RE: homemade gray card,

I made a target out of brown cardboard that worked well
enough, thanks for all the suggestions.


In case theres any of you looking for alternative techniques
and dont happen to do things my way, heres how I do flash
macro.

I use the camera on manual flash full power, iso200, max
sync speed (1/180). This is with the *istds.

What I do everytime I get or use a macro lens for the first
time is run an exposure test using different fstops at fixed
magnifications.

i.e. I shoot 1:2 magnification at F32,22,16,11,8,etc
and determine and record the best fstop for that magnification.

then do same thing at magnification 1:3, 1:4 etc.

what I end up with is a chart that tells me the best fstop
for each magnification.
========================================================================
=====================
In this case, with the SMC-M 50mm f4.0 lens I got

MAG     Fstop (best)
1:2     overexpsoses, out of fstop range
1:4     F32
1:8     F22
1:12    F16
1:16    F11

Now all I do is save the chart until I memorize it via
repeated usage and I never have to fool around with my
macro exposures, this saves a LOT of time.

What I do is select a magnification to use based on
the size of the object/target, set the fstop per the
chart I created, and instead of focusing the lens to 
the target, I move the camera in and out while leaving
the focus/magnification fixed as selected. The reason
I do this is because if you focus the lens you are changing
the effective fstop, by not focusing the lens, this variation is
eliminated.

I get beautiful consistant MACRO WITH FLASH exposures this way, very
fast, and very easy.
(warning - the fstops table for this lens looks like some sort of
mathematical sequence,
its not, its just conincidence in this case. with a 100mm lens you get a
totally different sequence)

JC O'Connell
[email protected]
 



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