Does screw mt. to M adaptor affect focus?

[naren]

I wonder if infinity focus is affected by these adaptors. Maybe since the cameras are mostly used for wide-angle the effect is negligible? It seems to me any adaptor would create at least a modest amount of lens extension leading to a problem with infinity focus.

I recently purchased an M42 screw mount adaptor on eBay to shoot a nice 200mm f/4 Takumar lens on my Nikons. The posting said "infinity focus" but with that lens on my D200 I wasn't getting even close to infinity focus. Images from that lens I did of closer subjects look real nice but I'm pretty disappointed about this. And if there's even a small effect, like you will have infinity focus when using the M mount adaptor if you stop down to f/5.6 that would affect my shopping list.

 

[squirrel$$$bandit]

If you mean Leica screwmount to Leica M, there is no focus problem whatsoever.

 

[Pickett Wilson]

There is a huge spread of quality control on the cheap adapters available on eBay. Some work fine, some are awful. Kind of a roll of the dice.

 

[Dave Wilkinson]

When Leica introduced the M mount camera, the film-to-flange distance was reduced by one millimeter compared to the screw mount models-to allow the use of screw lenses via an adaptor. If your adaptor has a flange of EXACTLY 1mm thickness, there will be no problem across focus range.
Dave.

 

[payasam]

I have used 28mm to 135mm screw mount lenses with M adapters and haven't had any focus troubles. It pays to pay a little more for accurately made adapters.

 

[ferider]

Leica, CV and Marumi adapters are usually OK.

Others vary in thickness and built quality.

The thickness variation creates more problems for wide angles.

Cheers,

Roland.

 

[tedwhite]

You've taken an M42 Pentax Takumar lens and fitted it to a Nikon camera? Anybody's guess on that one, especially with an unknown brand adapter. I didn't know Pentax and Nikon would ever meet. My advice is to buy a Pentax Spotmatic camera body for about $25, then your very good lens will screw right on and you'll definitely have infinity focus!

 

[tennis-joe]

I purchased two LTM to M adapters from Cambridge Photo and they described them as Japanese, me thinking they would be better than Hong Kong adapters. Well they weren't threaded correctly and the f markings didn't hit the top. I won a Leica made adapter on Ebay for 35 mm lenses and it fit beautifully. I sent back the Cambridge adapters, still hoping to get a refund, and ordered from CV - Steve Gandy and those worked great. Have to watch out for the sharp edges when taking them off but the photos are not affected.
Joe

 

[ferider]

Reg. the adaptation of M42 lenses to Nikon bodies, M42 registration distance is 45.5mm, while Nikon is 46.5mm. So, maintaining infinity focus is only possible if either (a) the adapter has an optical element or (b) you shave off some of the M42 lens' rear (which I did once for the Helios 40-2).

Cheers,

Roland.

 

[Sam N]

Most of my adapters are Voigtlander, one is no-name. All of them work 100%.

 

[Al Kaplan]

There are also used adapters kicking around from the 1950's and 60's when people were first making the switch from LTM to M bayonet. One company, Spiratone, sold a set of three for $10, or $5 each (plus 35 cents shipping of course!). If you're lucky you might find used ones kicking around an older photo store for a couple of bucks apiece, even genuine Leitz adapters.

 

[peterm1]

They should not do so. Interestingly though, I had a Leica branded one for the standard 50mm lens that was slightly thicker than another Leica branded one I had for the same lens. The former also had a slightly shinier chrome coating. This thicker one was noticeably harder to get onto and off of the lens mount which is the thing that alerted me, but once noticed in this way I confirmed it with a micrometer. The actual variation was slight and it did not seem to create a problem with focusing. Another odd thing about using these and SOME lenses is that a long lens -the example I have experienced is the Hektor 135mm f4.5 - but I think it applies also to the Elmar - do not line up as expected. These long lenses have their own tripod mount. On a LTM camera of course the tripod mount is located directly underneath. But when used on an M with adapter it screws past that point. However it still focuses properly - just looks odd.

 

[naren]

You've taken an M42 Pentax Takumar lens and fitted it to a Nikon camera? Anybody's guess on that one, especially with an unknown brand adapter. I didn't know Pentax and Nikon would ever meet. My advice is to buy a Pentax Spotmatic camera body for about $25, then your very good lens will screw right on and you'll definitely have infinity focus!

On the D200 with the crop factor of the chip, the 200mm Takumar is my longest lens. Not much longer than my 180mm f/2.8 Nikkor but a little. And when I'm shooting film, a Spotmatic won't replace my F3's by a long shot. It is a pretty looking old camera though, and I wouldn't mind a nice lookin' body for the bookshelf. I would exercise it now then of course to honor it's place in history.😉

 

[naren]

Reg. the adaptation of M42 lenses to Nikon bodies, M42 registration distance is 45.5mm, while Nikon is 46.5mm. So, maintaining infinity focus is only possible if either (a) the adapter has an optical element or (b) you shave off some of the M42 lens' rear (which I did once for the Helios 40-2).

Thanks Roland and everyone else for the good info. I wonder if the shaving of the lens rear is a project I should undertake myself. Not sure how I would go about it. What's your method?

 

[naren]

The CV adaptors are pretty pricey then though, eh? I mean if you can find a old one like the SM to M lens adaptors recommended here on the used market. They should work fine with the CV screw mount lenses, say on an R3A?

 

[laptoprob]

Adapting an adapter

Adapting an adapter

I have a Leitz adapter that got dented. And protected the lens it was on.😱
Now, having mostly undented the adapter, I will sand it down to make the Kobalux 21mm focus properly on my R-D1. The chrome bit is quite hard wearing ofcourse, but a little patience does miracles. Take good care to keep everything level. Place the sanding paper on a strong and really flat surface, like a flat (polished) stone slab.

 

[ARI_1969]

hi
It#s not essential to use polished stone slap. a pice of thick glas (window glas) will do fine as well. Make sure to put it on flat ground. Your kitch table might be good enough.

greez