Modifying RF Lenses for Closer Focus?

[Phil_F_NM]

Yeah, I am pining over a 50/1.9 Hexanon, and I'd never touch one for this kind of modification.

The method bluesun mentioned to effectively give more close focus would work just as well but because the coarse thread of the LTM mount, it would allow for a lot of play. This could be cured by using a brass (or ABS) ring as a shim to stand the lens off the mount. I'm measuring this now against my 5cm f/2 Super Rokkor mounted on my M4. A shim 1.5mm thick gets focus down to about 27 inches. Unscrewing the lens any further will not allow enough purchase of the threads in the mount and creates the possibility of stripping the threads and/or dropping the lens.

Phil Forrest

 

[Rob-F]

I usually use an SLR when I need close focusing. However, I carry a +3 diopter supplemental close-up lens to mount on my rangefinder lens should the need for closer focusing arise.

The +3 diopter lens will enable a closer focusing distance all right, but the rangefinder will still be in coincidence at the lens's native focusing distance. How do you accomplish satisfactory focusing and framing?

 

[David Hughes]

Just curious. Why do lens makers limit the minimal focus distance? Not really sure why thye limit to 1m instead of 50cm for example. Any idea?

Well, they had to stop somewhere and 1 metre is a nice 'round' figure, then there's the accuracy of the RF when used on things below them rather than in front of them, and the framing.

And you could alter the lens and discover the hard way that the RF in the camera stops at 1 metre to match the lenses...

SLR's are the answer for close ups, as others have said.


Regards, David

 

[571514m3]

This may be kind of an odd question. Is anyone aware of whether it is possible to modify a RF lens that has a native minimum focusing of 1.00m to go down and RF-couple down to 0.7m? Like taking a Canon 50mm f/1.4 and shortening its minimum focusing? If so, are there any known shops that can do this? I am aware that such products exist for digital systems with liveview, but this would be for film. Thanks!

Why would you want to go to all that trouble? This is something that was solved by photographers decades ago and it is super simple. I am not sure what focal length lens you are using but you can definitely find a 1 Diopter close up lens on line. With a 35mm lens that would mean that you have infinite options. You set your lens to:
6ft then your subject to lens distance is 25.5"
4ft.....21.5"
3ft (typical on leica lenses)...19"

That will give you all the options for close portraits. You could even use 2,3 or 4 diopter close up lenses and get really close. The focus distance charts are easy to find on line and easy to use. Of course that is even easier to use with a SLR or Live View Leica or other digital. But even with a film body it is super simple.

Have a look on the bay for 39mm Close-Up Filter Set +1+2 +4+10 Macro Lens Zoom Lense Close Up 39 MM

 

[Sonnar Brian]

For a lens as rare as the Hexanon- go with the spacer between the lens and the body. I remember RFF members doing this over 10 years ago. You can put the spacer between the lens and an M Adapter as well. You lose infinity focus, and the distance scale in meaningless: but you get a closer focus. Think of it as a dual-range lens.

 

[bluesun267]

Though it may be well-intentioned, suggesting that the OP just use an SLR is beside the point. I'm sure the OP was aware that SLRs exist and offer closer focus than RFs before he asked the question.

Why manufacturers stopped at 1m on earlier RF systems is a valid point of bewilderment. Being completely aware of the limitations in accuracy of rangefinders (and seeing that this 1m rule was gradually loosened over the years) it is a bit frustrating that certain great vintage optics are constrained by such a long close-focus distance. Between 28" and 40" can make or break many shots, especially with 50mm and longer lenses, and not just with portraits.

When you are aware of how rangefinders work and can utilize their strengths and weaknesses to your advantage, having a lens that focuses down to at least .7m is a huge asset and can give you the ability to make many wonderful, perfectly sharp and well-framed close-in shots.

Of course we know the reason for 1m was that manufacturers felt they were balancing the needs of the average user to get a reasonably sharp picture on the first try. But not all felt the same. 1950s-60s Kodak Retinas (with their relatively fast Xenon 50/2 lenses) routinely focus down to 2.5ft and nobody complained so it still remains a question why this arbitrary 1m limit was so firmly entrenched.

 

[bluesun267]

I'd add that it is doubly frustrating that certain lenses in Voigtlander's and Konica's venerated (and now rare and increasingly expensive) LTM line up made in the 90s through the early 2000s continued to adhere to this rule or some variation of it, like .9m 30-odd years after Leica standardized on .7m for nearly all their M-lenses.

