Adapters for old gear

IPLRS_2

Hi All,

I love my old gear but have finally decided to make the change.

I have been using the same Asahi Pentax Spotmatic ever since I bought it new in Hong Kong in 1968. It still works fine. Had the shutter speed tested a short while ago and it is still within tolerances. Originally, I bought a full set of three lenses (all screw-in, of course), filters, and extension tubes. We/I still use them all.

We have decided to go digital and have bought a current Nikon D3200. Of course it uses a twist-lock mounting system. I've purchased two different adapters over the web, and neither works.

Anybody have thoughts on where I should look online? We shop EBay a lot.

Thanks for any help,

IPLRS_2

bruto

First of all, "work" is relative here. All Nikons since the first F have used a greater lens to focal plane distance than all other SLR's, and for this reason you cannot adapt any non Nikon lens to full function on a Nikon unless the adapter has an added glass element to compensate. All other attempts to adapt will result in loss of infinity focus, as the lens will be too far from the sensor. You can set up some neat macro rigs, but normal use is out.

Be aware that the Pentax screw thread, while the same diameter as a T mount, is not the same pitch. A T mount adapter will not thread on properly and will not push in the aperture pin properly.

The automatic aperture mechanism on a Pentax screw mount is opposite that on most others. If you hold an old Nikon (or Minolta, Konica, etc.) lens in your hand, and operate the aperture, it will, by default, work. The camera mechanism holds it open while you view, and it's manual off the camera. On a Pentax lens, if you hold it in your hand, the aperture will remain wide open. The camera mechanism holds it shut. For this reason you must have a proper Pentax adapter that engages the rear pin or the aperture will remain wide open at all settings.

The D3200 will mount almost any Nikon F mount lens, but will not meter with any but AF lenses with electronics. It will not autofocus with any but internal motor lenses and will not operate the automatic diaphragm correctly on any lens except Nikon F. I regularly use old F lenses with mine, metering with the histogram, and results are very good. Some of those old lenses are very good indeed, but stick with Nikon unless you're a macro gadgeteer.

Fine as those old Pentax lenses likely are, it's quite possible the cheap kit lens on your D3200 is just as sharp or sharper. The price of retrofitting the Pentax stuff is likely to be high compared to getting the right stuff for what you have. Keep it together, and keep using it, but I would not bother to convert.

IPLRS_2

Thank you. Not what we wanted to hear, but we will follow your advice.

PaulsPics

I went through all of this when I bought my D3200, my first DSLR. I had (still have in fact) Olympus 35mm gear and wanted to convert one or two lenses to use with the Nikon. After much searching, I came to the conclusion that it's not worth it. If you want to get the very best out of the D3200, buy good quality lenses. They will outlast the camera body, and also will not compromise it's performance.
However, what you can do is buy a reversing ring with a Nikon mount so that you can reverse mount a Pentax lens for macro photography. The ring screws onto the front of the lens, then mounts onto the camera. I have one for my Olympus OM 50mm f/1.8 lens and one for my 35mm f/2.0 lens. It's a simple and inexpensive way to give your old lenses a new lease on life.

bruto

Reversing a normal lens can give you very fine macro performance. Finicky for focus and distance, but very close and very sharp. Just remember though that the Pentax screw type mount is unique in that you will have to tape down the aperture pin or the aperture ring will not operate the aperture. It will remain wide open.