Any input would be appreciated. I have a stable of TTL-capable Sunpak flash units I've used successfully with a Contax 645 shooting film, using the appropriate dedicated TTL module for the C645.
I've been shooting mostly digital for about the past five months since picking up a Kodak ProBack for this camera, but until the past few days I've used very little flash with the camera and digiback--and then it was either studio flash triggered with PW's, or the shoe/handle units in "manual" mode. No problems used this way.
Rainy weekend so I've been experimenting with TTL flash and find I'm getting wildly inaccurate flash exposures. The same flash units give pretty good exposure when using various "auto" modes relying on the flash units' own exposure-determining capabilities; or when I set flash power manually and meter with a flashmeter or with the Contax's own flashmeter capability.
I've not been able to find this clearly stated out there anywhere, but I'm guessing this is due to the fact that TTL measurements are made off the film plane; and if film is replaced by a digital sensor, the reflectivity of which differs markedly from that of film, then TTL exposures are going to be off by quite a bit. Am I warm here or way off base?
Are there any TTL capable flash units (eg Quantum) that you folks have used with digibacks with success, specifically with the Contax 645 and ProBack?
Ironically I rarely use TTL flash capability, but now I'm curious to solve this "mystery"! thanks in advance!
