Hyperspeed Hiccup.

[Paul Bruening]

I got this dirt-cheap tele-extender in the mail today and benched it in reverse to see if it can squeeze an SLR's image down. It doesn't. It acted the same way in both directions, expanding the image instead of contracting.

 

Is there a difference between a tele-extender and tele-converter? Am I using the wrong chunk of glass for this experiment?

[Chris Keth]

I think it's working like it should. You can't just take a negative focal length lens (which it is if it's enlarging the image) and flip it around and expect a positive lens.

 

If you want to make a smaller image come out the back of a lens, you would want some kind of a complex planoconvex lens, I would think.