[Ian Grant]

In other words, on a Super Takumar lens or Takumar lens, there is a connection with the meter switch and the meter electronics on a Spotmatic F. Soon as you put an SMCT lens on, the meter switch is disconnected and the meter is always on.

That's a bit confused

There's a lug on the SMC Takumar lens that turns the meter on, however it does not de-activate the stop down metering switch which if used then gives false readings. So just trying it with a correct reading of a 30th @f5.6 when the stop down switch is used it claim itneeds a 30th @ f11 (both with SMC Takumar lens).

I had great difficulty persuading my wife not to use the meter switch on her K mount Pentax with its standard lens, this gave similar false readings.

Ian