M42 to M39 Adapters

[ncc1701]

It seems that a lens I got on ebay was had an incorrect item description.
My fault anyway, didnt do any research on the lens.

Anyway its a pentax screw mount

HANIMAR TELEPHOTO LENS F 135 1:3.5 SCREW MOUNT


Are adapters available and does it throw your focus out of whak?

 

[dominicLF]

M42 to M39

M42 to M39

They make such adapters. But, you would only be able to scale focus.

No, No, The Pentax M42 mount is for an SLR and obviously has a much longer focal length than any RF. I have one of these adaptors and use it for various experimental lens combinations and homemade lenses, but you cannot scale focus with the existing scale on the lens. Any reducing adaptor is going INCREASE the focal length. For this lens, I wouldn't bother. On the other hand, you can buy yourself a nice Pentax Spotmatic or (and I like these much better) one of the Pre-Spotmatic models for under $50. In fact, I'll sell you one of my SVs if you want.

 

[Harvey Platter]

No, No, The Pentax M42 mount is for an SLR and obviously has a much longer focal length than any RF. I have one of these adaptors and use it for various experimental lens combinations and homemade lenses, but you cannot scale focus with the existing scale on the lens. Any reducing adaptor is going INCREASE the focal length. For this lens, I wouldn't bother. On the other hand, you can buy yourself a nice Pentax Spotmatic or (and I like these much better) one of the Pre-Spotmatic models for under $50. In fact, I'll sell you one of my SVs if you want.

I think you'll find you're quite wrong on that.

Most adaptors for SLR mounts to Leica screw take account of the large difference in back focus between SLR designs and rangefinder cameras so that the SLR lens is placed at the right distance from the focal plane to focus correctly at infinity. Thus scale focussing is correct when the lens is so mounted.

I proved this is so to my own satisfaction when using a cheap Japanese adaptor to mate a 50mm Takumar to a Canon P.

 

[dominicLF]

I think you'll find you're quite wrong on that.

Most adaptors for SLR mounts to Leica screw take account of the large difference in back focus between SLR designs and rangefinder cameras so that the SLR lens is placed at the right distance from the focal plane to focus correctly at infinity. Thus scale focussing is correct when the lens is so mounted.

I proved this is so to my own satisfaction when using a cheap Japanese adaptor to mate a 50mm Takumar to a Canon P.

Harvey, Do mean that the adaptor has an alternate scale built into it? I have seen pictures of these adaptors and I'm sure they would work. Where did you get yours? If the adaptor does not have its own helical and scale (as most don't), there is now way that it could work because the adaptor is effectively a macro tube extension.

 

[Kin Lau]

There's a m42 to LTM (I'm still waiting for mine... I think they strapped it to the back of a sea turtle for delivery) but I don't think there's m42 to m39. Some of the older Russian SLR's use m39, same register distance as m42.. Dan Igger's (username "iggers") has an SLR like that, probably a few others here do as well.

In either case, m42 to LTM is only good for wide angles and scale focusing, just like the CV 12, 15 & 25.

 

[dominicLF]

I think you'll find you're quite wrong on that.

Most adaptors for SLR mounts to Leica screw take account of the large difference in back focus between SLR designs and rangefinder cameras so that the SLR lens is placed at the right distance from the focal plane to focus correctly at infinity. Thus scale focussing is correct when the lens is so mounted.

I proved this is so to my own satisfaction when using a cheap Japanese adaptor to mate a 50mm Takumar to a Canon P.

Wait, you're saying that you put a reducing adaptor on a lens and it still focused to infinity. I'm sorry, but that seems optically impossible.

 

[dominicLF]

I do it all the time. 🙂
The adapter is the right thickness to allow the SLR lens to come to focus at the RF's film plane.

If you have a digicam, would you mind snaping a pic of this rig? For some reason I can't wrap my mind around it.

 

[Kin Lau]

Wait, you're saying that you put a reducing adaptor on a lens and it still focused to infinity. I'm sorry, but that seems optically impossible.

m42 to LTM will focus to infinity. LTM to any SLR mount will not, macro only.

 

[bmattock]

http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

M42 Pentax screw M42x1 thread 45.46mm
M39 Zenith 3M M39x1 thread 45.46mm
LTM Leica screw M39x26 thread 28.80mm

Thus, if an adapter reduced M42 to LTM and was exactly (45.46-28.8)mm long, it would have the correct back focus distance. Without a rangefinder tab, of course, greyhoundman is correct - scale focus only. Wide angle lenses would tend to be more accurate by virtue of extended depth-of-field effects.

