Re: Fill Flash w/ Metz & M6 - More

[David Seifert <dseifert@earthlink.net>]

At 10:46 AM 8/7/97 -0400, Kermit_Daniel@monitor.com wrote:
>

>I just read Richard Hemingway's reply to my M6/fill flash question (Thanks)
>and I want to check that I'm thinking about this right.  Everything he
>wrote makes sense to me, but I was thinking about it a little differently.
>I've been thinking about the M6's slow sync speed as a limit on useable
>film speeds --- it limits me to slow film outside.  I've been thinking
>about the fill-flash possibilities this way: Most of my lenses have a
>smallest aperture of f16, so what is the film speed that will give a
>correct exposure at f16 and 1/60th sec. under the lighting conditions for
>which I will want fill-flash?  That is the fastest film I can use if I want
>fill-flash.  Based on the "sunny 16" rule that means Kodachrome 64 or
>Pan-X.   I can live with that.  

Well, no I don't think you can.  If the correct exposure for natural
lighting is f16 @ 1/60 and you can't up the shutter speed you will not be
able to increase the lighting ratio with the flash.  You are already at the
limits of your system to limit the light hitting the film.  What you would
really want to do is set the aperture to f32, tell the flash that you are
using f32 (if it allowed that, I think f16 may be the limit for the Metz
unit) and you would then get a nice 2:1 fill flash ratio.  To make this work
you would need to use an ISO 32 or slower film to make this work.

[snip]

>I would like some real information from anyone
>who has used the internal fill-flash features of a Metz (or any other
>brand; Metz is the only one I know of that offers units that calculate fill
>flash themselves).

It is important to remember that flash units alone (Metz or other brand) do
NOT calculate fill flash.  They use a simple reflected light meter to
determine when to extinguish the flash tube.  They determine this by using
the film speed and f stop you have dialed in to the flash.  They assume the
ambient light is NOT a significant factor and expose for the dominant light
reflecting surface.

Fill flash can only be calculated automatically with the cooperation of a
camera which can alter its exposure setting to take into account the ambient
light.  The automatic part of the process is that they will alter the
exposure setting to keep the flash illumination/natural illumination ratio
within the desired range.  

Hope this helps.

David Seifert