UV black lamp use on Takumar 50mm F1.4

beachboy2

I have been trying to bleach yellowing of Super Tak lens. Some hot sessions in the sun seem to be too much risk from lens overheating. I found a 20 watt compact fluorescent UVA party light bulb ('black lamp") at the local hardware store. Cost was AUD $17.50, or about USD$16. I mounted the bulb in a desk lamp, aimed it down into a foil covered bowl with the Super Tak at wide open aperture. Distance was close with a few centimetres gap between lamp and bowl to enable air circulation. Now 73 hours later, yellowing of lens is almost gone. Will do another few days and report whether yellowing dissappears completely.
bb2

eeyore_nl · Joined: 09 Nov 2008 Posts: 837 Location: Netherlands

beachboy2 · Posted: Sun Feb 28, 2010 7:30 am Post subject:

The reason for using the party light was that the price was good. Lens fitting is standard bayonet or edson screw type, so any handy lamp could be used. Another 12 hours or so and I have decided my Super Tak is free of yellowing!
bb2