Just wanted to throw this out for consideration, a letter from a Metz technician. The 'problem' he is referring to is rear sync not working; I use their 58af2 model happily on K7 but it won't play with K5. Nor will 540 or 360. This is what Metz says about Pentax K-5:
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.
The problem is, extreme macro types like myself who don't use standard consumer crap but use specialised optics like a reversed lens, microscope objectives, microfilm lenses or other industrial optics like a JML 21mm now can't and won't use Pentax anymore since the K-5, because rear sync is unavailable when using anything other than modern lenses, even with Pentax' own flashes. K-7 is fine, K-5 useless. What rather baffles me is that the handbook and specifications of the K-5 don't show any change on the big 'flash functionality' chart compared to the K-7 that I also bought. There's nothing that says that you cannot use manual and rear sync. So is this an error on all K-5s? I sure hope so, because if it's not an error then it must be deliberate.
I guess there's a solution though, get a new lens, take the glass out, glue a female K mount on, use it wide open and pretend it's a part of an extension tube. Should trick the K-5 into thinking it's got a new lens mounted. Anyone have a crappy busted thin new lens I could use for this, or am I expected to spend several hundred US dollars to bodge a solution for something nobody asked Pentax to break in the first place?
Mr Angry from England
Last edited by Nass; 11-30-2012 at 06:20 AM.