In article <44bm1k$7lk@newsbf02.news.aol.com>, richcasale@aol.com says...
>How do I calibrate my camera's ttl meter?

Without a good reference meter, it isn't easy. You can begin by
exposing a low-latitude slide film (actually, all slide films are low-latitude, but some are even lower than others) like Kodachrome
64 (which is accurately rated IM(NS)HO relative to most other slide
films) in varying lighting levels. Try to keep the lighting uncomplicated, so accurate metering is easy. Try also to keep the subjects neutral in color (meters read saturated colors very inaccurately). Expose frames at -2/3, -1/3, 0, +1/3, +2/3 stops from
the indicated readings in the camera. Keep careful notes. Have the
film processed by a reliable lab to reduce that variable. If all goes well, all the exposures at one of the ratings will be correct. If not, and the exposures vary (no one exposure set seems to be correct), the meter is probably non-linear, and would need repair. If not, but the exposures are consistent (say, a hair light at -1/3, but a hair dark at 0), you can either live with the slight error and choose the preferable error for you, or have the meter adjusted slightly (difficult, unless you can do it yourself). If one of the sets is consistently correct, adjust the ASA rating to give you correct exposures (i.e., if the -1/3 stop frames were correct, increase the ASA rating 1/3 stop to 80, and set that on the camera when using ASA 64 film - and adjust other ASA film ratings likewise).
Hope this helps.