Jupiter-9 f/2 85mm LTM (M39 Leica screw mount) revisited

There have been several postings in this forum concerning mismatching

helicals of the Jupiter 9 f/2 85mm LTM lens. I recently dissambled one

of these to remove a fungus spot inside.

 

Actually these lenses have two helicals, but you will find this on

some other LTM lenses, too, since a second helical is required to move

the rangefinder coupling ring. This coupling ring needs a displacement

equal to the displacement of the lens barrel of a 50mm lens, and the

displacement of the lens barrel of 85mm or 135mm is much bigger.

 

I don?t think that different thread pitches are used on different

items. Also, the double helical is not a big problem to cope with. The

problem with the Jupiter lens is that NOTHING is adjustable. It seems

to me as if the threaded holes for the stop pin of the (internal)

focussing ring and the coupling pins between the two helicals and

their respective tubes are drilled ?to fit? during the manufacturing

process, i.e. there are no fixed positions, and the proper positions

are determined during the adjustment procedure.

 

On some other lenses of other manufactures I found the focus ring and

the rangefinder coupling ring adjustable ? both can be done without

big problems. To adjust the focus ring a LTM camera with removable

back or swing loading door is very helpful.

 

The more or less arbitrary positions of these pins on the Jupiter-9

can cause some trouble when reassembling such a lens if you did not

mark carefully the position where the moving parts come off their

(multi-turn) threads. A rangefinder coupling tube assembled the wrong

way will quite obviously give severe errors in rangefinder readings.

Reassembling the focussing helical the wrong way will probably not

result in severe focussing errors but it is just a game of luck

whether this erro is caused just by wrong assembly or by using

non-matching components (see below). Of course you can loosen the

focussing ring and try to adjust it but in this case the infinity and

close-up stop will be out of alignment ? different from most other

lenses these stops are provided internally and NOT via the focussing

dial.

 

I have heard that some folks shimmed the optical block ? it is just

screwed onto the rear lens body (on my item there were no shims

between the body and the optical block). But in this case you will

have to change the position of the focussing dial against the internal

focussing rings. On my lens I could clearly see the pits caused by (or

provided for) the set screws holding the body and those holding the

focussing dial, and they seemed to be in the position provided by the

manufacturer. Also, shimming the optical block will also change the

position of the rangefinder coupling ring, and, again, this is not

adjustable if you don?t drill new stop pin holes (or grind down the

coupling ring).

 

A lens assembled from parts from different lens items is another

story. Depending on the tolerances between lenses, these parts (or

rather the positions of the pins) will match more or less, and a

rangefinder reading and/or focussing error will not be very obvious.

However, if you run across such a lens which gives inaccurate readings

of the rangefinder, do NOT buy it ? it is NOT possible to readjust it

unless you have the means to adjust it correctly with the pins off and

drill your own threaded holes after proper adjustment. It IS possible

that the rangefinder coupling parts (and/or the focussing helical) are

just assembled the wrong way round but there is no way to check this

on a shop counter, let alone from an e*bay description.

 

A lens which has some play in the focussing mechanism is not a big

problem. I could cure this on my item by tightening the two coupling

pins which appear in the slots close to the rear end when you remove

the rear lens body. Set the lens to close-up focus and remove two tiny

set screws close to the edge of the focus dial, and unscrew the rear

body shell. When reassembling, screw up the body part up to the stop

but take care that the set screws meet their original positions. You

can check this by turning the focus dial to oo, it should meet the

mark on the body shell.

 

Winfred; do yopu have a black or chrome model?<BR><BR> The two black models I have are from the 1970's; the chrome model is from 1959; the 1 of the 3 that focuses and tracks correctly. <BR><BR>The chrome lens is stiff; and probably never was rebuilt; the two black models came relubed; and had very serious focus problems. <BR><BR>Re <i>The problem with the Jupiter lens is that NOTHING is adjustable</i><BR><BR>(1)The black J-9's have a very fine pitch thread on the lens block; anc the entire assembly can be adjusted for spot on infinity focus; at infinity; at the film plane; when the lens is set to infinity.<BR><BR>(2)Then the rubic cube helix deals are fooled with; and hopefully the lens focus cam cylindrical ring can be set correctly. Both of my black models have a index that almost makes the rangefinder align; but no cigar. The other positions are way off. If left at the "almost ok" position; mine have a worsening focus error; because the focal length ot the lens block doesnt match helixes pitch. In Leica; my 50mm F2 summicron is a 22; meaning a 52.2mm focal length. With a Jupiter-9; either they dont do matching; or got them all mixed up when relubing. My two have alot of error. Even if a camera is adjusted to match the bastard Jupiter-9; both of mine misstrack at closer distances. One can adjust the cam length of a camera to force the camera to track a bastard lens. But then one has a camera that wont track with a stock Summicron. <BR><BR>One can custom lap the J-9's ring to make the rangefinder work at infinity. One of mine then actually requires more material on the ring when close up. The other I have not tried lapping yet; it missfocuses abit at infinity; and alot when at close distances. <BR><BR>I find it odd that some folks actually believe that a camera repair person can "fix" a lens that is a bastard; with its focusing cam helix moving at the wrong rate for the focal length of the lens. There is not "adjustment" on my two black J-9's for this grave error; except for custom lapping of the cam surface; which is a slow go.

