Why does the screw-mount exist?

[RJBender]

I think m42 screw mount with good adapters is a great way to get into some good lenses.

I have a cheap K-mount SLR, and 2 amazing m42 lenses, a Sigma 18mm 3.4, and a Vivitar 35 f1.9 that share an m42 to k adapter which stays on the body (I hope these are my last lenses for this slr ... ).

But to my point, to have bought these quality of lenses in k-mount, if they even exist, would have cost much much more.

Also, in researching these lens, I have found folks are using these (with appropriate adapters) to good use on even their DSLR's. It's great glass, just on an old funky platform, which is why these adapters are so important.

I'm using a 85mm Jupiter 9 (M42); 58mm Helios 44 (M42); 35mm Distagon (Rollei QBM); 50mm f/1.4 Planar (Rollei QBM) and all my Nikon MF lenses on a Canon EOS A2 with adapters from China. I want to see if I like the results before I buy a Canon D20 or D30.

R.J.

 

[bmattock]

I agree with Walker. The best 50mm lens I've ever owned, and by a lot, is a Pentax Super-Multi-Coated 50mm f/1.4 in M42 mount. And fortunately, there are M42->everything adapters. I like the M42 lenses enough that I bought (a couple of years ago) a Bessaflex TM from Stephen Gandy. I wanted a new platform with modern TTL metering for my M42 lenses. I also use them on my Pentax *ist DS.

Like Walker, I've never cross-threaded one. However, while trying to mount one while not looking, I've gone round and round and round and so - never quite 'catching' to begin the wind on. And I've come close to dropping a lens once or twice - never actually done it yet, though.

And as a final note - nobody has noted the 'best' mount system - the Canon FD breech-mount.

Best Regards,

Bill Mattocks

 

[Fedzilla_Bob]

And as a final note - nobody has noted the 'best' mount system - the Canon FD breech-mount.

Best Regards,

Bill Mattocks

Amen Brother! Can I get an Amen?

I am keeping my FD Glass.

 

[doubs43]

And as a final note - nobody has noted the 'best' mount system - the Canon FD breech-mount. Best Regards, Bill Mattocks

The beauty of the breech-lock system is that the mating surfaces remain constant while any minute wear on the surfaces that rub are automatically compensated for by tightening the collar just a wee bit more. IOW, wear is self-correcting and the mount remains solidly locked.

I've often wondered why an interrupted thread mount, similar to an artillery breech, has never been tried. Maybe it would require too much machining.

Walker

 

[bmattock]

The beauty of the breech-lock system is that the mating surfaces remain constant while any minute wear on the surfaces that rub are automatically compensated for by tightening the collar just a wee bit more. IOW, wear is self-correcting and the mount remains solidly locked.

I've often wondered why an interrupted thread mount, similar to an artillery breech, has never been tried. Maybe it would require too much machining.

Walker

I believe the ill-fated ultra-rare Ilford Witness, a stunningly beautiful camera, had such a lens mount.

http://website.lineone.net/~mauricefisher/Witness.html

Best Regards,

Bill Mattocks

 

[ampguy]

Cool

Cool

Here's a link of a French photographer using a bunch of m42 lenses. Many of the images were taken with a canon digital, I think D10:

http://emmanuel.correia.free.fr/m42.htm

I'm using a 85mm Jupiter 9 (M42); 58mm Helios 44 (M42); 35mm Distagon (Rollei QBM); 50mm f/1.4 Planar (Rollei QBM) and all my Nikon MF lenses on a Canon EOS A2 with adapters from China. I want to see if I like the results before I buy a Canon D20 or D30.

R.J.

 

[David Murphy]

I agree with Walker. The best 50mm lens I've ever owned, and by a lot, is a Pentax Super-Multi-Coated 50mm f/1.4 in M42 mount. And fortunately, there are M42->everything adapters. I like the M42 lenses enough that I bought (a couple of years ago) a Bessaflex TM from Stephen Gandy. I wanted a new platform with modern TTL metering for my M42 lenses. I also use them on my Pentax *ist DS.

