Spotmatic F meter question

<p>I recently acquired a Pentax Spotmatic F which is in good shape. Only (minor) problem is that the mirror does not always return properly when using slow speeds since the second curtain sometimes does not travel all the way - pushing the second curtain to its final position usually helps.<br>

The lightmeter is approx. 1 stop off but this is not really annoying since the ASA dial goes up to 1600. But there is a strange issue with the light meter. Even if the light meter is switched off (button at the lower position), the needle shows some reaction to light (of course the needle position changes drastically), it is moved when turning the speed dial and also moves in bright light conditions. Is this normal?</p>

<p>The meter in the Spotmatic F is only "off" when the lenscap is in place, thus no light reaches it. So yes, it's normal. It's just the way they were designed.</p>

<p>Although the switch on the left side of the lens mount appears identical to the original Spotmatic and SP II, its functioning is reduced. On those earlier models, pushing up the switch served two functions: (1) to close the lens diaphragm for "stop-down" metering, and (2) to turn on the meter.</p>

<p>Because the Spotmatic F has "open aperture" metering, its meter must be on even when the diaphragm is not stopped down. So, pushing up the switch on the Spotmatic F serves only one function: to stop down the diaphragm for depth-of-field preview, if desired. The Spotmatic F has no switch to turn off the meter--only the lenscap will do that.</p>