I just picked up 2 Tiffen conversion lenses to go on
my Canon Powershot G2 with a Lensemate Adapter. The adapter
is 49mm (female) and the conversion lenses are 43mm (male).
I've found a few on-line dealers of step-up/-down rings,
but I'm a bit confused by the terminology. One dealer sells
step-up rings in 43mm to 49mm, and step-down rings in
49mm to 43mm. There is a $3.00 difference in price, so I'm
guessing these aren't the same thing.

Does anyone know which I need, step-up or step-down? And
what's the difference?

I'd hate to wait for the thing to show up, only to have to
send it back and wait again.

Thanks

What if one has this collection of 43 diamater lenses! That way one does not loose the functionality of ones older lenses. Mikes sence to me. Bsteph

Mikes sense? Is that another oxymoron?!? lol (",)

Thanks Alpha, I'm not sure which lens you're asking about so I took a shot of the setup. The cylinder is the Lensmate, which screws onto the camera around the fixed lens. On it's end are 49mm threads to take filters. The Tiffen conversion lenses are shown face down. They have 43mm threads just like on a filter. So I need to screw the conversion lens into the adapter just like a filter.

It's true that the conversion lenses are
smaller in diameter than the Lensmate adapter, but that's
the largest size that the conversion lenses come in. Brief
tests here show that only the telephoto converter has any
vignetting.

yup, a step-down is what you need, 49>43 - I'm going through an extremely similar thing to get my 49mm filters to fit my 52mm tube....shop was out of stock though. Bummer. (",)