Like Walker, I've never cross-threaded one. However, while trying to mount one while not looking, I've gone round and round and round and so - never quite 'catching' to begin the wind on. And I've come close to dropping a lens once or twice - never actually done it yet, though.

And as a final note - nobody has noted the 'best' mount system - the Canon FD breech-mount.

Best Regards,

Bill Mattocks

I agree, the 50mm F1.4 Tak is an insanely good lens -- much better than it has a right to be considering it harkens from an earlier era. As someone with a background in optical design I am amazed that such a good optic was mass produced in the early sixties by a country still struggling to resurrect its high tech industry. I suspect the Takumar lenses probably represent the first computer optimized camera lens optical designs from Japan.

Perhaps they were using Code V which was an early lens design program or perhaps they had some Japanese equivalent of that running on mainframe computers.

 

[David Murphy]

I agree with Walker. The best 50mm lens I've ever owned, and by a lot, is a Pentax Super-Multi-Coated 50mm f/1.4 in M42 mount. And fortunately, there are M42->everything adapters. I like the M42 lenses enough that I bought (a couple of years ago) a Bessaflex TM from Stephen Gandy. I wanted a new platform with modern TTL metering for my M42 lenses. I also use them on my Pentax *ist DS.

Like Walker, I've never cross-threaded one. However, while trying to mount one while not looking, I've gone round and round and round and so - never quite 'catching' to begin the wind on. And I've come close to dropping a lens once or twice - never actually done it yet, though.

And as a final note - nobody has noted the 'best' mount system - the Canon FD breech-mount.

Best Regards,

Bill Mattocks

The first breech lock SLR that I know of is the Praktina -- simple and effective. Sometimes breech lock lenses on the Praktna are hard to remove -- like opening a pickle jar with the same fear of dropping and breaking it.

 

[Benjamin Marks]

The M42 Asahi Takumar lenses take a back seat to no one in mechanical quality or optical performance. Walker

Very true. I use Pentax SM lenses (love the stop-down lever) on my Canon 5D, as well as Lecia R glass, Nikon SLR glass, and Canon autofocus lenes.

Just my 2 hugely off topic cents.

Ben

 

[Jerevan]

Off-topic but nonetheless: I agree on the Pentax Takumar 50 f1.4 - it's a wonderful lens. It sits on my Pentax Spotmatic which I have had for 5 years now, longest I ever had a camera. It's pretty small and light compared to many other lenses. Maybe the cameras and lenses will rise in price one of these days. They're still dirt cheap bargains, for some reason.

As to cross-threading - never happened yet. One trick I know of is that you kind of thread it "against" the threads until it sticks a little and then you do it the right way. Totally hopeless to describe but easy to understand when you see it. 😀

A few times, I've had problems with the screwmount unwinding, but that's user error more than anything (not screwing it on tight enough).

 

[drmatthes]

I hope this is not insulting... When Leica had invented the L39 or M39 or E39 or LSM or LTM or whatever by 1928, Zeiss Ikon came up with a rather complicated bayonet mount for its Contax in 1932; it made use of an inner bayonet for the 50 mm lenses and an outer bayonet for all other focal lenghts. The outer bayonet required that both camera and lens were set to infinity focus before putting the lens on or taking it off, which made it not so much faster than the screw mount. You could even risk your rear lens, shutter and rangefinder mechanism by doing it the wrong way (well, for simple reasons of good luck I didn't manage to do this so far).

I suppose that similar things might have been a common technical problem with early bayonet mounts. Complicated, not so easy to build, more expensive, less reliable or sturdy.

There are rumours that Zeiss Ikon constructed a pentaprism SLR based on the Contax design some time after 1939 as a prototype, and that this prototype was the first 42 mm thread mount camera, being lost during WWII, only to be re-constructed in East Germany as the Pentaprism Contax, also with M42 mount.