If it weren't for this .9m close focus limit, a 35mm f1.7 Ultron or a Konica UC Hexanon 35mm would be much higher on my list of wants.

I don't know if others agree, but I like the recent trend of even closer close focus (.5m) on some of the newer M-mount lenses. This is one instance where the needs of digital provide particular advantages to film users. It doesn't bother me that one loses rangefinder coupling at a certain point. (I've been a LTM Nikkor 50/1.4 shooter for years).

Of course, since I only shoot LTM cameras, it's a moot point to me. But if a certain manufacturer were to do a special run of these new, closer focusing optics in LTM, I'd buy one... or two.

 

[das]

Totally 100% agree that between 0.7m and 0.9m is very often the "sweet spot" with 50mm RF lenses, especially with 35mm RF lenses. Owning both a UC Hex and a S-Mount 35mm f/1.8 W-Nikkor, the 0.9m minimum focusing is a REAL bummer. I ditched my Canon 50mm f/1.4 for the minimum focusing issue. I had my M3 body modified to natively focus to 0.7m as well. I think it's an important capability.

While I would never, ever butcher a lens, with all of the lens converters out there who are fabricating new helicoids/cams to use SLR lenses on Leica Ms with RF coupling, I mean, if someone carefully modifies a 1950s RF lens to focus down to 0.7m, have we done irreparable violence to it? I can see both sides of that sentiment.

Though it may be well-intentioned, suggesting that the OP just use an SLR is beside the point. I'm sure the OP was aware that SLRs exist and offer closer focus than RFs before he asked the question.

Why manufacturers stopped at 1m on earlier RF systems is a valid point of bewilderment. Being completely aware of the limitations in accuracy of rangefinders (and seeing that this 1m rule was gradually loosened over the years) it is a bit frustrating that certain great vintage optics are constrained by such a long close-focus distance.

Between 28" and 40" can make or break many shots, especially with 50mm and longer lenses, and not just with portraits.

When you are aware of how rangefinders work and can utilize their strengths and weaknesses to your advantage, having a lens that focuses down to at least .7m is a huge asset and can give you the ability to make many wonderful, perfectly sharp and well-framed close-in shots.

Of course we know the reason for 1m was that manufacturers felt they were balancing the needs of the average user to get a reasonably sharp picture on the first try. But not all felt the same. 1950s-60s Kodak Retinas (with their relatively fast Xenon 50/2 lenses) routinely focus down to 2.5ft and nobody complained so it still remains a question why this arbitrary 1m limit was so firmly entrenched.

 

[David Hughes]

FWIW, some years ago I needed something optical modified to work just outside its normal range; I had to get the calculations done by an expert and the physical modifications done by a craftsman. As a result my advice is that I would not start from here if I was you; that's a line from a very old but telling joke.

I mentioned SLRs as they are very cheap as are the extension tubes and suitable lenses.

For that matter I don't like getting too close with 50mm lenses and wider as the distortion is annoying and so is the clutter in the background. Better to use something like a 100 or 135mm lens and pick out the detail but that's just my opinion...


Regards, David

 

[analoged]

Would love to have my 35 pre ash lux focus down to 0.7m

 

[jmanivelle]

Would love to have my 35 pre ash lux focus down to 0.7m

I actually have one...

A 35 Summilux v2 from 1970 originally built in Eclair Cameflex CA-1 mount with a 0,60m minimum focussing distance.
Had it adapted to M mount with RF coupling.

Here a couple of shots taken on the M10 at about 0,70m:


Untitled by JM__, on Flickr



Untitled by JM__, on Flickr



au Musée Rodin by JM__, on Flickr

Best, JM.

 

[splitimageview]

1m is pretty limiting for me. 0.7m of course is better but even run-of-the-mill SLR focus of 0.5m isn't ideal for what I shoot...close focus is one of the major factors I look at when buying lenses. Not necessarily macro, just close...

 

[Goody]

Not totally on topic but Canon made a close up lens with a corrective lens for the RF/viewfinder (as a unit) called the "Auto Up". I have one and it seems to work decently on my Canon P. Doesn't remotely line up correctly on the Canon 7, perhaps they made a different model for the 7.

