Is trailing curtain sync with manual power settings possible with Metz flashes on Pentax?

Question

I want to use manual flash power settings in combination with trailing sync with older manual non-smc (m42) lenses on a Pentax K-7.

This is for extreme macro and focus stacking. I'm using microscope lenses and adapters, hence it's M42 mount, with no electronic connection. I need trailing flash because I mix ambient and flash but need to eliminate flash ghosting. I believe only Metz 58 AF-1 or 48 AF-1 models will work? I have found out that I can actually get a trailing pop with a Pentax AF360FGZ flash mounted, but because the lens is non-A, it will only do 100% flash power every pop, which is no good for me because the flash won't last several hundred shots.

Can anyone confirm that the Metz 58 will let you set the power output on a Pentax trailing sync shot using non-a lenses?

Answer 1

My experiments with K-5 and K100d Super show that yes, you can certainly set it up this way; it may or might not work that way.

I tried it out with a Pentax K-5 (firmware 1.01, repeated after upgrade to 1.13 - most recent), Metz 58AF-1 (firmware v3.0 - most recent), and Lensbaby (as manual as a lens can get). This combination can be set up in the described way; the flash will pop in the end of exposure at the set level. However, it seems that the pop comes just a tad late (after rear curtain closes), so the light from flash will not actually be caught by sensor. I tried several shutter speeds from 1/4 to 4 seconds, but was able to catch some flash only after switching off rear curtain sync.

EDIT: I did the same experiment using K100D Super (firmware 1.00) instead of K-5, and it worked flawlessly. So the mistiming could be limited to (my) K-5.

So it might work using a K-7, the newer 58AF-2 and/or some future firmware version.