Originally posted by Na Horuk I don't think what you are asking is possible.
You can also meter by pressing the +/- button, I think.
Your first statement is, as far as I've been able to determine, correct. I just tried using the +/- button, and it does not stop down a manual lens to take a meter reading.
With some Pentax DSLR models, where the DOF preview is available as a 3rd position for the on/off switch, the meter is active during DOF preview, allowing you to scan and meter various parts of a scene. Very useful if you have spot metering enabled.
The K30 does not offer DOF preview in this way. You can configure the Fx button to be a DOF preview button. Unfortunately, when you activate DOF preview using this button, the meter is not enabled. So a handy feature of my old K200D isn't supported by my brand new K30.
This has been discussed several times in the K30/K50 section of the forum.