Can anyone tell me how bright these flashes are, or where I can find information telling me what illuminance they produce (fc or lux is fine, or f-stops) ?
rg2 On 8/28/07, Adam Maas <[EMAIL PROTECTED]> wrote: > William Robb wrote: > > ----- Original Message ----- > > From: "Toralf Lund" > > Subject: Re: TTL, P-TTL, other *TTL's and DSLRs (Was: Wedding photography) > > > > > > > >> Something I've been wondering about lately, is which is better of a > >> traditional auto-mode and P-TTL. I mean, which is greater of the error > >> in the pre-flash based prediction and the inaccuracy resulting from > >> using a sensor not measuring through the actual lens (and making > >> calculations based on a "theoretical" aperture)? Any thoughts? > >> > >> Maybe the best result might be achieved if you used an external sensor > >> to control the actual flash operation, but included a through-the-lens > >> pre-flash measurement to collect knowledge about the actual exposure > >> conditions? Is anyone doing that? > > > > Once I left Nikon, I discovered that basic auto flash was more accurate than > > TTL flash. I happen to have a very accurate auto flash though, I expect a > > cheap auto flash will be as inaccurate as the rather useless Pentax in body > > flash control. > > I suspect that the best way to get body controlled flash would be to > > transmit distance information from the lens rather than use reflective > > information from the sensor. > > > > William Robb > > > > > > Which is how Canon E-TTL II works(E-TTL primarily used reflectivity under the > selected AF point), and is also used by P-TTL and Nikon's D-TTL and i-TTL > systems. > > -Adam > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
