Mon Aug 27 09:58:53 EDT 2007 William Robb wrote:
> ----- Original Message ----- > > From: "David J Brooks" > Subject: Re: Wedding photography > > > > I have proven to my self over an over, if i'm going to do indoor > > flash, the SB80DX and D2H are the only way to go for me. More > > consistant results. > > > > Sorry Pentax wedding folk.:-) > > I've had no luck at all with Pentax's flash control over the years. From the > LX and it's refusal to fire the flash in fill situations to the istD and > it's really bad TTL control to the K10 and it's klunker flash interface, > I've just never liked using pentax camera controlled flash. > I think the people who are happy with it have never used a good flash > control system such as Nikon's. > I liked the combination of ZX-5n+AF500FTZ in TTL mode. Not a perfect combination but good enough. I never had that much experience with the automated flash control system of Nikons. If my understanding of how the TTL metering works is correct, I suspect that the DSLR introduced a new, almost "fundamental" (although, probably technologically solvable) problem: due to the highly reflective sensors, the measurement of the much higher intensity reflection during the flash burst : a) requires a higher dynamic range meter, and b) depends more on the exact way the light bounces back from the object and from the sensor, -I think they do some sort of extrapolation in the electronics - to estimate when the flash needs to be turned off. Thus, TTL metering in DSLRs is less accurate. That's why, I suppose, they have to come up with more complicated ways, like P-TTL. I wonder though, why the metering is still done via reflection from the sensor (is that the case?), and not by including some exposure metering sensors on the sensor chip? Or am I wrong and it is already implemented? For those (like me) who is interested to understand how various *TTL metering schemes work the following pages may be helpful: General ideas (and Nikons specifics at the end): http://www.moosepeterson.com/techtips/flash.html Nikon: http://www.planetneil.com/nikon/flash.html Canon: http://www.bobatkins.com/photography/eosfaq/flashfaq.htm Comparative table for various systems: http://www.photozone.de/3Technology/flashtec6.htm I didn't find a comprehensive page for Pentax flash system (but I was not looking hard for it, as they were more clear to me). Igor -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
