Flash questions using Mamiya 645AF and Metz 40 MZ-3i

[edward_c._nemergut]

I have recently upgraded my medium format system from a C33Of to a

645AF and I have some questions regarding the use of flash with my new

camera.

 

1) When is the camera using the flash as fill and when is it not?

 

 

In general, I like to take indoor portraits (at a wedding, for

example) using NPH at 1/60 and f/5.6 with the flash as the primary

light source. With my old C330f and Vivitar 285, I would make these

setting on the lens, and then adjust my flash output manually. Fairly

simple and it worked well. With my 645AF, SCA 3951, and Metz 40 MZ-3i

in TTL mode, I'm not sure how to accomplish this simple task. For

example, if I set my 645AF to "Av" mode and select f/5.6,

it gives me a shutter speed of something like 1/2 (and vice versa).

To me, this suggests that the camera is metering the incident light

and planning to use the flash (turned on, in TTL mode) as fill. Is

this true? I think this is the way my Canon system works (although I

obviously don't use it for outdoor wedding portraits).

 

One solution is to select 1/60 and f/5.6 in "M" mode; however, when I

do this the camera tells me how much I'm underexposing the scene (-6.0

flashes in the viewfinder) and I wonder whether the camera will then

use the flash as the primary light source as I intend or if it will

just figure I don't know what I'm doing and underexpose the scene.

 

An obvious solution is the "X" mode where I can select f/5.6 but the

shutter speed is fixed at 1/125 (too fast, in my opinion); however, I

wonder if this is the only "mode" where the camera will allow me to

use the flash as the primary light source.

 

So, to make a long story short, when I go to my next wedding, what

"mode" do I need to use to operate the camera and flash as I do my

C330f (1/60, f/5.6 primary light source as flash).

 

I suppose I could just go back to doing the whole thing manually, but

that at least partially defeats the purpose of the new 645Af and Metz

40 MZ-3i purchases.

 

2) Is it possible to adjust flash output in TTL mode?

 

Assuming someone is able to explain to me in #1 when I'm using fill

flash and when I'm not, I'd also like to know how to adjust to amount

fill in TTL mode.

 

Back on the C330f, if I wanted to take a portrait at an outdoor

wedding and use my flash for fill, I would meter the existing

light--say 1/125 and f/5.6--and then manually adjust my flash output

to f/4 (for -1.0) or f/2.0 (for -3.0) and so on. Again, this was

simple and worked well. On the 645AF, I have attempted the same

procedure in

TTL mode and have had trouble. For some reason, the f/5.6 aperture

seems to be somehow "locked in" and can't be changed. (I also tried

to trick it by changing the film speed on the flash but it also seems

to be locked in TTL mode). Strangely, if I change to "A" mode

(automatic, I guess) on the flash I'm able to make these changes. So,

is it impossible to adjust the amount of fill in TTL mode?

 

Again, I suppose I could just do the whole thing manually ("M" mode)

but, of course, I don't understand why I paid all that money for a TTL

capable camera and flash...

 

All comments appreciated...

[mark_shaw2]

Edward,

 

Check out this link:

 

 

http://www.photo.net/bboard/q-and-a-fetch-msg.tcl?msg_id=0012O4&topic_id=35&topic=Medium%20Format%20Digest

 

 

There was a long disscussion on this topic a few months ago.

 

Hope it helps.

 

Mark