range finder accuracy and russian lens

[franceluxemburg]

I have now 3 lenses for my Konica Hexar RF and Voigtlander Bessa T :
a VC 40mm f/1.4 nocton classic,
an industar 50mm f/3,5 in LTM vith VC adapter LTM => M
a Jupiter 3 50mm f1,5 in LTM

At infinity the 3 lenses are correctly focussed if i trust the marking of the lens.

Test of accuracy of the range finder coupling at 1 meter camera on tripod :
VC 40 mm focussed at 1 meter, the tapemesure says 1 meter also.
Industar 50 f/3,5 same distance focus 1 meter, tapemesure 95cm!
Jupiter 3 same distance focus 1 meter, tapemesure 88cm !!

Now the prints and the scans at full opening : the focus on a book is
correct !
So that great, but at 1 meter a focus error of 12 cm should be out of focus with
a f/1,5 opening? Am i correct?

An explanation please !

 

[doubs43]

I'm unsure how you've done your tests but with the Bessa T, I use the rangefinder to focus and then check accuracy of focus on groundglass with a 10x loupe. I just did this Friday with a 35mm Summaron LTM lens that I had completely taken apart, cleaned and put back together. Focus was dead accurate wide open at 6 feet and infinity.

Walker

 

[Kim Coxon]

Hi,
The Jupiters are notorious for being out and the J3 is the worst culprit. There is a divided as to the cause but most need collimation. Brian Sweeney ran a thread on the J3. Rather than look for that you can get a PDF version from my website here. http://pentax-manuals.com/repairs.htm. As walker says some form of loupe and ground glass screen is best. You will need to re-shim the lens and perhaps mess with the mounting of the rear group depending on whether you need to shorten or increase the focal length.

Kim

 

[iñaki]

Hi,
The Jupiters are notorious for being out and the J3 is the worst culprit. There is a divided as to the cause but most need collimation. Brian Sweeney ran a thread on the J3. Rather than look for that you can get a PDF version from my website here. http://pentax-manuals.com/repairs.htm. As walker says some form of loupe and ground glass screen is best. You will need to re-shim the lens and perhaps mess with the mounting of the rear group depending on whether you need to shorten or increase the focal length.

Kim

You have an interesting website Kim, thanks for sharing the information. I have to try it with my 61 LD and J8

 

[franceluxemburg]

Re-shim the lens

Re-shim the lens

Hi,
The Jupiters are notorious for being out and the J3 is the worst culprit. There is a divided as to the cause but most need collimation. Brian Sweeney ran a thread on the J3. Rather than look for that you can get a PDF version from my website here. http://pentax-manuals.com/repairs.htm. As walker says some form of loupe and ground glass screen is best. You will need to re-shim the lens and perhaps mess with the mounting of the rear group depending on whether you need to shorten or increase the focal length.

Kim

Kim Coxon,
I have do believe that you can do the job but i do not trust my hands for that job.

As i said, what puzzle me is that the pictures looked in focus both on print and scans.
The sharpest lens was the nocton. At f/1,5 i expected the jupiter to be a little soft, that is the case but also to be a little out of focus.

Well, i will probably have to test more so that i know if i can the russians lens indoors wide open...

Best regards

J.B.

 

[Kim Coxon]

Hi,
There have been several comparisons done between the J3 and other lenses including Canon, Nikon and CV lenses. In nearly all cases the J3 has shown up well and can be a very good lens. In these cases both of the trials I posted and those of Brian Sweeney, the lens was correctly adjusted. If someone says their J3 is soft, the most likely reason is that the collimation is out especially wide open.

If yours is giving good results, ignore the distance scale. If it does cause problems, I am onlt across the other side of the Channel and can easily service for you.

Kim

Kim Coxon,
I have do believe that you can do the job but i do not trust my hands for that job.

As i said, what puzzle me is that the pictures looked in focus both on print and scans.
The sharpest lens was the nocton. At f/1,5 i expected the jupiter to be a little soft, that is the case but also to be a little out of focus.

Well, i will probably have to test more so that i know if i can the russians lens indoors wide open...

Best regards

J.B.

 

[wyk_penguin]

If you are using the RF, why bother about the distance scales?

