PQS lens aperture wrong in finder

<p>I received a used lens today, the manual focus 4/120mm Makro-Planar PQS. <br>

Went out today and found that with aperture selection the times were all wrong (far too long). Then I discovered that the aperture displayed in the finder was wrong: only 8 and 11 would be correct, all others would display 32. And at 32 it would have the wrong speed.<br>

At home I checked whether the lens closed down properly via DOF preview. As far as I can see all apertures close down correctly from 4 to 32.<br>

I cleaned the contacts. Now the only aperture displayed is 32.<br>

If the lens is set to A it does seem to get things right, however.<br>

Any thoughts? I noticed a related question, <a href="/medium-format-photography-forum/00LAxl">with 2.8 on a Planar PQ lens</a>, but the OP did not post whether he resolved the issue or not. Also, if a service is needed, I would have to get one in the UK. If not too expensive, I'd do it as I got the lens very cheaply. But if it is proving costly, I might have to send it back, which I do not want.</p>

<p>The electrical portion of the lens is what is at fault. Check the contacts on the lens and verify that they are all clean and at the same height. If they are good then have the lens serviced. The possibilities are the sensor inside the lens is bad, a connector lead to it is broken, or the A/M switch is bad.</p>

<p>Thanks for your reply. I checked the contacts and cannot see anything wrong, cleaned them with a tip.<br>

So a service must be. Since the lens at A does use all apertures correctly, would that not imply that the sensor is OK?<br>

I do wonder about costing in the UK but have sent a few emails out. </p>

<p>send back to DHW. Not pricey, fast, and they do know what they are doing. </p>

<p>Geoff, I've done just that, although I don't know yet the price (asked for a quote). But indeed, they have the experience and the parts. Thanks for sharing your thoughts</p>

<p>Harry,<br>

I have a Schneider 180mm 2.8 lens that had the same problem. The aperture manual selected settings were off. F/4 set on the lens aperture ring would read 2.8 in the viewfinder. <br>

I sent the lens to Danielle Inc. in New Jersey and they replaced the aperture ring switch connector, and it cost me $278.00, parts and labor. This was of course about four years ago, so I would imagine that it might cost a bit more today. </p>

 

<p>I would have said to send this in as well, so glad you have already done so. There can be a number of faults that can cause these symptoms. DHW provides fast and competent service. Hopefully its just a resistor board, but can also be a shutter going out (don't ask me how I know) :-)</p>

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