znapper
Well-known
I know it has been done before ( http://www.pentax-manuals.com/repairs/j8service.pdf ), so this may just be a repeat to that.
I've tried to include my own experiences and pointers that can be good to know before you try to disassemble, clean and re-grease your Jupiter-8, especially if you have the complex helical variant.
http://helino-photo.blogspot.no/2016/01/how-to-clean-and-re-grease-two-jupiter.html
Sorry for the white-only text on background, hopefully people are still able to read
I've tried to include my own experiences and pointers that can be good to know before you try to disassemble, clean and re-grease your Jupiter-8, especially if you have the complex helical variant.
http://helino-photo.blogspot.no/2016/01/how-to-clean-and-re-grease-two-jupiter.html
Sorry for the white-only text on background, hopefully people are still able to read
Joao
Negativistic forever
Thank you ! The pictures are very clear and explicit .
johannielscom
Snorting silver salts
Hm. I'd like to get going on that with an old 1955 Jupiter-8 I have, it has slight fungus and oil in it but probably Zeiss glass (honey coloured coating, not blue) so worth the effort.
However, it doesn't unscrew. Totally stuck and I've tried everything except a full submersion in alcohol to loosen up the grease. Kinda partial to that, what if I do and cannot clean and assemble it again due to complexity...
Nice tutorial though, thanks! Bookmarked it!
However, it doesn't unscrew. Totally stuck and I've tried everything except a full submersion in alcohol to loosen up the grease. Kinda partial to that, what if I do and cannot clean and assemble it again due to complexity...
Nice tutorial though, thanks! Bookmarked it!
nukecoke
⚛Yashica
glad you've made manage to clean/ reassemble the early 1950s version. It took me long time to have it done too and I almost gave up half way.
I don't know if the early 1950s one is better than the other versions. One interesting thing is the coating "colour" onn mine is not purple-blue as I saw on my samples of other versions, but with gold-orange instead. But sharpness-wise I can't tell difference. A 1950s beat-up J-3 I have beat all four J-8s I have at f/2, so I use it more.
I don't know if the early 1950s one is better than the other versions. One interesting thing is the coating "colour" onn mine is not purple-blue as I saw on my samples of other versions, but with gold-orange instead. But sharpness-wise I can't tell difference. A 1950s beat-up J-3 I have beat all four J-8s I have at f/2, so I use it more.
znapper
Well-known
Regarding quality vs age, it stems from various discussions involving Mr Brian Sweeney and others that seem to know the history of the FSU-gear more detailed and that have worked on a whole heap of lenses, spanning the 50-60 year old history of the Jupiter lens.
According to the discussions I've seen, it seems that failure-rate in lenses made between the early 50's to the mid 50's (1956'ish) is very very low. "Most are excellent" is the common conclusion. It also holds pretty true to lenses made well into the mid 60's as well, albeit with a steadily growing number of failures and faults and quality issues.
The raw-materials (especially the glass) they used in the earlier lenses, was often German glass (or higher quality glass), I am not sure when they actually ran out of it though, could have been in use for only 2-3 years after the war, or well into the 60's, no idea.
From the discussions, it seems that until the end of the 50's, they even used German workers to produce a lot of the lenses.
From what I gather, after a while, the stock-glass and materials was produced in-country (doesn't have to be any worse than the German stuff though), the German part of the labor-force was replaced by Russian/Soviet ones. (probably from the end of the 50's to mid 60's if I am going to guess).
So, according to the know-how's, the quality and quality-control steadily dropped during the 60's, because it was often about number of units produced per worker, rather than quality per-se that was central.
Then there's the ideological factor; During the 50's, the Soviet ideology and morale was high, but once you hit the 70's and 80's, economy was bad, machinery may have started to be less precise/worn(??), materials and quality not so good and morale among the people and workers was low, which affected (again from what I gather from the discussions) product quality and quality control.
All this, seem to lead to the conclusion that
- Jupiters from the 50's have very little failure rate
- Jupiters from the 50's may have German glass (maybe more often between 1946-1955)
- Jupiters from the 50's may have been assembled and controlled by German workers (or a combination of Soviet workers, trained by Germans).
