Thorium in Jupiter 9?

mszargar

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Hi

Is it a known issue for the J9s to get yellow (the optics, of course), like the older Takumars do? I have a copy that I think is pretty yellow, and I am wondering whether I have to send it back or do the ultraviolet treatment.
 
I don't know where you live, but here in Arizona I've had great success de-yellowing using sunlight. Tip: Remove both lens caps, then wrap the lens in aluminum foil, shiny side toward the lens. Then cut out around the rear of the lens so sunlight can come in through the rear element. Wrap a few rubber bands around the lens to hold the foil in place.

Prop the lens at about a 40 degree angle facing South. Sunlight will enter the lens, strike the shiny foil covering the front element, and light rays will bounce around inside the lens and hasten the clearing process. Also, the foil around the lens will shield the outside of the lens and keep it from getting hot.

It works, and I've had people who live in overcast areas send me their lenses.

Ted
 
Mine (m42 from 1971) has no signs of yellowing or any other such deterioration, although I wouldn't mind - my I61 has some yellowing and the contrast is unbelievable. If you like b&w this can actually be a good thing.
 
I believe that the one I have is yellow thanks to it's intensely blue coatings, not because of it's glass. Later, better coated Jupiters look neutral to me, and are more contrasty an flare-proof as well. I've never heard of thorium used in a soviet rf lens, and just one of them used lanthanum: the I-61 L/D.
 
Mine is a 62, and it is true that it has very intense blue coatings. I haven't tried it yet with a color film, but I guess I should. I am in Montreal, so, not much chance with natural deyellowing.
 
Yellowed J9

Yellowed J9

Here are some shots to illustrate my issue:

Two shots with Jupiter 8: [1 / 2].

The same shots with Jupiter 9: [1 / 2]

Please don't be picky about the focus: these are unadjusted russian lenses on a Leica body. You don't get correct focus unless if you adjust them.

What do you think? Is this copy a keeper, or I have to send it back home?
 
Lenses vary slightly in colour rendition and in this case the J 9 seems to give a warmer look. Unless you want to use slide film or print directly from a colour negative then the colour balance could easily be adjusted with software. Whether you keep it or not is not something anyone can decide for you, but I can't see that you have grounds for a complaint to the seller.
 
Crystal clear acrylic lens cements only were introduced in the late fifties to mid sixties, and the USSR will have taken some more years to reverse engineer them. So they probably used the original Epoxy cements specified in the Zeiss designs, or reverted to Canada balsam. Both have a tendency to yellow (and may even go deep brown or black, in thick layers), especially if assembly issues created a thicker layer than specified.

If it is yellowing (or rather browning) cement, a UV treatment will not help and might even make matters worse.
 
Thanks for the comments.

@fanshaw: Actually, I do shoot slide for color, and negatives for b&w.

@sevo: It is not improbable what you mention. Just that I have never ever heard about cases of yellowing Jupiters... Maybe I am not well-informed, but I find this case very particular. I have been searching over the net, to no avail.
 
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