I fixed a couple of lens by leaving them on a south facing windowsill for the summer. I had two M42 lenses for my Pentax Spotmatics with radioactive glass. In the 1960s radioactive glass was used in a variety of high end lenses because of its improved refractive properties. The problem with this glass is that it turns yellow with age. I picked up, at a very reasonable cost, a yellowed Pentax Super-Takumar 35mm/f2 and Pentax Super-Multi-Coated Takumar 50mm/1.4. Both are very desirable lenses but perhaps lens desirable with a yellow cast unless you like to shoot black and white with a yellow filter. Various forums indicated that copius amounts of UV would remove the yellow. I put them under a UV lamp for 3 weeks. Looking through the lenses it appeared that the yellow was reduced. I put them on my Pentax *ist DL digital SLR.

I compared the 50/1.4 to my Pentax Super-Multi-Coated Macro-Takumar 50mm/f4. The 50/1.4 was still very yellow. At the beginning of summer I put the yellow lenses on a windowsill and left them there until two days ago.

I wonder where the yellow went? Success! Now I have to straighten out the filter ring and it will be as good as new. A great lens. It might be interesting on my Pentax DSLR since, with the 1.5 crop factor, it's equivalent to a 75mm lens. A 75mm f1.4 lens.

I compared the 35/2 to my Pentax Super-Takumar 35mm/f3.5. The 35/2 was even yellower than the 50/1.4.

A summer on the windowsill cleared out the yellow. Now I have two great lenses.

Both these lenses were from Vern's stash he got from a collector friend who died. I went down to his storage and found a couple of interesting cameras.

It's an Olympus Pen EES half-frame 35mm with auto-exposure powered buy a selenium cell. No batteries. Solar powered! Built between 1962 and 1968. A 35mm negative is 24mmx36mm. A half-frame 35mm negative is 24mmx18mm. 72 exposures on a 36 exposure roll. It's a vertical format camera. I've got it loaded with some Fuji 160s.

The other is a Kodak Special Six-20 made between 1937 and 1939. It's the smallest camera shooting 6x9cm negatives that I've seen and the Anastigmat lens is sharp stopped down. I took the lens cells out and cleaned them. I still have to put the shutter back in, respool some 120 roll film on a 620 spool, and I'm ready to take some pictures. I will start out with some Ilford HP5.

And I've rearranged my office which means I'm pretty close to setting up my printer.