 

[phojsu]

My CV 28mm f/1.9 remains my favorite 28mm for the M-9, even after getting a ZM 28mm Biogon. In that the CV 28/1.9 is a LTM lens, it must be used with a LTM to M adaptor ring. This allows me to unscrew the lens a half-turn, full-turn or even a turn and a half in situations where I can shoot a frame and review focus on the M-9's monitor screen.

I've learned to guesstimate focus down to about a foot with this method. I just shoot until I get it in focus and discard the O-O-F shots after the fact.

I have a very large washer that fits in-between my Canon LTM 50mm f/1.2 and 50mm LTM to M ring adapter. It increases the close focussing to ~ 0.6 m, the near limit of my Leica M's RF focussing. This at the expense of infinity focus which is easily regained by removing the washer. This required a bit of experimentation to find a useful washer but it works for me. It is functionally a minimal extension tube.

 

[lukx]

Professional repair shops like Skyllaney can perform such modifications with good results.

The old 5cm LTM Nikkors are perfect for this because they naturally have an extended focus range. All you need to do is take the lens apart and file down the mounting threads so the rangefinder arm of the camera can follow further into the lens. You need the right tools and some confidence but it can be done. I have performed this operation on both the f2 and f1.4 versions of the lens.

It’s also possible to modify the Canon LTM 50mm 1.5. I got mine down to 0.8m which is the furthest I‘d go (beyond that the structural integrity of the rangefinder cam might be in danger). But it’s a more complicated operation and requires precise filing of the required parts.

To me such projects are a lot of fun.

 

[phojsu]

Yeah, I am pining over a 50/1.9 Hexanon, and I'd never touch one for this kind of modification.

The method bluesun mentioned to effectively give more close focus would work just as well but because the coarse thread of the LTM mount, it would allow for a lot of play. This could be cured by using a brass (or ABS) ring as a shim to stand the lens off the mount. I'm measuring this now against my 5cm f/2 Super Rokkor mounted on my M4. A shim 1.5mm thick gets focus down to about 27 inches. Unscrewing the lens any further will not allow enough purchase of the threads in the mount and creates the possibility of stripping the threads and/or dropping the lens.

Phil Forrest

I have a pair of LTM lenses I frequently use on my M9 Leicas, a Canon 50mm f/1.2 and a CV 28mm f/1.9. In the waist bag I use to carry spare batts for the power hungry Leicas, I have a thick washer that I use as an extension ring, mainly with the 50/1.2.

I realize I lose infinity focus but for staying just at the .65 m near limit of the M9 rangefinder, and out another couple of meters, it is a quick & dirty solution / work around.

Actually, I regularly use my 28/1.9 unscrewed either a half turn or a full turn to achieve a closer focus when sitting across a cafe table from my wife. The rectangular hood on my 28/1.9 helps me determine how much the lens is unscrewed.

Note, I do this sitting at a cafe table and not walking around.

The hood on my CV 28/1.9 is one intended for a current Leitz 35/1.4 which is a friction fit with a tightening collar to keep it in place, works like it was made for this CV 28, thank you Leica.

 

[peterm1]

A bit of an aside for anyone planning to use Leica rangefinder glass on a mirrorless camera. You can buy a Leica M adapter with a built-in close focus helicoid. Bear in mind all such adapters are quite expensive (comparative with ordinary adapters) and some will not focus to infinity with the helicoid adapter mounted, though of course these do focus more closely. I have not checked which mirrorless systems these are made for other than L mount but I believe that other system mounts are accommodated by some adapter makers. I recently bought a Light Lens Lab adapter with helicoid, for Leica M to L mount and can say it is an excellent piece of kit with very high build quality, and it does focus to infinity when it is mounted. For close focus you simply focus to the nearest point of focus on the mounted lens then switch over to the focus dial on the adapter and continue focusing closer. If using a lens in LTM mount simply add an LTM to M adapter to the adapter stack. Similarly, for example you can add a suitable lens to Leica M adapter (e.g. if using a Nikon AI lens - an Ai to M adapter) and this allows your SLR lens to become close focus when using the helicoid adapter.

Not perhaps what you need, Das, but some here may benefit from this knowledge.

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The Light Lens Lab M-L Mount Adapter with Close Focus Helicoid enables you to mount any Leica M lens on the Leica CL, TL & SL series cameras.

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