[Nass]

Hello,

Just documenting this here in the hope that either Pentax fixes this or that it prevents anyone else from trying to figure out why this doesn't work. The problem is manual lenses.

A typical rear curtain shoot for me might be 2s manual exposure with Metz 58-II on rear curtain set at 1/32. This combines ambient and flash for me; it has to be on manual because I use all sorts of weird and wonderful non-camera lenses like microscope objectives etc. Rear curtain sync is crucual, it prevents something called "flash ghosting". This setup works perfectly well on the Pentax K-7.

It won't work on your K-5. Bottom line, K-5 won't do rear sync on manual lenses. I've had this confirmed from Metz where I initially reported it as a bug. Fyi, email from Metz:

Meanwhile I got the Pentax K-5. The camera is loaded with the firmware version 1.13. I use the standard AF lens 1:3.5-5.6/18-55 mm and also the manual lens 1:1.4/50 mm. The camera is set in manual mode "M" with shutter speed 2 sec.

The Metz flash unit is set in manual-flash-mode "M" with a partial light output 1/32. The rear function is ON. In this case I also could realise the problem but only if the manual lens is used. If the AF-lens is used the combination works. If I use the Pentax K-7 it works with both lenses.

Therefore I also checked it with the Pentax flash unit AF-540FGZ. If this flash unit is used in rear function with the Pentax K-5 and the manual lens the flash unit will not work. However, if the rear function is switched off the flash unit will fire with full light output. The Pentax flash unit fires with full power together with the Pentax K-7 as well as manual lens with and without rear function. Therefore the Pentax flash unit doesn't enable the P-TTL-flash-mode if the camera is equipped with a manual lens.

Obviously the problem in rear function with manual lenses is caused by the Pentax K-5. In this case the Metz flash unit as well as the Pentax flash unit will not be triggered correctly. This is why we can't remove the problem by a new firmware for the Metz flash unit. Maybe you should contact company Pentax or you should use AF-lenses in this case.

Fyi I've lodged this with Pentax as a bug, I'll repost if I get a response.

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Last edited by Nass; 10-31-2012 at 11:56 AM.