Older lens is foggy

I recently came across an older Canon 35-80mm lens that I thought I had lost. It's been in a bag attached to an Elan for probably 5 years. When I put the lens on my Rebel and looked through the viewfinder the image was kind of hazy / foggy. I took a couple of pictures and they show what I was seeing. I cleaned the front and rear glass and it's still the same. Does anybody have any clue as to what it might be? The bag was in my house the whole time and it wasn't exposed to any excessive moisture.

Thanks for your help.

Mark

Have you held the lens up to the light (not the sun) and looked through it?

Lenses kept in bags and locked away suffer from poor air circulation, which can lead to trapped moisture and worse - fungus.

Light and dry conditions are the enemies of fungal growth. Older lenses that used to yellow due to glass coatings can be treated with UV lights, but leaving it in a bright windowsill with the caps off for a few days will have the same effect.

Pop the caps off, put it in the sunlight and leave it for the weekend. Check it on Monday. The heat from the light will help drive off moisture (if that's what it is) but if it is fungus (look for patterns or etching on the glass) do NOT mount it again and toss it. Do not store it with any of your other equipment.

Thanks for the replies. Moisture and any type of mold / mildew / fungus was what I was afraid someone might say. I'll try putting in a warm sunny window and see what happens.

Thanks again,

Mark

My original EF 35-80mm f/4-5.6 lens was quite hazy and gave very low contrast pictures. The front and rear elements were fine too. Shining a light into the back of the lens showed that it was one of the internal elements looked very dusty or fogged somehow. I carefully disassembled the lens down to the problematic surface and cleaned it with a microfiber cloth and lens cleaning solution. After it was reassembled it worked fine again. It is a quick job. Probably a local camera/lens repair shop could do it for a few dollars too. I don't think it was fungus in mine. I think it was some kind of oxidation on the internal lens. There wasn't any pattern to it, just a uniform haze.

I've never heard of lens fungus spreading to other lenses in real life. Fungal spores are all around us and surely in all of your lenses already. It takes the right conditions of humidity and temperature for them to grow. Maybe consider getting one of these for your camera bag to prevent those conditions from happening.

Even lenses that have fungus growing in them can still be cleaned. If the fungus has etched the surfaces, the lens may lose some contrast but still be usable. Often they can be cleaned up to work fine again.

Post #2832 in the link below shows a lens with considerable fungus growth, but the photographs taken with the lens shows no sign of a problem.

I have a Tokina FD lens which had been stored in my roof-space for about 20 years. When I dug it out, it also had fungus on the inside of the front element. I removed the front element and cleaned the glass, all is now well.

https://photography-on-the.net …ead.php?t=64427​7&page=189

macroimage wrote in post #13389175
...
I've never heard of lens fungus spreading to other lenses in real life. Fungal spores are all around us and surely in all of your lenses already. It takes the right conditions of humidity and temperature for them to grow. ...

Yes, exactly my thinking.
Sometimes I see on flea markets photo bags with all lenses with fungus - but I suppose that they all are stored in that bag in the same bad conditions.
I own 100+ lenses, some of them with fungus - not problems with fungus spreading.
I have one lens that got fungus - it was stored in the basement, and there was a incident with days of 100% humidity and 30°C temperature. It got fungus. It was the single lens there - and up to that time I had no other lens with fungus. And that was one of the 4 lenses I bought new about 20 years ago.