I have not seen an M42 to LTM adapter, but I have seen (and nearly purchased) a T2 to LTM adapter, which is nearly the same thing. T2 having a 55mm focal registration distance (which allowed it to be adapted to all types of 35mm camera mounts, as intended).

Best Regards,

Bill Mattocks

 

[dominicLF]

m42 to LTM will focus to infinity. LTM to any SLR mount will not, macro only.

You know what, you're absoutely right. I don't know what I was thinking. I havn't had my coffee yet....

 

[dominicLF]

Here is one that has been for sale for quite awhile.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=30059&item=7528050290&rd=1&ssPageName=WDVW

I have this adaptor and this seller is very reliable, but the shipping takes a very long time. I ordered this one and when it arrived it was not steel, but black anodized aluminum, which is probably better.

 

[dominicLF]

Still-- if I may speak now that I've had my coffee--attempting to scale focus a 135mm lens is not very practical. The best thing would be to buy an old Pentax camera to go with it. They are excellent and totally indestructable old cameras.

 

[Kin Lau]

I have this adaptor and this seller is very reliable, but the shipping takes a very long time. I ordered this one and when it arrived it was not steel, but black anodized aluminum, which is probably better.

That's who I bought mine from as well. The sea turtle carry my adapter is probably somewhere in the Pacific right now, then it'll hand off to a land turtle :bang:

 

[Harvey Platter]

You know what, you're absoutely right. I don't know what I was thinking. I havn't had my coffee yet....

It comes to all of us. It's called senility.

Now then, where did I put my flibberty-gibbet?

🙂

 

[kiev4a]

I've used an M42 28mm Soligor on my LTM cameras with excellent results. The thickness of the adapter does not change the focal length of the lens. It was designed for an SLR with a much deeper lens-to-film distance. The adapter puts it at the correct distance from the film plane of an LTM camera. I don't thing I would try using it wath anything but a wide angle lens, however. My mount came from the seller in Macau. Only took about two weeks to the USA.

 

[zuikologist]

Thank you for this - I didn't know this accessory existed. This now opens a whole other world of wideangle lenses for the Zorki and Bessa at low cost. Of course, it eliminates most of the upsides of rangefinders (compact, light lenses, easier focusing etc)

 

[Doug]

As mentioned, due to the non-RF-coupled scale focusing, it's most practical for wide lenses... which coincidentally turn out to be larger/bulkier than those made for the RF camera! You really have to be dedicated (read "cheap") to go this route! 🙂

I have a similar adaptor to use M42 Pentax lenses on my Olympus Pen F. It doesn't maintain diaphragm automation, but at least I can focus on the screen without resorting to scale focusing... so it's practical for long lenses.

The Pen F's film plane to lens flange distance 28.95mm so it might be possible to adapt L39 lenses to fit and focus to infinity... but the swinging mirror doesn't allow much back-focus!

 

[satbunny]

HANIMAR TELEPHOTO LENS F 135 1:3.5 SCREW MOUNT

It would be less painful to get an old M42 body, there were many made from the very lovely Pentax SVs to clunky East German Prakticas. Should be very cheap, maybe more than the adaptor. Plus that gonna be a heavy lens, it may pull the whole camera setup down so much at the front that it just tires you out.

 

[Elmer Fishpaw]

I have a Yashica FX-D held together with electrical tape....I use a Y/C to M42 to M39 adapter to use a Mir 37 M39 mount lens. Works fine and dandy!!

 

[Scarpia]

Here is one that has been for sale for quite awhile.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=30059&item=7528050290&rd=1&ssPageName=WDVW

The one that has been on sale was bought by me (carlogerard [another operatic character]). Unfortunately, due to faulty machining it focuses well beyond infinity. I e-mailed the seller not requesting a refund, but just to inform him and after four days have still not received a reply. I constructed a shim by twisting solder wire around the upper part of the 39mm end and this has corrected the problem. The confusion in this thread seems to be that people cannot envision the difference
between a RF lens and a SLR lens which has a much longer flange to film distance. The adapter I received is actually too short by a milimeter or so. I also have a T1 to 39mm RF adapter which functions perfectly.
Kurt M.