K10D+M42 lens+SigmaEF530 FP question

[nicholashan]

I brought Sigma EF530 today, but after couple test I found the situation as below

K10D+M42 lens+EF530 ----- M mode，can't FP，shutter speed is limited within 1/180s
K10D+Voigtlander 125mm lens+EF530 ----- M mode，FP(High Speed Sync) ok。
K10D+FA50mm lens+EF530 ----- M mode，FP(High Speed Sync) ok。

looks like this kind of symptom related to M42 lens, don't know is there any one have ever use K10D or K100D+M42 lens+ AF360, AF540 or EF530 can use flash FP(High Speed Sync) function.

is there any way I can use M42 lens with FP or this is the limitation it already know.

Need your help. thanks!
Nicholas.

[Lowell Goudge]

not sure about high speed sync, with non A lenses. My understanding of the K10D (at least my copy) is that with manual lenses all you can do is either manual or "Auto" mode if the flash supports it.

I don't know the Voigtlander 125mm , but the FA50mm will support all flash modes on the K10D

The manual does not acvtually specify the lens types needed for high speed sync

[nicholashan]

so, looks like this is the limitation for M42 lens with high speed sync.

but I don't understand why pentax can't let us input aperture value like the vibration value we input when we use M42 lens for high speed sync.