- Jupiters from the 50's to mid 60's seem to have less failure rate than later lenses.
- Lenses from the 70's and onward seem to have higher failure rate and less nice optical quality.
I have three lenses, one from 1955, one from 1963 and one black one, which I assume is from the 70's.
They are all pretty equal in terms of optical quality, hell the black one is both very nice optically and very nicely built. But the black lens is a much simpler lens, as the front rotates, there is not fancy helix construction, which is a little strange, since it's the newest model of them all.
1955 lens is the most complex one, concerning the focus mechanism, the 1963 is a simplified version, which works very nicely and is easier to produce and assemble, my 70's lens is a very simple design, with a rotating front. (but very light and actually, naturally, a tad shorter than the silver versions).
I am definitely no history-buff, and I've probably said stuff wrong in this post, but googling around and reading the old discussions on the subject is very interesting.
I would definitely LOVE to get my hands on a (great) Jupiter-3, I should probably buy one soon, as he prices increase these days.
According to the discussions I've seen, it seems that failure-rate in lenses made between the early 50's to the mid 50's (1956'ish) is very very low. "Most are excellent" is the common conclusion. It also holds pretty true to lenses made well into the mid 60's as well, albeit with a steadily growing number of failures and faults and quality issues.
The raw-materials (especially the glass) they used in the earlier lenses, was often German glass (or higher quality glass), I am not sure when they actually ran out of it though, could have been in use for only 2-3 years after the war, or well into the 60's, no idea.
From the discussions, it seems that until the end of the 50's, they even used German workers to produce a lot of the lenses.
From what I gather, after a while, the stock-glass and materials was produced in-country (doesn't have to be any worse than the German stuff though), the German part of the labor-force was replaced by Russian/Soviet ones. (probably from the end of the 50's to mid 60's if I am going to guess).
So, according to the know-how's, the quality and quality-control steadily dropped during the 60's, because it was often about number of units produced per worker, rather than quality per-se that was central.
Then there's the ideological factor; During the 50's, the Soviet ideology and morale was high, but once you hit the 70's and 80's, economy was bad, machinery may have started to be less precise/worn(??), materials and quality not so good and morale among the people and workers was low, which affected (again from what I gather from the discussions) product quality and quality control.
All this, seem to lead to the conclusion that
- Jupiters from the 50's have very little failure rate
- Jupiters from the 50's may have German glass (maybe more often between 1946-1955)
- Jupiters from the 50's may have been assembled and controlled by German workers (or a combination of Soviet workers, trained by Germans).
- Jupiters from the 50's to mid 60's seem to have less failure rate than later lenses.
- Lenses from the 70's and onward seem to have higher failure rate and less nice optical quality.
I have three lenses, one from 1955, one from 1963 and one black one, which I assume is from the 70's.
They are all pretty equal in terms of optical quality, hell the black one is both very nice optically and very nicely built. But the black lens is a much simpler lens, as the front rotates, there is not fancy helix construction, which is a little strange, since it's the newest model of them all.
1955 lens is the most complex one, concerning the focus mechanism, the 1963 is a simplified version, which works very nicely and is easier to produce and assemble, my 70's lens is a very simple design, with a rotating front. (but very light and actually, naturally, a tad shorter than the silver versions).
I am definitely no history-buff, and I've probably said stuff wrong in this post, but googling around and reading the old discussions on the subject is very interesting.
I would definitely LOVE to get my hands on a (great) Jupiter-3, I should probably buy one soon, as he prices increase these days.
EVIL_Guy
Established
My J-8 needs a new heliocid lubrification.
I still read a lot of helpful things all over the web.
But: My problem is the first step, screwing out the lens module.
In the videos I saw the guys screwing it out without any force.
Mine will not move anyway - Any idea/help?
PS: Yes, I took the right direction
I still read a lot of helpful things all over the web.
But: My problem is the first step, screwing out the lens module.
