adapter for M42

Hi!
I got couple prime lenses with M42 mount. I can't focus on infinity, therefore, it is the fault of the adapter.
those adapters are different, or that will be with all?

If your adapter has a flange that extends beyound the threads, then it acts like a very short extension tube and you'll loose infinity.
The actual Pentax adapter sits flush inside the opening (you use an actual tool to insert it and remove it) and infinity focus is maintained.
It costs quite a lot more than the first kind.
If you can find it get it.
Those M42 lenses are amazing.

The Pentax Adapter K is still available new.

The technique is to attach the adapter to a screw thread lens and then bayonet it onto the camera. That lens can be unscrewed and replaced as desired, effectively turning the body into a screw thread one.

When we want to remove the Adapter K a small catch has to be released with a small tool sometimes provided or the tip of a pen or mini screwdriver. The adapter can then be gently rotated and dropped out into the palm of the hand.

All clear! thanks!

I spent quite some time trying to win one of these on ebay then gave up and bought one from, guess who, our friends at SRS...

K.

Does this mean that it's a slow process to change back to K mount and not recommended "in the field"????

I have fancied a 400mm lens for a while and have thought about a screw mount but might change my mind now, especially in view of another of JR's comments ie it's better to crop from a 55-300.

Cheers,



Howard

I wouldn't bother to mix K batonet and screw mount lenses on one camera body, but if I had lots of screw thread lenses I might use a dedicated body with an adapter more or less permanently attached.

Swapping about in the field would be slower than just using K mount lenses, or screw thread lenses, and mixing seems a bit inconvenient. Unless you feel you really want to do that.

I have seen instructions for converting M42 lenses to K mount with a cheap adapter. Basically it entails removing the clips from the adapter, fitting it to the lens, and drilling a small dimple to allow the locking pin on the camera body to function as it would with a K lens.

This also removes the other problem with some cheap adapters - the clips can become worn and jam in the camera body. No clips, nothing to jam!

It is a little fiddly but not too much of a pain depending on circumstances. I mainly use it to use my Jupiter 85mm as I do not have a k-mount lens like it. As that is a preset lens it is a bit fiddly to use anyway. The other time I use it is with my bellows as I do not have a k-mount set of bellows and the 50mm Taks I have work well with it.

For a 400mm lens you are probably better off using the 55-300 and cropping as John suggested although mounting a 400mm Tak will get you noticed!

Best wishes, Kris.

Thanks everybody for your good advice. I'll stick to cropping for now and save my pennies for something else.



Cheers,

Howard

And the price has just gone up from £22 to £65

Since when? When I looked at the price list on PU yesterday it was just under £20 from SRS.

I have three M42 adaptors. An original Pentax which is the best but expensive; a Chinese sourced similar design from which I unscrewed the metal clips to be on the safe side. It's a lot cheaper and works fine. A third and cheapest adaptor is the type with a wide flange. I usually leave this on a Helios 44M used for wild flower photos where lack of infinity focus is not an issue. Handy if interchanging the Helios with K mount lenses.
bb2

Since I don't know - I got one a few weeks back for £22. I don't know what PU is. But, unless I've got the wrong end of the stick:

http://www.srsmicrosystems.co.uk/156/Pentax-Mount-Adapter-K.html

Wow! That's a high price I have to admit. It may be that the Pentax User price hasn't been updated - see Shop>Price List at the top of this page.