Flash exposure problem with off-camera studio flash

Has anybody else experimented with studio style off-camera flash and the G2? I've noticed that proper exposure settings don't agree with my flash meter, a Sekonic L-358 .

When shooting either of my film cameras using the same flash units (a couple of Alien Bees for main and fill and a different type above the subject), the proper exposure settings match my what my flash meter says quite closely. I proved this by taking an experimental series of exposures with one of my Nikon F's and a Pentax PZ-10.

However - when I use the G2, I need to stop it down by about two stops below (larger F-stop number) what the flash meter says. I get great exposures, it's just that the camera doesn't like the meter readings.

Anybody have any ideas?

Yep, I agree with you. The small digital cameras do not correlate with "standard" flash metering. Plus it's really easy to get hyper real colors that are not exactly blown out, but still incredibly bright. Thankfully you can just review the image for exposure correction.

I do the same as you, meter, stop down 1, test, adjust flash output, test again, repeat. With studio strobes in particular, I figure that the Canon ISO of 50 is roughly equal to a film ISO of 160.

This can be a real problem. My main two strobes are 640w/s heads, I like to work with the lights very close to the subject. But even at minimum power, it's still too much for a measley F8 on the G2. So I ended up getting a basic 160w/s strobe head, and that works much better (using either a 2x3' softbox or a 9"x36" strip).

D-SLR's do not have this same problem at all. There's a world of difference.

My Alien Bees strobes are 320w/s, and since I'm doing a lot of tabletop work, I also see that I can't stop down enough with the camera. The strobes have a 5-stop turndown, which is quite handy.

My solution is to either turn down the strobes (but then sometimes the balance to my full/half-power-only overhead strobe goes wacky) or to use ND filters. I got a full set to play with. My polarizing filter also works pretty well as a ND.

I'm not alone!!!!!

I think my G2 is off by more than 1 stop, though. I've used my meter with 4 other cameras (2 film, 2 D-SLR) with no problem. The G2 is way off. I just did a test the other day. Meter said 1/125 @ F2.8. Set the camera to that, fired a shot. "Whoa, that's overexposed!" After trial and error I wound up somewhere around 1/500 @ F8.

I don't trust the LCD completely either, so trial and error means flipping back and forth between shooting mode and viewing mode to check histograms. I need to do some more testing to figure out the "actual" ISO, so I can just adjust my meter's ISO setting and be done with it.

On the up-side, I shot over 200 frames the past 2 days and it didn't cost me a penny

My experimentation shows about a 2-stop difference between my flash meter and the required settings on the G2 to achieve good exposures with my studio flash rig. It's as if the G2, when set to ISO-50, is close to ISO-200. This is apparently only true with external flash, as the conventional light readings seem to be close. I too need to do some more experimentation.

I am going to get a lot of use out of the neutral density filters I bought to use with my G2 (and they fit my Pentax as well - 58mm threads).

2 stops sounds pretty accurate.

The ND filter idea is brilliantly simple. Great idea. Thanks guys.

Jon