Archived posting to the Leica Users Group, 2002/07/09

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] Bouncing with the SF20 (long)
From: "Frank Filippone" <red735i@earthlink.net>
Date: Tue, 9 Jul 2002 03:21:16 -0700

Fill flash is hardly a "fast" flash.  Is usually is set up such that the
flash proportion is pretty close to the ambient light.. maybe a stop or 2
below, but still, pretty close.  That means the the ambient light is pretty
close to F stop  @ 1/50 of a second.  Therefore you get movement artifacts
at 135mm as the ambient light is making a major inpact on the exposed film..

Try again, using the head on flash, in the dark.  Now the ambient light
required maybe 5-6-7 F stops more open.  The flash is providing the majority
of the light to the film.  The flash will be putting out light at maybe
1/10,000 of a second.  It freezes the action.

Yes, you still have SOME residual ambient light hitting the film, but it is
proportionally much less than the flash light.  It does provide some
"movement" of the subject, but it is approximately "averaged" with the
flash.  At 5 stops away, the movement is providing 1/32 of the total hitting
the film.  So small that you can not fuind it easily, and therefore the
action is stopped, and the picture looks like it was taken with less
movement of the subject or a higher shutter speed, especially important with
the 135mm focal length..

Going back to the SF20 flash....   If you wish to improve the movement of
the 135 lens in the shot, you need a flash that provides MUCH more light
output, and give up on fill flash.  Then you will be
1) shooting at a smaller F Stop, which helps with DOF
2) decreasing the ambient light component of the action ( this provides a
darker background compared to the face which may NOT be what is desired)
3) provide the flash with an even faster flash duration, say 1/100,000 of a
second that freezes the action more than 1/1,000 of a second

I think I have overkilled this answer, but to add to the overkill more....
My Honeywell 780 potato masher flash puts out so much light, that the high
movement of indoor basketball players is totally arrested by the fast flash
speed and low ambient light component, when taken at 1/125 of a second at F8
on my old Contax RF camera.  But fill flash it is not.  It could have been
set for bounce flash in the original picture, with some loss of light, but
it STILL would have worked, albeit manual flash mode.  The issue is the
strength of the flash tube.  The SF20 is pretty meek.  My old potato flasher
is really strong.  You would need a modern Metz 45 or better, 60 series
flash to be totally integrated with the M6 TTL sensor.  Does anyone know if
the M6TTL will work with the Metz 45 of 60 series potato mashers?  Which
model numbers, which "adapter" model numbers?

Or use a tripod with the original set up.  KISS.

Frank Filippone
red735i@earthlink.net


- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html

Replies: Reply from Mark Rabiner <mark@markrabiner.com> (Re: [Leica] Bouncing with the SF20 (long))