Gosh. What's the point in even buying one of these things if you're just going to wing it? Properly
calibrated, a Pentax spotmeter is going to be invaluable for all kinds of exposure situations, esp when
working with LF films. But I use one in preference to thru-the-lens small camera meters to - once you get the hang of it, it will be more accurate evaluating lighting ratios, and makes Zone System work a piece of cake with any camera, if that's what's in mind. Locate someone else who has an
accurate meter of the same species and compare them, then in necessary have it calibrated. But
don't guess or try to guess what some other kind of instrument is thinking!