Canon f/1.2 report

[Mackinaw]

The element directly behind the aperture blades constantly fogs up on my 50/1.2 too. It's hard to believe that a lens made back in the 1950's would still be outgasing, but I guess so. I've learned to live with it and accept the fact that I'll have to clean this lens about twice a year. Luckily this is an easy job that takes me less than ten minutes to do. A minor hassle, but well worth it considering the images I get with this lens.

Jim Bielecki

 

[jlw]

Hmmm, odd. I've owned two examples of this lens (one in the past and one currently) and both have been fog-free. Maybe I'm just lucky.

You guys don't store your lenses in sealed plastic bags between uses, do you? Polyethylene definitely will "exhale" a plasticizer that will collect on lenses as a milky haze. If you use a plastic bag to protect a piece of equipment against dust, leave the bag open at one end.

 

[Sonnar Brian]

It might be useful for people to post the Serial Numbers of the lenses that have the fogging problem. Canon may have changed the lubricants/cements or whatever else could be causing the problem. This occurred on the Canon 50mm F1.2 that I had. Most of the haze cleaned off but some lubricant got into the balsam and discolored it. It was oily, and I assumed it was from the focus helical. A lot of the lubricant had built up, some "oozed", and was seeping into the lens module.
Some pictures from the ad, with an attachment wide-open.
http://www.rangefinderforum.com/forums/showthread.php?t=6165&highlight=canon+f1.2

Ealy Nikon AID lenses are notorious for aperture blade problems. The AI lenses that preceded them were fine, and later ones were fine. For about 2 years Nikon "experimented" with some (damned) lubricant that got onto the blades and freezes them. Almost impossible to get rid of it all; paid for a cleaning on a 50mm F1.4 AIS series Nikkor. Within a year the blades froze up again. I use it on my Nikon E3 which uses all lenses wide-open and has a second (internal) aperture mechanism.