Jupiter 8 not reaching infinity R-D1

[Adam-T]

I have a problem with two Jupiter 8 lebses not reaching infinity on the R-D1 - Lens-1 is a 1973 black model which I first noticed it with, you can see that it`s not getting there in the rangefinder too (it focusses bang on) .. Lens-2 is a 1963 Silver model which is sharper wideopen and the infinity issue is even worse. as far as I can tell by the rangefinder patch, they`re fine on the `63 Zorki 4 the silver one came with ..

Has anyone else experienced this?, I stripped the silver one down and cleaned it out but it`s still the same.... thanks

 

[furcafe]

I don't have any LTM Jupiters, but I've had the issue come up w/various LTM lenses on many of my M bodies, not just the R-D1, but I don't worry about it too much as I rarely shoot @ infinity & when I do, it's w/a pretty small aperture so any focus error is covered by DoF. I'm much more concerned w/focus accuracy wide-open @ distances 5m & closer, especially closer than 3 m.

 

[Ash]

Far as I'm aware, this is a common issue with using lenses and adapters. I was warned of this with some of the first lenses I ever bought for SLR. Basically because you're not using the lens as it was originally intended, you can expect there to be errors with focusing at infinity.

You can re-collimate the lens to work on your RD-1 only, I think??

 

[Adam-T]

Good point Furcafe 🙂 .. the infinity mark lines up on the lenses OK but it`s not infinity, both the rangefinder and the photos confirm this.. as you say, it`s closer range which needs F2 anyway and it seems to be bang on focus wise which is weird.

 

[tmessenger]

If the flange on your adapter is the correct thickness (1mm) then screw mount lenses should focus correctly if the lens itself is properly calibrated. Do a search for Brian Sweeney he knows about shimming Jupiter lenses for correct registration on M mount cameras.

Regards,

Tim

 

[pfogle]

I've heard that the 50mm lenses from the FSU (ie all Russian ones) are a bit longer in focal length that the western ones. Since the focus cam on all Leica mount lenses mimics the 50mm cam (to give the correct throw to the rangefinder), this will throw out the infinity on all lenses whatever the focal length.

On my Jupiter-8 I put a thin shim (of paper) on the back of the focus cam in the lens. It's a compromise, but works quite well.

At f2.8 and smaller, it's not worth worrying about, as far as I can see.

 

[furcafe]

True, IME, although it's potentially more of a problem w/RFs as you have no direct visual confirmation of the degree of inaccuracy. I've had this come up w/various combinations of LTM lenses from different manufacturers & LTM-to-M adapters, from both Leitz & modern makers (Cosina or generic), on different M bodies. Not only is the thickness of the adapter an issue, but there's also the quality/accuracy of the threading, as both can lead to the lens being slightly farther or closer to the focal plane. Ideally, as you point out, every lens must be matched w/every body.

Probably due to its high-magnification VF, my M3 is the most finicky, as there are lenses that will focus fine @ infinity on my LTM bodies & the other M bodies, but won't get to infinity (as viewed in the RF patch) on the M3, but every lens that works fine on the M3 also works fine on every other M or LTM body. The R-D1 is more of a wild card & I think the not-quite-infinity issue on it has more to do w/the lower precision/base length of the Bessa RF mechanism, as has been discussed many, many times here & on other fora.

Far as I'm aware, this is a common issue with using lenses and adapters. I was warned of this with some of the first lenses I ever bought for SLR. Basically because you're not using the lens as it was originally intended, you can expect there to be errors with focusing at infinity.

 

[Adam-T]

Thanks folks.. The adapter is a Voigtlander so is of good quality, also the focus seems fine, the focal point agrees with the RF patch even when the J8s are focussed as far as they`ll go (it`s as if you need to turn the focus more but there isn`t any more) ..

I`d have thought that re-collimation would be to make the actual focus area agree with the range finder so that the camera actually focusses on what the rangefinder says it`s focussed on (this is fine on both lenses) - it`s more like that the focussing range has been reduced maxxing out at below infinity. Strange..

the CV lenses are fine but they`re modern and designed to work with adapters

 

[Peter Klein]

I agree with pfogle on this one. It mirrors my experience with Russian lenses. Either they are correct close up and off at infinity, or correct at infinity but off close up. It is possible to adjust them so that they are almost right at the ends and perfect in the middle, which depth of field may cover if you don't shoot wide open.

My Jupiter-8 focuses perfectly on the Zorki 4 it came with, but not on my Leica bodies. I've had the same experience with two Jupiter-9 (85/2) and an Industar 61 L/D. They are all good at about 12 feet to infinity, but quite noticeably off closer than that.

There are people who say that their Jupiters focus perfectly at all distances on Leicas and Bessas. If so, more power to 'em, but that's not what I've experienced.

Moral: Wanna play Russian roulette? Like tinkering? Great, you can do it very cheaply with Russian lenses. If not, get old Nikkors and Canons, CVs or Leica lenses. Check Dantestella.com for some in-depth info on all this.

This is not to disparage the optical quality of the lenses. QC was very uneven, but good lenses are wonderful, on a camera that focuses them properly.

--Peter

 

[Adam-T]

I think that if they`ve got to be off then mine are the way I want them, i`m more likely to use F2 at close range than infinity and the silver 1963 one is very sharp even wide open (the black one is dreamy for some reason below F2.8 , the optics are as clear as a bell)

 

[tmessenger]

Here's a link on collimating a RF lens for infinity: http://elekm.net/zeiss-ikon/repair/collimate/ From what I've read the J8 can have problems and may need to be collimated. I have a J8 coming that was collimated by Brian Sweeney for M mount and will let you know how it focuses on both ends when I get it.

Regards,

Tim

 

[Adam-T]

Thanks, I`ll take a look at that link 🙂

 

[tmessenger]

OK if you really want to know here is a link to an article by Brain Sweeney with photos explaining the problem and how to fix it, just down load the "Servicing Junpiter 3" pdf.

http://www.pentax-manuals.com/repairs.htm

Good luck

Tim

 

[Adam-T]

Thanks, I didn`t think of looking at the other service guides, I just looked at the J8 one which only tells you how to take the lens apart for cleaning ..