[shaolen]

Is there anything I should know before using an adapter for m39 to K-mount? Like is it impossible to remove?

[ppohja]

Here is the picture of my copy of the mentioned adapter. The m39 flange distance is actually smaller than the Pentax K-mount or M42 (45.2mm vs 45.46), but still this adapter extrudes a bit out of the mount. Therefore there is no problem in removing the adapter.

In my use the biggest problem is that the attached lens ends upside down to the camera.

[Not a Number]

I bought an adapter ring from Fotodiox that fits into the M42 adapter (M42 to M39 adapter ring). Note it will not thread into the Philippines made adapter but fits fine into the Japan made ones (and Asahi Pentax screwmount bellows and SLR bodies).

[ppohja]

Yeah, I had that one too. It was cumbersome to have these small and tiny adapters, sticking to each other.. So the adapter in the above picture appeared from ebay.

[Audi 5 cyl]

If you use a flanged adapter you will lose infinity so I would advise you to get a m39 to m42 adapter and m42 to pk non-flanged adapter. I use that setup and I've never had issues with infinity or removing.

Further, it is important to know if your lens is actually ok to use on pentax cameras. There are many lenses out there in Leica m39 flange focal distance. Those can not be used on Pentax cameras, except for macro.

Regards,

Marko

[Not a Number]

I've never had problems installing or removing the ring except with the above mentioned Philippines made Pentax branded adapter. Sure it's a bit fiddly but no more than adding a reverse or setup/down ring or filter. If the extra 3-10 seconds is too much time for you why are you bothering with a manual focus, manual stop down screw mount lens in the first place? In my experience the ring usually stays in the camera side when you unscrew the lens.

The adapter rings means I can use it on other mount M42 adapters, screw mount bodies and my screw-mount bellows. The main reason I bought the ring was to use enlarger lenses on my bellows (typically M39 threaded) both screw mount and Minolta mount - a Minolta to M39 was difficult to find at the time I bought the ring.

Note: If you use a non-conductive adapter ring as illustrated the green button or Av mode may not work unless you remove some the coating over the "data" pin contact. A bare metal version may be better.