Extension Tubes
Extension Tubes Extension tubes are just that, hollow tubes that
are mounted at the back of a lens to make them higher powered. A
200mm lens is just a lens with a built-in extension tube but it is a
tube that was factored into the actual lens design from the get-go
and carefully balanced. It is said in defense of extension tubes that
they do not mess with the lens quality because they contain no lens
elements themselves and that they only add ‘extension’.
Well, not quite. The long and the short of that argument is that
extension tubes throw a lens out of balance just as add-on close-up
lenses do. The result, once again, is a degraded image. An
extension tube added to a lens to bring it to 200mm is not the same
as a 200mm lens with built-in extension. Try it for yourself. The sad
part is that before I could try it for myself I had to go and buy these
things and I got all of them I could find. Yes they work, but I never
use them, not even ever. I have been there and done that and it
was not nice.
Extension Tubes