Jupiter-8 (with fungus) at f2.8

alex ph · Joined: 16 Mar 2013 Posts: 1571

This is Jupiter-8M on Contax-Kiev mount, produced in 1974. There are several threads here about the lens, so I decided not to hijack any of them. What is particular for my copy, it has a fungus inside, not the one which spreads itself on the lens surface, but some type which fills in the volume between the lenses with dozens of tiny transparent filaments. When you look inside the lens, you may see these subtle "crystals". But I did not manage to catch them in a shot. Otherwise the lens is in a perfect state.

First I thought that the fungus should ruin definitely the lens as an optical instrument. But when I started using it, I was impressed by the fungus' weak (if existent) impact on image. It makes think more about the way dust affects the lens. Many people say, in no way. I read that some lenses with fungus give a special softness and glow. And I was curious if I could have such an effect. So I fixed the aperture on f2.8 and took several shots to capture close and distant objects. After all, I'd say the lens performs very well and surprisingly sharp as compared to my previous idea about the "soft Jupiter-8".

Here are some shots, slightly tweaked for contrast and colours, then resized:

#1 - a nice and easily corrected colour rendition

Crop from the center of the shot above, no post-processing

#2 - bright light performance, strangely, flare is not really present in shots exposed to sun

#3 - performance at a mid-range distance, with a rather pleasant soft rendition of the background bushes

#4 - a close distance shot

Crop from the centre of the shot above, no post-processing

#5 - performance in a high contrast situation

Crop from the centre of the shot above, no post-processing

And another small crop, just an impressive rendition of the plant "hairs", so the focus is closer to that point, I think

#6 - rendition of distant objects, always at f2.8

And a crop from the centre of the image

alex ph · Joined: 16 Mar 2013 Posts: 1571

I add here a shot of the fungus that I managed to get. It was not easy to seize the sun reflection on these tiny capillary forms. Not the best shot, I admit, though it gives an idea of the fungus type:

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

Great captures, doesn't look like the fungus at this time affects the imaging.

It doesn't look too heavy, and should remove with ammonia and alcohol solution.

ForenSeil · Joined: 15 Apr 2011 Posts: 2726 Location: Kiel, Germany.

Reminds me of my J-8 with fungus Very Happy

Though the IQ of my copy was already much worse
The J-8's seem to be slightly prone for fungus between these two elements.
http://forum.mflenses.com/fungus-in-lens-apo-rodagon-r-75-4-on-bellows-t52772,highlight,%2Bfungus+%2Blens.html
http://forum.mflenses.com/a-lens-without-fungus-t52407,highlight,%2Bfungus+%2Blens.html

alex ph · Joined: 16 Mar 2013 Posts: 1571

Thank you, WNG555! I never tried the mixture you mention. If I apply it, will not the cleaned lens become indecently sharp?! Just kidding...

ForenSeil, in no way this subtle fungus goes in pair with your royal tree! You must be right about the lens construction which facilitates the parasite flora. I should have courage to open the lens and try to serve it with a fungicide.