's the case, what shutter speed do I set the meter at to get an accurate reading for the F-stop?

Any advice on how to set everything up would be greatly appreciated.

 

[David A. Goldfarb]

What you're describing is "open flash" technique, which works fine. Usually the strobes are at least five stops above ambient with normal room light on, so you can even in that situation have a half-second or one second ambient exposure without any effect.

I don't know that particular meter, but with most flash meters, it doesn't matter what you set the shutter speed at when you're reading in flash mode. Test it out by taking flash readings at different shutter speeds, and see if it changes the reading.

 

[Nick Zentena]

The fancier Sekonrics only care about the shutter speed for balancing ambient light. They'll give you a percentage of how much of the exposure is flash. But in the situation you describe [dark room flash] there is no ambient to worry about. If the meter does do balancing set the shutter speed slow say 1 second and see how it reads. Or the flipside set the flash to real low power and take a reading.

I guess you've got the packards without flash sync?

 

[David A. Goldfarb]

If you're using the Packard without sync, what I've done is to hold the bulb in one hand and the meter attached to the strobes in the other. Pull the darkslide, open shutter, fire strobes, close shutter, replace darkslide. You can get the exposure pretty short this way.

 

[Dan Dozer]

So, I think I understand it. If I set the meter to a shutter speed for one second, for example, and the meter reading says that the flash fills in 90% of the light, that means that the ambiant light is the other 10%. The shutter speed of one second actually only applies to the amibient light. In this case, the ambient light is fairly minimal and won't even affect the final image much at all.

In answer to Nick's question, no my packard shutter doesn't have the sync. The flash meter I have is the Sekonic L-358.

 

[Nick Zentena]

Yup you've got it right. If you change the shutter speed to a shorter one at some point the reading will be 100% flash. Or if you increase the flash power same thing.