M42 lenses on *ist-DS

I have an M42-K adapter that I bought to use my old M42 lenses on my *ist-DS. But I am a bit frightened because of my first experiments.

The adapter does not have the spring to lock it in place, wich is kind of good for me since I can remove the lens as if it was a normal K (though it does not lock on the mount). Funny thing is I cannot mount my auto/manual Helios 58mm. I feared the auto pin might be touching inside the DS' chamber somewhere, but after measuring the pin and the adapter it seems it does not reach far enough to touch anything.

Nevertheless, the lens does not mount easily. First, I tried to mount the adapter and then screw the lens in, and it feels like it really is touching something along the way. Then, I tried to mount the lens on the adpter and the set on the body, but it doesn't seem to fit neatly on the body mount, let alone rotate...

Has anyone mounted an auto M42 lens (with the auto pin sticking out) on the DS (or any other K-mount body) sucessfully?

Thanks!

Hi Flink,
Many of the FSU cameras and lenses were built to a different standard although they used the same threads. This is a particular problem with the Leica thread lenses where many will not fit on Leicas, Canons, Voightlanders etc because the lens body protruded too much into the camera body. I rather suspect that is the case here. The M42 thread was not all that universal! Even within the Pentax system there were incompatibilities. The F1.4's couldn't be used with the earlier bodies and some of the early Super Taks could damage the Spotmatics because of the way the stop down pin worked. Most of the SMC lenses can't be used on other bodies because of the extra Auto/Man pin etc, etc.

I don't know which Helios lens you are trying to use but to be honest, I wouldn't bother. The Pentax M42 lenses were superb quality and can give a much better image than many modern zooms. I certainly wouldn't say the same for the FSU ones! In this case, you are likely to get better quality from a good modern zoom and keep all the functions. There isn't much gain in speed either.

Kim

The way the adpater is designed to work is that you first screw it onto the back of your lens. Then you bayonet the whole thing into the camera body. When you unscrew the lens the adapter will stay behind, thus effectively from then onwards turning the bayonet body into a screw mount body. Screw fit lenses can then be inserted and removed as desired.

When you want to remove the K adapter, use a small pointed device (screwdriver, pen...)to depress the small clip thus allowing the adapter to be removed.

It is not terrific in that only stop down metering can be used, but it does work. I wouldn't be very happy if the clip was missing on the adapter as the whole lens just might come adrift at some point, and it would be a bit of a nuisance to keep checking it was seated properly.

I've reached the conclusion that by and large I use the appropriate lenses on the appropriate bodies - this is what they are designed for and the ergonomics are sound.

Having said that, the screw mount lenses do work pretty well on the digital bdies, IMHO better than the K and M lenses do because they cause less messing about to be needed. I know some of us don't agree on this!