DP-2 Gone Bonker, or What?

I’m facing an extremely perplexing metering problem with a recently acquired F2S (DP-2 prism).

 

A couple of test rolls of Kodak Elite 100 slide film came out grossly overexposed. Well, I though, either the meter

needs to be recalibrated, or the shutter must be adjusted. So I proceeded to start by testing the former.

 

An uniform matt white target (one of my wife’s painting canvas) produced a reading of f5.6 at 1/250 (100 ASA) in my

LunaPro (with correct voltage batteries), which was confirmed by another camera of known accuracy (Minolta XD-7).

The F2S with the same lens I used for the test rolls ( a Soligor 28-70mm 3.5-5.6 zoom) returned a reading of f5.6 at

1/30, which of course explains the overexposure. A clear case of the meter needing major recalibration, or so it

seemed. But wait.

 

I proceeded to test the F2S again with the 1.4 50mm lens, and lo and behold the reading was f5.6 at 1/250. I then

went on testing several other lenses, with very interesting results: the 85mm 1.8 says f5.6 at 1/125, the 24mm 2.8

says f5.6 at 1/60, and another 3.5 lens confirms the Soligor zoom at f5.6 at 1/30.

 

In other words, the meter seems to produce readings that depends on the maximum aperture of the lens mounted

on the camera, which is pretty weird. And, yes, I know about the “Nikon twist”. Has anyone experienced a similar

problem? Can anyone guess whether the cause lies somewhere in the meter, or rather in the connection between

the body, the lenses and the meter?

It sounds like the maximum aperture indexing mechanism in the head isn't working properly. The f/1.4 that gave the correct reading is close to the maximum f/1.2 that the head can manage which tends to support this theory.

 

If it's not a silly question did you confirm that in each case the lens maximum aperture was indicated in the little window on the head after you'd done the "Nikon twist"?

 

You could try using the head in stop down metering mode to narrow down the area of trouble. I believe you push the little pin up into the head after setting it to f/5.6.

This is a question for <a href="http://www.geocities.com/sover_wong/Nikon_F2_Repair_Service.html">Sover Wong</a>, Nikon F2 specialist extraordinaire.

Sover is the man when it come to F2 bodies. I gave him one of the F2AS bodies a couple of years ago and he brought it back to complete factory specs like it was brand new. He's in England but ships back and forth internationally. Has all the right tools for the F2 and the knowledge -- this is the only camera he works on.