 

[ruben]

I have now 3 lenses for my Konica Hexar RF and Voigtlander Bessa T :
a VC 40mm f/1.4 nocton classic,
an industar 50mm f/3,5 in LTM vith VC adapter LTM => M
a Jupiter 3 50mm f1,5 in LTM

a) Testing a lens wide open at minimum distance, is the hardest and therefore truest test for a lens. Therefore I welcome your test.

b) As said so many times, up to the point that many members here who know it do not want any more to repeat it, FSU lenses quality differs without much rationality. I tested like 5 different J-8s at 1m F/2 and found trash and diamond.

c) But I tested Kiev mount J-8s on a real Kiev camera. And a very interesting question may be if our Soviet friends kept the accuracy of film plane to lens distance constant, along all the years of Kiev production, better than lens quality.

d) Assuming that the answer to c) is positive, the implication is that you should test your Soviet LTM lenses on the cameras they were designed to, first of all, to determine if your Soviet samples are good or bad in the first place.

e) With Soviet cameras and Soviet lenses 1meter in the viewfinder MUST be 1 meter in the distance scale. Otherwise either the range finding camera mechanism is fault, which is the most usual case, or the lens distance to film plane is fault.

f) I cannot finnish my opera without warmly recommend you to totally disregard any advice about rangefinders distance scales. Rangefinders distance scales tell a lot about camera status. This type of mis-advice only discloses the ignorance of the adviser, as happened to me once that a camera fixer without any idea about Soviet cameras told me. Incidentally, he could not fix the ranfinding mechanism...
Regards,
Ruben

PS: in case the answer to point c) is negative, there is no reason to dispair. It is just a queston of matching body and lenses.

 

[dll927]

I'm still shaking my head over the fact that so many FSU camera owners seem to be do-it-yourself-ers. Apparently the relatively low cost of the machines tempts people to figure that if something is out of whack, it can be replaced if there is a screw-up.

But there seems to be a continuing discussion about accuracy of focus on the cameras. This could a matter of the age of the equipment, right? Chances are the Russkis didn't plan on the adjustments possible on older Leicas when a CLA is done. And how many would go to work in the evening on their own M-3??

I've read in photo magazines that any amateur "repairing" a camera is akin to the guy who serves as his own attorney - he has a fool for a client. But it seems to be almost endemic with FSU cameras. Granted, I've seen "Leica repair manuals" on eBay and other sites, but I'm not tempted to play with my M4-2 or with a Zorki.

 

[pshinkaw]

Guilty, Guilty, Guilty!

I'm not afraid of cutting into Soviets, Minolta, Mamiya. Konica, Fuji, Canon, Yashica, Chinon, Cosina, Pentacon, or Kodaks. Except I won't go into Retinas, Exaktas or ZIV. Only a qualified repair person is allowed to touch my M-2 and my Nikons are seemingly indestructible.

You learn from mistakes, and I have some bodies and lenses that are solely for learning.

When you refuse to hire a lawyer and try to do your own self-surgery, it's harder to get a real benefit from learning from mistakes. Sometimes they are permamnent and irreversible.

-Paul

 

[je2a3]

Guilty plea as well!

But to my defense as well as other FSU DIYers, no camera technician in the USA would touch an FSU and even if someone did, it won't be cost effective. Granted I'm sort of a techno geek....

Joseph

 

[franceluxemburg]

Thanks for your comments.
i will try more short range pictures on real subject, so that will be my wife being again the test subject.

All i want is my average portrait picture to be properly focused !

 

[Kim Coxon]

Guilty as well. I am not going to pay $80-$100 to get a lens serviced that is worth $25 when it is done. On the other hand I wouldn't dream of opening a Leica and that is also part of the root of the problem. The people in the FSU did mess with the Kit because when it was the SU, that's all they could do. Effectively, we are only undoing others mistakes. There are several problems which cause the focus inaccuracy. One is tampering and people doing things without realising the repercussions. The second is the way there are made. Comparing an FSU lens with a Leica one is like comparing a tractor with a Rolls Royce and a soviet tractor at that. The age probably has less to do with it than the other factors.

As to getting a pro job on it, my usual camera tech won't touch them or the early Canonets etc. Not because he can't but he feels it is wrong to charge someone twice the value of the camera to fix it. That is how I got started - because he encouraged me. Allright, I have had 30 years experience in model engineering and I have built my own car but until then, I thought it best to leave to the pros. The argument about the legal proffession taken to it's conclusion would also mean we shouldn't do any woodwork, home improvements etc. The real art is knowing your limitations and when to call the experts. I have built all sorts of furniture, knocked walls down, done plumbing jobs etc but as soon as electrics are involved, the "expert" gets called.

Kim

I'm still shaking my head over the fact that so many FSU camera owners seem to be do-it-yourself-ers. Apparently the relatively low cost of the machines tempts people to figure that if something is out of whack, it can be replaced if there is a screw-up.

But there seems to be a continuing discussion about accuracy of focus on the cameras. This could a matter of the age of the equipment, right? Chances are the Russkis didn't plan on the adjustments possible on older Leicas when a CLA is done. And how many would go to work in the evening on their own M-3??

I've read in photo magazines that any amateur "repairing" a camera is akin to the guy who serves as his own attorney - he has a fool for a client. But it seems to be almost endemic with FSU cameras. Granted, I've seen "Leica repair manuals" on eBay and other sites, but I'm not tempted to play with my M4-2 or with a Zorki.