Has anyone among us bunch of insulting people got experience with the EXA/EXAKTA bayonet? Never seen one, is it reliable, sturdy, easy to use? Mind you, that in early SLR bayonets you neither needed a rangefinder coupling (as focussing was done on the mirror viewfinder, whatever its design might have been) nor an aperture coupling (well, things just got dark if you stopped down).

To cut it short, the whole thread mount story came upon us as the first and simplest blessing to entitle us of using interchangeable lenses, then came bayonets, or

... the better is the enemy of the good.

Jesko

 

[doubs43]

I hope this is not insulting... When Leica had invented the L39 or M39 or E39 or LSM or LTM or whatever by 1928, Zeiss Ikon came up with a rather complicated bayonet mount for its Contax in 1932; it made use of an inner bayonet for the 50 mm lenses and an outer bayonet for all other focal lenghts. The outer bayonet required that both camera and lens were set to infinity focus before putting the lens on or taking it off, which made it not so much faster than the screw mount. You could even risk your rear lens, shutter and rangefinder mechanism by doing it the wrong way (well, for simple reasons of good luck I didn't manage to do this so far).

I suppose that similar things might have been a common technical problem with early bayonet mounts. Complicated, not so easy to build, more expensive, less reliable or sturdy.

There are rumours that Zeiss Ikon constructed a pentaprism SLR based on the Contax design some time after 1939 as a prototype, and that this prototype was the first 42 mm thread mount camera, being lost during WWII, only to be re-constructed in East Germany as the Pentaprism Contax, also with M42 mount.

Has anyone among us bunch of insulting people got experience with the EXA/EXAKTA bayonet? Never seen one, is it reliable, sturdy, easy to use? Mind you, that in early SLR bayonets you neither needed a rangefinder coupling (as focussing was done on the mirror viewfinder, whatever its design might have been) nor an aperture coupling (well, things just got dark if you stopped down).

To cut it short, the whole thread mount story came upon us as the first and simplest blessing to entitle us of using interchangeable lenses, then came bayonets, or ... the better is the enemy of the good. Jesko

I find nothing insulting anywhere in your post. In fact, it's well stated.

As I understand it, Zeiss was hampered by patents held by Leitz so the Contax was far more complicated than it would have been had Zeiss not been required to work around Leitz-owned ideas. It's a testament to the talented engineers at Zeiss that they produced a fine camera in spite of the obstacles placed in their path.

My first SLR was an Exakta VX-IIa (or Varex IIa as it was known in Europe) and many consider it to be the apex of Exakta quality. I agree and my Exakta VX-IIa is as smooth as any camera you're likely to pick up. The film advance is like silk on glass. The bayonet mount is quick and secure. The camera is a collection of odd features when compared to newer SLRs but it works and works very well. The so-called automatic Exakta lenses for the early cameras through the VX-1000 used an external plunger to activate the aperture blades of the lens and, with a little further pressure, to release the shutter. The last German-made Exakta, the RTL-1000, finally used internal activation of the lens blades but also retained the capability to use the older lenses. There were some fine optics made for the Exakta and the pictures taken with them are as nice as any other.

Walker

 

[RJBender]

I hope this is not insulting... When Leica had invented the L39 or M39 or E39 or LSM or LTM or whatever by 1928, Zeiss Ikon came up with a rather complicated bayonet mount for its Contax in 1932; it made use of an inner bayonet for the 50 mm lenses and an outer bayonet for all other focal lenghts. The outer bayonet required that both camera and lens were set to infinity focus before putting the lens on or taking it off, which made it not so much faster than the screw mount. You could even risk your rear lens, shutter and rangefinder mechanism by doing it the wrong way (well, for simple reasons of good luck I didn't manage to do this so far).

I suppose that similar things might have been a common technical problem with early bayonet mounts. Complicated, not so easy to build, more expensive, less reliable or sturdy.

There are rumours that Zeiss Ikon constructed a pentaprism SLR based on the Contax design some time after 1939 as a prototype, and that this prototype was the first 42 mm thread mount camera, being lost during WWII, only to be re-constructed in East Germany as the Pentaprism Contax, also with M42 mount.

