Originally posted by RiceHigh Or +0.7EV??
We should still start from the assumption that K-7 matrix mode needs no EV compensation, even for your needs.
As far as center-weighted mode is concerned. You may make the following experiment:
If you have a Pro-level Canon and a Pentax, they both should meter identical in spot mode (for a grey color uniform surface). At least, they should do so.
Now, my K20D meters exactly identical in spot, center-weighted and matrix mode (for a grey color uniform surface). Now, as there is no norm for this, other vendors may meter brighter in center-weighted and matrix modes.
So, you may want to meter a grey color uniform surface in spot and center-weighted modes with your Canon and note the EV difference in exposure readings. On the Pentax, use this value as EV compensation in center-weighted mode and both brands should give you identical results in center-weighted mode. As I said, it is an arbitrary choice, anyway.
In matrix mode, things may be trickier. Actually, to expose a uniform surface as it would be 18% grey in matrix mode is a bit disappointing. Matrix metering should be able to detect that a surface is uniform and therefore, expose brighter. Here, I am with you, RH. But if they changed that for the K-m, than probably for the K-7 as well