(the older chrome and newer black J-9's have slightly different parts; and mine wont interchange)

Sorry, I did not mention that I was referring to the chrome version (mine has a 1961 serial number).

 

I have seen that there is a very fine thread linking the body with the optic block, on my item this is screwed down to the stop, and probably focus adjustment is done by drilling the focus stop pin thread in proper location. It might be possible to adjust the focus using a shim etc but this will cause more problems with the rangefinder coupling.

On of mine had a shim; the other didnt. The one without the shim required the optical lens block to be rotated outwards; away from the film; for infinity focus. The lens block must be in focus at infinity; when the lens is at the infinity stop; before the rangefinder is checked. The lens should properly scale focus at infinity; even if ones rangefinder is broken. On mine as a lark; I adjusted the rangefinder to match at infinity; then set the lens focus at the film plane at infinity. It still misstracked at closer distances.

I have checked the rangefinder coupling and the actual focussing of my Jupiter-9 now. I made this with my FED1 and my Canon7s (the rangefinder of the latter is less accurate due to less magnification - it does not have a separate rangefinder eyepiece). With the two Canon LTM lenses I have (f/1.8 50mm chrome and f/1.2 50mm black) I read a distance of 5.5 ft (1.68m) on both camera bodies (the f/1.2 50mm does not fit the FED1 body due to its thin rangefinder coupling ring which does not meet the pointed FED1 cam). The Jupiter-9 focussing scale indicated something close to 1.8m on both bodies. With a split-image focussing screen across the film screen (fortunately the Canon7s has a T setting which keeps the shutter open until you set the speed dial off this setting again), and as far as I could see the Jupiter-9 was almost dead on, maybe actual focussing was a bit closer than 1.8m (6 ft). I will try to figure out whether this focussing error might be due to rangefinder calibration for an actual focal length of 52mm, as some people suspect.

 

However, as mentioned by others, there is no cure for a rangefinder coupling which is dead on on oo and off at closer distances other than recalibrating the rangefinder mechanism of the camera which, of course, will be misaligned for rangefinder couplings based on a (slightly) different focal length.

Hello Dear Mr. Buechsenschuetz,

I'm an owner from a Jupiter 9 Leica M 39 mount in silver condition with Nr. 59 XXXX. I have a problem with mechanical helical not satisfied for self repair. Is in fact is horribel assampled the lens.

But a specialist for russian cameras repairs take the Jupiter 9 in condition in 100 % are ok, and works very well.

Thank you for your advise a different problems with a Jupiter 9.

I have never hear from the problem. Is your opinion the plant

producer change mechanical determinatet ?

I would not say that the manufacturing and assembly quality of my Jupiter-9 sample is that bad. Actually I did not find any mechanical flaws except slightly worn guide slots for the mentioned stop pins. It seems that these guide slots cause a lot of friction - without the guide pins the helicals move very smoothly after I washed out all the old grease and replaced it with a dose of graphite powder and some silicone oil. (I tried silicone grease prior to that - it does a nice job in quite a few helicals I regreased - but I found it added an amount of friction or rather dampening and the lens was very hard to focus.) BTW there was old grease everywhere inside the lens except for the lens surfaces - it seems they coated every surface with a thick layer of grease. There are even residues of dried up grease on the outer chrome parts which are hard to remove.

 

I think that the differences in focussing at close-up distances are due to the mechanical design. I don't have the means to determine actual focal length of a lens system, but it makes me think that the standard lens for the FED1 has 50mm nominal focal length but some other standard russian LTM lenses (such as the f/2 50mm which sometimes comes with the Zorki-3) have 52mm nominal focal length.

Hello I also have a black jupiter 9 with focusing problems,

I found this site...I still haven't taken the lens apart for adustment,but I will soon......this site seems quite good....

 

http://www.pusang-puti.0catch.com/page26.html .........

 

 

scroll down and go to "Prime Objectives" then scroll down again and you will see a picture of the jupiter 9...click where it says focusing problems.....

good luck

Vist Russian camera message board on www.beststuff.com It has had many many years worth of messages dealing with bad focusing Jupiter-9's in LTM. There is no repair on 2 of my Jupiter 9's possible. The lens block's focal length does not match the pitch of the helicoid.

Also see Dante Stella site concern RF lense incompatibilities.

 

http://www.dantestella.com/technical/compat.html

Here I have a mess of Russian lenses; over a dozen of them. Many track perfectly with Leica equipment; and are spot on. <BR><BR>The Jupiter-8's I have the most of; and are the most consistant lens. The Jupiter-9 is the worse; 2 or the 3 of mine are missmatched. <BR><BR>The better lenses of mine are mostly 1950's lenses.<BR><BR>The worst are 1970's vintages. <BR><BR>It is hard to believe that the Russians who made great lenses in the 1950's; that matched with my Leica; purposely decided to make them in compatible 2 decades later.<BR><BR>The pre WW2 Russian stuff might no have been built to a nominal "Leica" dimensions. But ALL of my 1950's Russian lenses are decent. <BR><BR>