Bubbles in Jupiter 9

F

fuzk

Established
Local time
7:22 PM
Joined
Oct 16, 2008
Messages
88
I was looking for a Jupiter 9 lately and chanced upon one that was described with having bubbles in the lens. Curious, I did a quick search and found 2 somewhat different views (although I must admit, the negative view was about another lens) regarding bubbles in the lens.

One side said that bubbles in the lens equates to good quality due to the manufacturing process and the other, you guessed it, bad equality due to the same thing.

Can someone enlighten me what these bubbles are? And will they actually affect the final picture? Since I'm already asking questions, I might as well ask if anyone has a spare Jup9. I'm not sure how safe the ones I found on the *bay are.

Thanks in advance. :)
 
From another thread in this forum:

http://rangefinderforum.com/forums/showpost.php?p=1100565&postcount=6

The instruction manual of the FED camera from 1952 says this about bubbles (the following is a translation using google):

Preparation of special grades of optical glass presents significant technical difficulties. In particular it is difficult, and for some grades of glass it is impossible to get rid from air bubbles, formed in the mass of glass during smelting. Present methods of elimination of these bubbles in some grades of optical glass made by us or the foreign technical equipment of glassmaking for the present has notbeen achieved. For these reasons in lenses of complex (difficult) foreign and Soviet objectives always it is possible to notice a quantity of bubbles. In itself bubbles practically do not influence quality of objectives and sharpness of pictures, and, hence, objectives with bubbles on lenses at all are not defective.
Click to expand...

If you find some bubbles in the lens, it would mean that the lens actually passed inspection. Small bubbles are really insignificant- and invisible- for that matter- in as far as the lens or its function is concerned.

I have lenses with bubbles too- Leitz Summitar, Jupiter-3, and others.

Having bubbles does not "equate to quality". However, in their time, some types of high quality glass are difficult to prepare without forming bubbles.
 
Ah okay. Thanks for the explanation. Now, to find a piece of quality glass... with or without bubbles!
 
Quality J-9

Quality J-9

fuzk said:
Ah okay. Thanks for the explanation. Now, to find a piece of quality glass... with or without bubbles!
Click to expand...

Bubbles aren't, and won't be your prime concern when J9 quality is the question. The LTM version of this lens is plagued by a lot of mechanically-induced focusing problems. Often, improper servicing is the cause. The triple helical used by the lens is a virtual rubiks cube were only one way of assembly will guarantee proper RF coupling, lens barrel movement to convert the RF camming to real focus positions, and the placement of the lens optic itself for proper focusing.

I've had about 14 J-9 at one time (now down to 7 in LTM, and some more in the Kiev/Contax, M42 and Zenit M39 mounts). 5 of the LTMs couldn't focus right when they arrived, and required some recalibration.

The best LTM J-9 I got is a $20 lens,- advertised as having a lot cleaning marks, with an intact barrel. Lens wasn't hazy at all, and in fact better than the others I got.
 
ZorkiKat said:
Bubbles aren't, and won't be your prime concern when J9 quality is the question. The LTM version of this lens is plagued by a lot of mechanically-induced focusing problems. Often, improper servicing is the cause. The triple helical used by the lens is a virtual rubiks cube were only one way of assembly will guarantee proper RF coupling, lens barrel movement to convert the RF camming to real focus positions, and the placement of the lens optic itself for proper focusing.

I've had about 14 J-9 at one time (now down to 7 in LTM, and some more in the Kiev/Contax, M42 and Zenit M39 mounts). 5 of the LTMs couldn't focus right when they arrived, and required some recalibration.

The best LTM J-9 I got is a $20 lens,- advertised as having a lot cleaning marks, with an intact barrel. Lens wasn't hazy at all, and in fact better than the others I got.
Click to expand...

Wow. It seems like bubbles are indeed the least of my concerns. Are there any way to see (from pictures) if a lens has been tampered with? Or do I really have to just take my chances?

What's a reasonable price range anyway? It seems that prices can vary quite a fair bit.
 
fuzk said:
Wow. It seems like bubbles are indeed the least of my concerns. Are there any way to see (from pictures) if a lens has been tampered with? Or do I really have to just take my chances?

What's a reasonable price range anyway? It seems that prices can vary quite a fair bit.
Click to expand...


It almost impossible to tell from pictures if the lens had been tampered. Even when described as 'serviced', again, it's impossible to tell whether the servicing it got was competent or not. All will be revealed only when you have the lens on camera, and seeing the sort of photos it makes.

That's the reason why I had so many J-9 at one time. I kept on getting another when the newly arrived one didn't quite work right.

Best to get from a reputed seller. Or one who knows about J-9. Most J-9 tend to freeze in time from fossilised lubricants. Some would take the lens apart, clean the helicoids, and then relube. Problem lies with the reassembly- it takes a lot of skill to put the three helicoids back, as well as the lubricant used. Modern slick lubricants will make the lens turn very smoothly, but the old helicoid design of LTM J-9 appears to rely on the dampening action of old, less slick grease for proper operation.

Price? 8 or 9 years ago when I was still getting them, they cost about $30-50. Now they range at under or maybe more than $100.

The 'white' aluminium barrel lenses tend be better than the black ones too.
 
Last edited:
I would not obsess unless there are lots of bubbles. Early lenses tended to have bubbles as the technology was not there to produce the better typeof glass without bubbles. So the story arose that bubbles are a sign of good quality glass. Which in its day probably was true. Fortunately we are beyond that now. Small bubbles will not affect the image quality.
 
ZorkiKat: Thanks for the very informative reply. That's why I'm always hanging around this forum. You learn so much. :)

Bill58: Thanks Bill (assuming that's your name). I'll have to go check out that website now.

peterm1: I'm not exactly obsessed about the bubbles. I was just wondering about the conflicting stuff I've been reading. We all know we can always trust the internet right? Heh.

What you said made me think though.

When did bubbles in lenses (on the J-9 particularly) stop appearing due to the advancement of technology. Or were they all made with the same methods of yesteryears?
 
A quick Google revealed this paper on bubbles and inclusions in optical glass (flint glass I think) . As I understand it in earlier days when refining techniques were far less well developed it was difficult to produce the glass blanks for lenses that had the required refractive index and other optical characteristics without bubbles occurring.

http://www.us.schott.com/advanced_optics/english/download/tie-28_bubbles_and_inclusions_us.pdf

You may find something here too but I have not read it all.....

http://books.google.com.au/books?id...8LyTCw&sa=X&oi=book_result&ct=result&resnum=1

Even today glass can have small bubbles - see page 20 of this link where the requirements for an allowable number of bubbles are set down.

http://www.hoyaoptics.com/pdf/OpticalGlass.pdf
 
ZorkiKat said:
Best to get from a reputed seller. Or one who knows about J-9. too.
Click to expand...

I agree, I bought two on eBay and both were unusable: first one had lots of scratches both on the front element and internal ones, the second had fungus and wouldn't engage the RF cam but for a little bit around infinity. Luckily, both sellers took returns, and I found someone selling one on RFF last week. Were it not for that, I'd still be looking for a good one.
 
You must log in or register to reply here.
Back
Top Bottom