In the videos I saw the guys screwing it out without any force.
Mine will not move anyway - Any idea/help?
PS: Yes, I took the right direction
retinax
Well-known
Try household rubber gloves, they provide great grip. Iirc that's how I managed.
Ko.Fe.
Lenses 35/21 Gears 46/20
Sorry, I was not taking video while unscrewing it. It wasn't easy.
David Hughes
David Hughes
My take is that they fail due to wear and tear and so the older ones have already failed and been repaired (or sold off without telling what state they are in) but the newer ones haven't failed yet and the middle aged ones are iffy.
Look at the same thing happening to all makes but remember that they are not all the same age...
Regards, David
Look at the same thing happening to all makes but remember that they are not all the same age...
Regards, David
Greg Maslak
Well-known
I’ve just acquired a nice copy of the “simpler”, second sort of aluminium bodied Jupiter 8 described by “znapper” above. It bears a “No60...” serial number and came with a period, Russian yellow filter protecting the front element. All in all, a nice example, with smooth focus and aperture.
One thing. There is a tiny bit of movement between the thread mount ring and the lens, as if the thread ring is a bit loose. It rotates ever so slightly back and forth. The three screws holding the back ring are tight. Too tight to move! I would like to have a look inside and give it a clean. It’s a process I would like to learn and I think this is a good place to start. From the links, I can’t see much that could be wrong at the back, except wear on the guide pin and thread ring perhaps.
I’d appreciate any advise on how to best move the screws without stripping. Or whether I’d best leave well enough alone, since there might not be anything I can change anyway. Thanks.
One thing. There is a tiny bit of movement between the thread mount ring and the lens, as if the thread ring is a bit loose. It rotates ever so slightly back and forth. The three screws holding the back ring are tight. Too tight to move! I would like to have a look inside and give it a clean. It’s a process I would like to learn and I think this is a good place to start. From the links, I can’t see much that could be wrong at the back, except wear on the guide pin and thread ring perhaps.
I’d appreciate any advise on how to best move the screws without stripping. Or whether I’d best leave well enough alone, since there might not be anything I can change anyway. Thanks.
retinax
Well-known
When it's focused to infinity, you should see the guide pin and be able to determine if the play comes from it or something else. Mine has the tiniest amount of play there as well, I assume it's normal and harmless.
The screws on mine were no problem, those on the back at least. Does your screwdriver really fit? Next steps would be trying solvents or hear. But if you don't really need to get in there...
The screws on mine were no problem, those on the back at least. Does your screwdriver really fit? Next steps would be trying solvents or hear. But if you don't really need to get in there...
Greg Maslak
Well-known
Thank you, retinax.
Upon inspection of the pin at infinity, all looks OK, just a bit dirty. A #3 1.8mm precision screwdriver fits well and upon a careful try the screws move.
My experience is limited to M42 threadmounts. The Takumars I have are rock solid, but for now, I think I'll clean up the outside guk a little and just enjoy using the Jupiter as it is. I have a thrift store 50mm Nikkor F mount in disparate need of a relube. I think I'll start my lens CLA education there.
Upon inspection of the pin at infinity, all looks OK, just a bit dirty. A #3 1.8mm precision screwdriver fits well and upon a careful try the screws move.
My experience is limited to M42 threadmounts. The Takumars I have are rock solid, but for now, I think I'll clean up the outside guk a little and just enjoy using the Jupiter as it is. I have a thrift store 50mm Nikkor F mount in disparate need of a relube. I think I'll start my lens CLA education there.
ray*j*gun
Veteran
I have an Industar 50 (I 50) that has become very stiff and irregular. I love the lens but so far the only tutorials on re-lubing have been for the pancake version, I think the I 50-2. I don't want to hi jack the thread but would like to see a tutorial on this lens. I use it on my M8u and its a gem.
Kai-san
Filmwaster
Maybe this is what you're looking for:
https://tomtiger.home.xs4all.nl/zenrep/indus.html
I did mine according to this recipe, no problems.
ray*j*gun
Veteran
Prefect thank u.