> How does it attach to the camera? Does it take up the hot shoe? Nope. It slides down onto the viewfinder (which, as you probably know, has grooves on it for such accessories).
> Have you ever used one before, and do they really work? Well, yes and no. It doesn't directly affect focusing, of course. However, for those times when focusing needs to be critical, it helps by magnifying the center of the viewfinder. > Also, How would it work? It's not coupled to the lens in any way, > is it? Nope. It's strictly an external attachment to the viewfinder. > I'd guess that it's for a screwmount, probably a Spotmatic. The one shown in the eBay ad looks like the one that fits on the screwmount bodies and the K-series of bodies. There are two newer ones that (both) fit everything newer, starting with the M-series bodies and the LX. One came out with the M-series bodies, and another one came out with (I think) the SFX/SF1 bodies (but they are interchangeable). I think that the oldest (M42 and K) version uses a chrome clip to slip onto the viewfinder, while both of the newer ones (I think) use a black clip. > It's a focusing aid that slides over the viewfinder. It flips out > of the way when you don't want to use it. Yes indeed (unless you have a flash unit mounted on the hotshoe - <g>. (Actually, with the offset hotshoe on some bodies (e.g., the SFX/SF1), perhaps that's not a problem in some cases (?)). Actually, the same functionality (magnifying the center of the viewfinder, not the "flip[ping] out of the way" - <g>) is available with the Refconverters M and A (in their 2X position), but at a right angle, of course. Fred
