>some time ago you wrote me that I could do exposure corrections when
>using TTL flash on an F3 with the AS-7.
>I have the AS-7 now, and wonder if the correction on the F3 itself
>still works (the +/- 21 stops thing) Or does it only work if I correct
>the asa setting on the AS-7 ???
>J.J.Aue@phys.RUG.NL (Jan-jaap Aue)

Hi-- When using the AS-7 (or a remote cord) with a flash, only the ASA
ring on the AS-7 (or remote cord) controls the flash. The ASA ring and
the +/- compensation ring on the F3 do not change the flash TTL exposure
when the flash is off the camera shoe - just the ambient-light camera
meter. If you want to set up a TTL flash-fill ratio, here is an example:
If you use 100 ASA film and want no compensation for the available-light metering, but want a 1 1/3rd stop TTL fill ratio, set the camera at 100
ASA, the compensation at 0, and the AS-7 ASA ring to 250 ASA. (You cannot
set the flash ASA higher than 400. If you leave the flash on the F3 shoe
and set it at 400 and add compensation that makes it actually higher, you
will get the blinking error signal.) If you want to keep the camera ambient-light meter on while the flash is on, cover the middle contact on
the shoe with a bit of tape - but you will lose the ready light in the
viewfinder, --> and it will be possible to set shutter speeds above the
synch. speed (keep track of the shutter speed!). BTW, I am STILL working on that lens-checking article.....!!!! David Ruether