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  1. #11

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    Thanks again for all of the replies. Judging by your comments my meter needle placement might be within the normal range. I also have an SPF that I am planning to send to Eric Hendrickson next week, so I was getting opinions here about the SPII meter so that I could send them along with the SPF if they were behaving abnormally compared to everyone else's. I'm doubting my theory about the meter needle now, however the settings definitely do seem to be a stop or two out so maybe there's another reason. I think I'll send them along to Eric with the SPF anyway and get him to either calibrate/fix them or give me peace of mind that nothing is wrong.

  2. #12

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    I have several SP II's and 2 SP's. In all of them the needle is below the centre when the meter is off but not totally down like with severe underexposure. When the meter is switched off the needle is mechanically fixed at this rest point to prevent it from swinging caused by movements of the camera. There was only a change in the needle rest position during the early series of the SP in the sixties.
    If your measurement result is different between 2 bodies and against an external meter or another camera the reason could be ageing of the CdS cell. But Asahi used very stable cells, all of my cameras are o.k. A Practica MTL 5 (from about 1983) which I bought for 5 € has a deviation of -2 EV-stops, this seems to be very common for aged CdS cells from East Germany. The meter can be adjusted to a certain extend by a service technician or by a skilled amateur, you can find the service manual for the Spottie in the net. I hope you will have a lot of fun with these cameras and their beautiful lenses.

  3. #13
    Steve Smith's Avatar
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    Copied from a post I made on Photo net earlier:

    I have checked my four Spotmatics and the meter needle on all of them rests just below the zero position. A bit of research has shown that the Spotmatic circuit actually applies a very small offset current through the meter at correct exposure so my comment about zero current flow at correct exposure was not fully correct (although it's such a small amount that the principle is still the same).

    I found this:

    However, the Spotmatic circuit is offset slightly so the correct exposure reading is slightly off of centre with a small amount of current flow. This was done (I think) to enable the battery check function to work).

    What this means is that the Spotmatic circuit is slightly voltage dependent but not by enough to worry about in normal use.

    The embarrassing thing is that I wrote it myself about three years ago!

  4. #14

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    Thanks again to everyone who is taking the time to give their insights here.

    Quote Originally Posted by jochen View Post
    I have several SP II's and 2 SP's. In all of them the needle is below the centre when the meter is off but not totally down like with severe underexposure. When the meter is switched off the needle is mechanically fixed at this rest point to prevent it from swinging caused by movements of the camera. There was only a change in the needle rest position during the early series of the SP in the sixties.
    That last sentence might be the missing piece of the puzzle regarding what I thought should be the needle's normal resting place. The "Pentax Way" book I've been reading is a first-edition from 1966. Could it be that the rest position changed from dead centre to down a little in the underexposure region after that book was released?

  5. #15

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    Hello,
    the Spotmatic was presented on the Cologne Photokina in autumn 1964 and first sold late in 1964. If your book edition is of 1966, maybe the early series are meant. On weekend I will look into my Pentax book whether I can find something about the early rest position of the needle.

  6. #16
    Ricardo Miranda's Avatar
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    Hi!
    That is true, several modifications were made to the Spotmatic during its run.
    The original Spotmatic had the needle resting on the centre and the needle was also smaller. The switch was also much narrower and with a small round window. That was changed to a larger switch without a window. Asahi was always improving the model!
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  7. #17
    Bill Burk's Avatar
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    Quote Originally Posted by Steve Smith View Post
    A bit of research has shown that the Spotmatic circuit actually applies a very small offset current through the meter at correct exposure.
    Quote Originally Posted by jochen View Post
    When the meter is switched off the needle is mechanically fixed at this rest point to prevent it from swinging caused by movements of the camera. There was only a change in the needle rest position during the early series of the SP in the sixties.
    It all adds up. They did it on purpose. And I know why they did it! It's so obvious. Asahi engineers realized with the normal rest at perfect exposure there would be many mistakes of shots taken with the meter off. When you know you have to put the needle in the middle... It doesn't take long to realize the meter is switched off when the needle doesn't move in response to shutter speed - f/stop changes.

    Now I have to rationalize why it changed with the F, back to rest at the middle. I could give the engineers credit that they knew users literally could not forget to switch it on. Or I could anthropormorhize them (ascribe normal human traits) and assume they forgot about the previous improvement.

  8. #18

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    here the information from "Gerjan van Oosten, The Ultimate Asahi Pentax Screwmount Guide, 1999", page 58: ".....Resting position of the light meter needle improved since June 1966 (points to the "-"-sign...."

  9. #19

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    Thanks Ricardo and Jochen. Mystery solved :-)

    I had been planning to send an SPF and some Takumar lenses to Eric Hendrickson, which I did today, so I sent the SPII bodies along for the ride too with a request that Eric check the meters and recalibrate them if necessary.

  10. #20
    Hatchetman's Avatar
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    Just FYI, he sends you an "invoice" which is really just an estimate for work pending. I thought he was done with the work. I called a few weeks later wondering where the camera was. He said he hadn't started working on it yet. But he got to it shortly and the work he did on a moldy lens was amazing.

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