Has anyone among us bunch of insulting people got experience with the EXA/EXAKTA bayonet? Never seen one, is it reliable, sturdy, easy to use? Mind you, that in early SLR bayonets you neither needed a rangefinder coupling (as focussing was done on the mirror viewfinder, whatever its design might have been) nor an aperture coupling (well, things just got dark if you stopped down).

To cut it short, the whole thread mount story came upon us as the first and simplest blessing to entitle us of using interchangeable lenses, then came bayonets, or

... the better is the enemy of the good.

Jesko

Jesko,

I bought two Exakta VXs and an Exa last November. The lenses were loose fitting in the bayonet... too much slop. To make the fit secure, I spread open the kerfs inside the bayonet mount. The procedure is similar to what you do with the Contax RF except that with the Contax the kerfs are on the lens.

You don't have to look at the dots to mount an Exakta lens.

Exakta and Praktina cameras are great SLR cameras to collect, IMO.

R.J.

 

[comp_wiz101]

I agree that screw mounts carried such high popularity among manufacturers for many reasons, including simplicity of machining, reliability, and low cost.
I don't mind using my M42 lenses on my K mount SLR, including a nice little 500mm mirror lens & 135mm Super Takumar, nor do I mind swapping lenses on my Zorki rangefinders.
Conclusion: Good optics + low price + high adaptability = 🙂

 

[XAos]

Dangit you people went and made me buy a lens. I got curious and went to KEH. They had that little Zenitar fisheye without playing Ukrainian Roulette and waiting forever.

Anyone have any input on the Jupiter 21? It looks interesting.

 

[doubs43]

Jesko,

I bought two Exakta VXs and an Exa last November. The lenses were loose fitting in the bayonet... too much slop. To make the fit secure, I spread open the kerfs inside the bayonet mount. Exakta and Praktina cameras are great SLR cameras to collect, IMO. R.J.

RJ, I've tightened a couple of mounts using the same technique. It doesn't require much to make the mount like-new tight again and it's easy to go too far. Be careful and you won't have a problem. The Exakta mount is made from chromed brass I'm pretty certain so it bends easily but has the necessary strength to do it's job.

The Exakta is a great camera to collect and there's a repair book by one Miles Upton that was written for the VX-IIa but often applies to earlier models. I bought one and completely rebuilt my VX-IIa, including new shutter curtains. If I can do it, anyone can!

Walker

 

[comp_wiz101]

Dangit you people went and made me buy a lens. I got curious and went to KEH. They had that little Zenitar fisheye without playing Ukrainian Roulette and waiting forever.

Anyone have any input on the Jupiter 21? It looks interesting.

Hehe... we are GAS inducing.

 

[ZorkiKat]

I'm using a 85mm Jupiter 9 (M42); 58mm Helios 44 (M42); 35mm Distagon (Rollei QBM); 50mm f/1.4 Planar (Rollei QBM) and all my Nikon MF lenses on a Canon EOS A2 with adapters from China. I want to see if I like the results before I buy a Canon D20 or D30.

R.J.

I shoot with M42 lenses adapted on my Canon 300D and 350D. The only EOS mount lens I own is the 18-55 kit lens which came with these cameras- and it's not even a full-fledged EOS since it won't mount on most EOS Canon cameras.

I often shoot with M42 lenses like the Jupiter-9, Helios-44-2, Takumars and Pentacon lenses. My recent favourite is the Oreston 1,8/50 which came off a Prakitca Nova 1. Despite the extra actions like manual focusing and manual aperture stopping down (as well as difficulty in focusing on a screen which wasn't designed for focusing), shooting with M42 lenses are really worth it- in terms of the unique qualities which only these older lenses are able to do.

Got a few examples here:
http://pusangputi.multiply.com/photos/album/7
http://pusangputi.multiply.com/photos/album/1
http://pusangputi.multiply.com/photos/album/6

Jay