Question on exposure with flashgun

[arbageddon]

Hi, i'm using an E520 with a Metz-48, i have the following scenario which leaves me wonder how the camera/flashgun determine the correct exposure:

1. Camera on aperture priority, ISO100, lense at F4, flashgun on TTL mode and pointing 45 degree with diffuser on, +0.3 EV on flash... Camera reports recommended exposure of 1/30 second.
2. 1/30 second should be the slowest the flash can sync normally. And the picture comes up slightly underexpose. So i raise the ISO to 200, 400... Finally got it right with ISO 400, F4, 1/30 second with the same flash settings.
3. I expect assuming the ISO and aperture stays the same, when i raise the ISO to 800 and 1600 i should get exposure of 1/60 and 1/120 respectively. But this is not the case, i'm still stuck at 1/30.

Is there anything wrong with my camera/flash, or its just my poor understanding on how to use the flash properly.


Thanks.

[red]

TTL works in mysterious ways, especially with 3rd party flash. to test, best use manual mode altogether.

sounds like you already at the full power of the flash at ISO400.

[simplyrobin]

I think it has something to do with your sync speed limit setting. Try setting it higher to 1/180 sec (limit) from the in-camera setting. Usually when I turn to Aperture priority on my FL36R, it will automatically meter to 1/180 seconds regardless the TTL adjustments.

Nonetheless, I shoot manual on flash, so that issue is overriden.

[mfahrur]

Shutter speed with flash... there are 3 things you should know...

1. X sync
2. FP sync
3. Slow curtain sync.


X sync is usually the low and high range in the shutter sync range.
for oly, it's between 1/30s to 1/180s. At these range, the shutter speed don't matter. What matter is the ISO and A.

FP Sync if for high shutter speed so that there's no shutter blackout.
This will impact exposure especially ISO.

Slow curtain is for shutter range 1/2s to 1/15s.
This setting is sensitive with all ISO, A & s.


Good luck.

[Urs]

TTL works in mysterious ways, especially with 3rd party flash. to test, best use manual mode altogether.

sounds like you already at the full power of the flash at ISO400.

As possibly most of you all know I only use Metz flash. My wife use the Metz 48 with E510 and her setting always is manual e.g. exactly what red recommended.

I use the Metz 58 with E-3 most of the time in A-mode to have complete control over DOF. In some cases I also use manual mode.

ISO is important for sure, indoor I generally set at 400 not higher, sometimes depending the available light a bit lower, outdoor it is most of the time at 100 or 200 with flash.

Shutter speed in flash mode I have set at 1/180 for 510 and 1/250 for E-3, what works perfectly for us so far. In some cases we may change the speed, but that is very seldom.

We have tried TTL - before buying Metz we briefly used respectively tested FL36 - but the result were not to our liking at all. The TTL setting worked for us only for limited scenarios, so we do not use it at all anymore.

Alll pix you see in my FB or TE galleries are shot with Metz in either manual or A-mode. See for yourself.

I hope this explanations help.