BBbuilder467 wrote:
Just for curiosity, I'd like to reverse a Pentax 50mm SMC-M, all manual lens to my micro 4/3.
I can't remember if I need to reverse directly to the body or reverse to the adapter to get the 1:1 magnification.
Has anyone tried it? With extension tubes, I need to use the adapter to get accurate ratios, so I assume I need to reverse to the adapter. I'd need the reverse mount for Pentax K instead of m4/3?
I know some people love using legacy lenses, both the right way round and reversed, but I've never had much success with them. However, having experimented with them I do have some legacy lenses, adapters and reversers so I just did an experiment.
I reversed a 28mm Minolta lens on to a G80 using a Fotodiox MFT reverse adapter. This reverse adapter has an MFT mount on one side and a 58mm male thread on the other side. I used step rings to marry up the thread on the adapter with the filter thread on the lens. At infinity focus I got a scene width of around 14mm, so slightly more than 1:1, with a working distance of around 30mm, which is very small. Going to closest focus didn't change the scene width but slightly reduced the working distance to around 25mm.
Doing the same with a 50mm Canon FD macro lens I got a scene width of 40mm, so less than 1:2 with a working distance of around 160mm at infinity focus, and at closest focus a scene width of around 38mm with a working distance of around 120mm.
I don't understand what you have in mind for "reverse to the adapter". An adapter (that is, an ordinary, non-reverse adapter) gives you the mount for the lens type you want to attach, with the lens used the right way round. For reversing, whatever lens you want to reverse you use the same reverse adapter and then use appropriate step rings to attach it to the filter thread of the lens you are reversing.