Hello all.

Actually have two topics here.

I have a Zeiss jena DDr 2.8/50mm and a Zeiss Jena DDR 1.8/50mm Pancolar both with M42 thread. One of the sellers of the lens also sells an adapter to fit EOS. I cannot get infinity focus on either lens with this adapter, and when set to infinity with the Pancolar, the mirror hits the back of the lens (as I suspected)
Does anyone have experience of this problem, particularly the lack of infinity focus? Comments much appreciated.

As (I'm told) these are good lenses, which is the best Pentax model (or others) that would suit. I'm a bit shy of trying anything that these lenses were NOT made for after the disappointment of the Canon. Comments much appreciated.

Fidgety

LUCKY YOU!!!

The M42 lenses are of a legendary heritage thanks for Zeiss, and their ultra fine optics. They present some of the best in terms of contrast and sharpness.

Leica was a use user of the M42 before switching to the M39.

All old photographers used these in their range-finders. Cartier-Bresson, Friedlander, Winnograd, all had one of their Leicas.

Here's a list of screw-mount Pentax cameras:

Pentax AP
Pentax K
Pentax S
Pentax S1 / H1
Pentax S1a / H1a
Pentax S2 / H2
Pentax S3 / H3
Pentax SV / H3v
Pentax Spotmatic
Pentax SL
Pentax Spotmatic II
Pentax SP500
Pentax SP1000
Pentax Spotmatic F
Pentax Electro Spotmatic
Pentax ES
Pentax ES II

At one time, even Nikon and Canon used the M42 mount. The Russian Zenit and Zorki both used it as well.

Good job on the find. Its a fantastic lens.

I recommend the Pentax Spotmatic. Its cheap, but it is sturdy and reliable, and will last for a long time.

As for the lack of infinity focus, well, you said it! The lens hits the mirror! The problem is because of the adaptor just converts the mount, but doesn't take into consideration the lens thread that extends to the back. The M42 can have an adapter that works on the Nikon range, as I've used one.

The older SLRs had a deeper body, hence why the lens mount works.

Thanks for all that info!! The 2.8/50mm will not focus to infinity either, although it does not hit the mirror. I am assuming that is because the adapter is the wrong thickness??

Having used EOS with EF lenses, I'm tempted to go back to basics with "Old style"stuff - considering you can buy excellent lenses with no frills at a fraction of the equvalent auto this and that lenses.

Fidgety

If you want to have some fun with these lenses on the 'cheap' ...I think the Zenit cameras take M42 thread, they are very basic, built like a tank, but can produce very reasonable results.

Regards
Steve

Just to correct the completely erroneous information provided by 'Fizz': Leica, Canon and Nikon never produced camera bodies with the M42 mount.

The M42 screw mount was first used on the Contax S, designed before World War 2 by Zeiss Ikon but not released until after the war by the Dresden factory, which was then in the Russian sector of Germany, also known as "East Germany". Edixa in West Germany adopted the mount in the early 'fifties and Pentax some time after.

The following site has a fairly comprehensive list of the camera models that were fitted with this mount: Screw Mount (Praktica/Pentax M42) Cameras

I hope that this clarifies the situation for other readers.

The old Praktica 35mm slr cameras used 42mm thread lenses...that might be another option...not too expensive either!