KECAY M42 (42mm) to 42mm Mount Focusing Helicoid Ring Adapter 17mm - 31mm(Black)

I like using oddball lenses on my camera's and I bought a couple of enlarger lenses 80mm and 105mm they have aperture control but no way of focusing this helicoid is ideal for the 80mm this sat directly between the body and the lens giving focus from about 1 meter to infinity for the 105mm i needed an extension tube but again this gave me a great focusing range. Basically a lens focus's at infinity at its focal length and to focus at 10x its focal length distance it needs to be 10% further out. so for 80mm to focus from 80 cm to infinity needs 80-88mm or 8mm of movement for 105mm from 105cm to infinity 10.5mm of movement. This helicoid moves from 17mm to 31mm, 14mm of movement there is enough spare to make up for any inaccuracy in length with extension tubes. For macro work you can just add more tubes and focus with the helicoid. 2x would want the lens at 160mm from the focal plane for an 80mm lens (210mm for the 105). Shorter than 80mm lens probably couldnt get infinity focus on a dslr with 44-46mm registration distance but for a m43 camera with 19mm registration distance there are lots of lenses that can be used and m42 or m39 are quite common thread sizes a 39mm to m42 adapter is readily available. It's fair to say that modding and adapting lenses is addictive.

Very sturdy, great quality build. A smooth action and ideal for adding that little bit more travel to analogue lenses.

Bought this to experiment with vintage enlarger lenses on my Fuji m/less x system cameras, Fuji xf to M42 helicoid then lens, works great really pleased with it. Recommended

I use this well made helicoid on my MFT mount camera with a enlarging lens. Great performance. To mount the M39 enlarger lense you need onely a simple M39-M42 adapter ring.

Great product. Fast delivery. Thank you.

Works well, well built. Good product.

Very usefull with enlarging lenses.