I have an old light meter I haven't had much occasion to use... but now I'll need to make sure it's reliable - I'm going on a month-long trip to Puerto Rico and lots of my photography will be done using a Yashica-Mat and my Pentax 645N. I use 6x7 lenses on the latter and the camera's built-in meter is often totally off when I stop those down. The former doesn't have a built-in meter.
The meter is called Sekonic Auto-Lumi, like the one here:
How can I double check it's metering fine? Forgive if it's a dumb question - If I were to use this meter's readings on my Pentax K-x DSLR and the exposure seemed correct, would it still be correct for my film cameras?
PS The only time I did use it, for one roll on my Edixa Reflex, it seemed to underexpose somewhat. Here are some drugstore scans from that roll:
Flickr: Search dubesor's photostream