----- Original Message ----- From: Artur Led�chowski Subject: Lighting advise needed
> My questions are: > - how big is the light loss due to bouncing the light off the umbrella? how > much more should I open the aperture - 1/2 stop. 1 stop, more? Measure the distace from the flash to the center of the umbrella and back to the model for flash to subject distance. Every umbrella that I have seen is 50% efficient, so the umbrella will eat a stop. FWIW, I have better luck using umbrellas as a shoot through, not as a shoot into, meaning the umbrella is between the flash and the subject. > - how can the flash from the AF500FTZ affect the camera TTL-flash metering > of the burst from the Sunpack? I presume that it may fool the camera making > it underexpose its metering but I want the Pentax flash to be the key light > and the Sunpack to fill the shadows and maybe bounce a little of light off > the ceiling onto the models hair... Not a clue. I would expect it will cause the camera to shut down the on camera flash early. You could use this to advantage by using exposure compensation to dial in the amount of fill you want. William Robb
