[davidmanze]

 I didn't shut an eye either!  I used the 500mm F4 for semi macro for butterflies with I think 30mm of extension tubes.

 

  Brilliant link to element gluing BC, I would never have thought of that and it's cured by UV and available in your local DIY store, like how sweet is that?

  I'm not sure how the acetone is doing but actually the element looks a little less cloudy, probably my lack of sleep, if you stay awake long enough even kit lenses look sharp.  B)

 

  Thanks again for to tip!