Actually I'd also like to know since when bounced or using the omni bounce cover it still exposes correctly even with 2 stops loss. It seems that it does it something more like this ( using your theory as a template )
- lens says it's focused at 10 feet - flash guide number is 40 - aperture is f/2 Fire the flash at 1/2 power but meter just in case. --- tom <[EMAIL PROTECTED]> wrote: > I've noticed over the course of the last year that > rolls of film that were shot with TTL flash metering > (and flash) have much more consistent exposure > across frames than rolls > that used matrix metering and ambient light. > > I've come to this conclusion after proofing dozens > of rolls of b+w. > > Seems to me the only way to explain the difference > is that the flash output is determined by distance > info transmitted by an FA lens. > > I'm not really sure what that implies...I was under > the impression that TTL flash metering worked like > so: > > - flash starts to discharge > - ttl flash meter measures output > - ttl flash meter determines that subject has > received enough light > - meter tells flash to stop > > However, if it's using distance info it's just using > a calculation. > > - lens says it's focused at 10 feet > - flash guide number is 40 > - aperture is f/2 > > Fire the flash at 1/2 power and don't bother > metering. > > Maybe it (I guess I'm talking pz-1p here) uses that > calculation with FA lenses and uses quench metering > with older lenses? > > I might have to test this.... > > Thinking out loud, > > tv > - > This message is from the Pentax-Discuss Mail List. > To unsubscribe, > go to http://www.pdml.net and follow the directions. > Don't forget to > visit the Pentax Users' Gallery at > http://pug.komkon.org . > ______________________________________________________________________ Find, Connect, Date! http://personals.yahoo.ca - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
