konica auto S2 meter

[fstop]

Hello (first post!)

I acquired a Konica Auto S2 for a few quarters a few days ago. It arrived with its shutter jammed and the winding lever locking washer all forced awry. Fixed these one way or the other, shutter was the most work.

Now all I want to do is to tweak the meter, it is over-exposing by a few stops (using ASA dial for exposure compensation won't work here, the offset is too large for a 200 ASA film). I am using the hearing aid battery #675 and its voltage in the camera is around 1.4 V. Looks like the CdS sensor has aged, since a voltage higher than the desired 1.3V should be *under*exposing.

Anyone know how to reach the meter setting? It looks like there is a potentiometer on the left side of the meter, just by the rangefinder, and this might just do the trick ... if only I can turn it somehow.

Thanks!

[Julio1fer]

Usually with higher voltage you get higher current = more light metered than actual, therefore underexposure exactly as you state, but it depends on the circuit. You should be able to adjust the meter for higher voltage, but I don't know how to do it in a Konica S2. The potentiometer is a good bet if you can point the meter to a reproducible illuminated subject and compare readings with a known good meter. Mark the original position, no harm is done if you return it to where it was. 

If you'd rather don't mess, you should actually do fine just setting one or two stops down in the ASA dial. Run a test roll with different settings and calibrate ISO according to results?

[sandeha]

That's what I did with mine.  Using a 625A, 1.5v battery just set the ASA one stop lower.  With 400 film at 200 it was spot on.  Helluva nice lens.

[fstop]

Yes, adjusting the ASA was going to be best option. However, as I mentioned earlier, the error is too large for this. I have a bunch of 200 ASA films to try, but I can't set it beyond 400 on the camera.

Last night I took off the frame counter, then the little black slit through which the meter scale is visible in the viewfinder (had to remove two screws and carefully removed the slit using a pair of tweezers while keeping the mirror clear of the meter needle) and then the plastic cover. This gave better view the meter. I could see the variable resistor clearly, but it is difficult to reach with the rangefinder in place.

[sandeha]

There's Scott's thread here that discusses a few metering issues ... http://nelsonfoto.com/SMF/index.php/topic,6841.0.html

It might be that adjusting the meter mask in the front of the lens would be a more simple option.  Dunno, I'm just guessing.

With 200 film I'd set it to 100, though I agree that the range of possible films is limited.

[fstop]

Setting to 100 for ASA 200 film would overexpose even more! I suppose you meant to write to set it to 400.

Yes, I went through that thread last night. Quite informative thread, with all the pictures and legends in them. Nice work by Scott!

I wonder if anybody has pictures how to remove the meter altogether. I was almost going to do it last night, but I wasn't sure I recalled all the linkages underneath. I will probably look further into this option. I am suspecting that the meter unit should be come right off after removing its two or three screws that secure it to the body. The two wires (green and back from the battery compartment) need to be desoldered though. I haven't been able to find any photos on the web showing this procedure yet.

Thanks.

[sandeha]

Ah, sorry. I missed something in reading your first post - your overexposure. 

Mine was underexposing purely on account of the higher voltage battery, hence my solution for my problem. 

[fstop]

I have been thinking about the battery factor as well. At present I am using the hearing aid battery #675 which is giving me a voltage between 1.35 and 1.4 V. Perhaps I should try another battery which is reported to give 1.55 V. I think it is some kind of alkaline, but am not sure about the number. That would help in bringing down the over-exposure.