Reversing 50mm?

RazorSharpWO wrote:

Macro guy wrote:

...............

However, most lenses for non-view cameras are not symmetrical. Therefore, whenever you reverse mount a lens, you get somthing called lens reversal extension and that affects your magnification. The reversal extension is dependent on the optical formula of the lens, so it will be different for every lens.

Interesting.

Hence the disparity between what BBbuilder467 was experiencing vs. what I was. Also between the two 50mm Nikkor lenses (1.2 vs. 1.8) on the Nikon spec sheet.

You have to account for that with cameras that have no through the lens metering systems, however, since all digital cameras have a built in meter, the reverse extenstion factor is irrelevant.

I guess what's relevant is the lens you choose, plus the camera you're using it on.

Since Nikon has such a steeped history in MF glass, that is so easily-mounted on virtually anything, most people choose to reverse-mount Nikkor AI/AI-S glass to their cameras, regardless of their preferred camera system.

At the end of the day, they can verify everything simply by viewing Nikon's own sheet, then taking a photograph of a mm ruler, in measuring "the amount of mm" framed by that optic.

In my original post on this thread, the Zoom Nikkor I suggested had the greatest versatility, whereas when using a prime, you're pretty much stuck at that focal length/magnification.

I prefer mounting the reversed lens on a bellows.  I find that type of a setup gives me the greatest flexibility.  I can change my magnification with a given lens (within that lens' focal length parameters) and I can focus without changing my magnification.

Here's what my setup looks like.  It's not the greatest pic, I took it with my phone, but you get the gist.