M42 Adapter, help!

I agree with you Kim, in terms of usability the A lenses work best, and I think K and M series lenses are best avoided for DSLRs. But... there is something delightfully tactile about SMC Taks, they just feel so much nicer to use than anything current. I think the prices are high (often higher in numeric terms than they were thirty years ago) because there is a collector's market for them. I don't think there is a collector's market for bayonet mount lenses - yet.

Ken

At one stage, the M42's were very cheap and a bargain. With the advent of the DSLR and change in mount especially for the Canon, they started to be sought after by other users using M42. The early K lenses are for the most part identical except they have the K mount and a rubber grip. The action on them is as smooth as the Taks. I have always fond the A to feel a little plasticky and as I generally used the LX avoided them apart from such as the 20/2.8, 15 and a couple of zooms.. It was only when I got the D and now the K10 that I have managed to build a good selection of the longer primes.

Kim

Thanks, apparently it needs one more step. After doing some searches I found the following. The K100D uses some of the contacts to determine the min and max aperture of the lens and it does this by measuring whether there is an electrical contact with the lens. Apparently an M lens has just bare metal (can someone confirm this?), so all the contacts will short. In my case the contacts touch the painted face of the M42 lens and the K100D does not ask for the focal length even though it cannot get this any other way. After some searches I've found that a fix is to short the contacts using some aluminium foil, and I have found that this does work, the camera now asks for the focal length when I switch it on.

Richard

As far as I am aware, all Pentax (and clone) bayonet mount lenses have a chromed surface that mates with a similar chromed surface on the K mount camera bodies. All lenses and bodies from A series onwards also have a varying number of electrical contacts.

This problem sounds identical to an issue (documented in these forums) I had some time ago with a set of Jessops extension tubes. Although they were 'A' series compatible, they had only 6 or 7 contacts. The *istDS body I had at the time had one more contact than the tubes. The remaining contact surface was painted (insulated) and I had to scrape some of the paint off of these tubes to get the DS to function. Others here have employed the same remedy to good effect.

I think the same seems to be true of some/all screw lenses. Your aluminium foil idea would seem to work OK, the alternative would be to remove the paint from the body mounting surface of the lens. If its actually anadized, rather than painted, that might be a problem.

I've used a variety of old lenses on my K10D in M42 and M39 fit. Some work well, some don't.

I was using the Kood M42 to PK adapter fairly successfully until I got a macro bellows unit stuck on ( I couldn't unscrew from the adapter as the top of the bellows fouled the flash ) I then couldn't get the Kood adapter to unmount either. Using brute force and ignorance I broke the retaining spring and got it off eventually. No damage to the camera - phew!

I then bought the official Pentax M42 to PK adapter and wish I had from day one. Such a pleasure to use in comparison to the Kood.

Anyway back to the point of my post:

I unscrew the lens from the adapter. Then when removing the adapter I press the lens release button on the body, just as if it was a regular lens, then twist the adapter and lift it out (both on the Kood and the Pentax variant).

I've encountered a few people who didn't press the lens release button, then jamming the Kood adpater and breaking the spring off...

Umm, I just read this, it does not seem right.

When I press the lens release button on my K100D the only things I see moving are the locking pin (between 8 and 9 o'clock looking into the camera) and the AF motor coupler (at about 4 o'clock). I looked inside the mount as I pressed the button and didn't see anything else move.

So that would suggest that the lens release button has nothing to do with releasing an M42 adapter. Can anyone confirm this?

Richard

The lens release button has no effect on removing a Pentax Adapter K. Maybe it would be relevant with some other design of adapter, although I would have thought such a design could prevent infinity focus unless it incorporated lens elements.

Does the Kood adapter have lens elements?

The correct procedure is to screw the adaptor onto the lens, then bayonet the lens on to the body. To remove, unscrew the lens from the body and then remove the adaptor from the body by depressing the spring on the adaptor and turning it counter clockwise and pulling it out.

Oh well it certainly made the removal of the Kood adapter much easier for me. Even when holding in the spring it wouldn't fully disengage, but with the spring in and the lens release button depressed it would.

Perhaps because there is less friction with the pin retracted.

Kim

It is fairly easy to modify the M42 adapter so they work more like the K-mount if you want to leave an adapter on the lens all the time.

http://www.rangefinderforum.com/forums/showthread.php?p=665743#post665743

Kim

I then bought the official Pentax M42 to PK adapter and wish I had from day one. Such a pleasure to use in comparison to the Kood.

Is there an online source (other than Ebay and preferably in the UK) where I could get one of these? I've bought a few M42 lenses recently bu the crappy adapator I have doesn't allow infinity focus.

Why not try here!
https://www.pentaxuser.com/pages/pl_2007.html
£20 or £18 for members.

Kim

SRS do them.

From what is written further up this thread I get the impression that any which require the use of the lens release button wont allow infinity focus. Pentax ones sit flush within the K mount