How to reverse lenses question

[hockeyplaya13]

Ok, I've read about some of you taking a lens, say a 50mm 1.8, and attaching it backwards to another lens, say a 200mm 2.8. My question is how exactly are you attaching it? What do I need to have in order to do this? Thanks!

[Mark1]

Google "reversing ring" It basically is a filter without the glass, and with threads on both sides. You mount the lens nose to nose and then to the camera. Set them both to infinity and enjoy.

[hockeyplaya13]

Oh sweet, that's easy enough. Thanks!

[LordV]

Just make sure you are looking at a male/male reverse coupler that should have filter thread sizes to match the lens filter sizes you are playing with. If you can't find and exact match you may need a filter stepup/step down ring as well.
Brian V.

[hockeyplaya13]

Stepup/Stepdown rings would be used if you were using two lenses with different filter sizes?

[LordV]

Stepup/Stepdown rings would be used if you were using two lenses with different filter sizes?

may not be necessary- you can often find reverse couplers with the correct filter sizes without needing step/stepdown rings- it's just in case you can't find one with exactly the right thread sizes.
Brian V.