A Problem Solved

I had a problem with my Nikon 500 mm mirror telephoto lens.  It came with a lens hood built in (a cylinder of aluminum less than an inch high) into which a lens cap was screwed.  But over the years of non-use the lens cap could NOT be removed - it seemed like the cap and the lens hood had been welded together.

Luckily the lens works OK without the screw in hood, so when I wanted to use the lens I just had to unscrew the lens hood.

None of the other Nikon or other vendor lenses I own have screw-in lens caps so I've never had this happen before.

I didn't want to use any kind of lubricant or penetrating oil on the cap and lens hood because I was worried that any residual oil might get on the lens and affect the coating.

So I finally decided to try heating up the lens hood in a shallow pan of water heated on the stove.  But since the cap and hood were joined so tightly it was impossible to heat just the lens hood.

Anyway, after 5 minutes or so I took the hood/cap out of the water, dried them off and then retried the Armstrong method (wearing gloves).  After several tries I was finally able to get them apart !  

A triumph over my aging lack of grip strength !

The screw in lens cap, lens hood, 500mm lens and a lens cap from a 55mm macro lens

In the future I plan to always back off 1/4 turn after threading on the lens cap fully.

Here is a picture I took of the moon, leaning on a clothesline, 1/500 sec.  I need to put it on a tripod !

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm