On Fri, 7 Jun 2002, Richard Martin wrote:
> I understand the basic principle of using the 283 as fill
> flash and I agree completely that the ratio is unpredictable
> using Auto. But how would you do this manually?
Ok... You asked for it !
The quick and dirty method...
If your 283 is putting out a true 2800 BCPS (and some
can go as low as 1400 BCPS...be sure to fire the flash
several times to form the capacitor before doing any work
-or- measurements !). Now, with the unit on full-power/manual,
select the shutter speed, staying at -or below- synch speed.
Set your aperture to match that speed for the ambient
light (for a frontlighted subject, even if your subject
is 1/4 lit or backlit).
The table....(print it out small enough to carry it)
Subject-flash distance in feet. Do not attempt to
use a higher shutter speed than indicated for your
camera.
__________________________________________________________
BCPS 1/30th 1/60th 1/125th 1/250th 1/500th |
----------------------------------------------------------
2800 4-5.5-10 6-8-13 8-11-18 10-14-20 13-18-30 |
----------------------------------------------------------
1400 3-4-7 4-5.5-9 6-8-13 7-10-15 9-13-20 |
----------------------------------------------------------
You will notice three distances given for each
BCPS/shutter speed combo. Using the 1st will yield
a 1:2 lighting ratio (full fill). The 2nd distance
gives a 1:3 (average fill) and the third 1:6 (slight
fill).
This works regardless of film speed !
************************
It also eliminates those pesky calculations.
A few notes:
Since you are stuck with a particular distance
for a given shutter/synch speed, it is easy to see how a zoom
lens can be *very* valuable when working in this manner, enabling
you to crop and recompose without altering your fill ratio.
The value of a higher synch speed for working with fill-flash soon
becomes apparent looking at this chart. If you're using a Leica
with its 1/50th synch, you're quite limited compared to a camera
with a leaf shutter and 1/500th synch. Yes, you can change
shutter speeds (as long as you are at or below synch speed).
One should practice this method and learn just what the different
ratios will look like so they can be pre-visualized. It takes a
little getting used to, but this is quick and accurate.
--- Luis
We can go over the slower way another time. I am tired of typing...
************
*DISCLAIMER* These values are correct to the best of my
************ knowledge, but you are hereby warned that
they may not be, and I assume no liability for your use
of this information. Anyone contemplating using this is
strongly warned that they should test this method on their
own time, NEVER DURING A JOB.
******************
--- Luis
