From: Henry Posner/B&H Photo-Video <[EMAIL PROTECTED]> Re: Nikon vs. Canon FP flash mode (was:) Flash sync speed - how important is it? >From Thom Hogan's post, as quoted by Henry Posner: >The poster at www.chemlhelsinki.fi must be a Canon user. The statement >"therefore a part of the flash energy is wasted" doesn't apply to the Nikon >FP mode. Using the terminology that we on this list are familiar with, of course it does. The only way to have FP is to illuminate the curtain, which, depending on the shutter speed, may be a very large percentage of the focal plane. Of course, the higher the shutter speed above the shutter's natural X-sync speed, the smaller the area of film that gets painted at a time, and thus the reduction in effective GN. Same thing that happens with the old FP flashbulbs. >Yes, the Nikon FP mode is a manual flash mode, and to use it effectively you >sometimes have to iterate settings (on my flash instruction cards I note in >Step 6 "you may find that you have to go back to Step 4 and iterate until >all the settings match up." Whatta UHPITA (Unholy Pain In The Aft). >The first payback is that the entire power of >the flash is released across the full set of pulses during the shutter >cycle, maximizing GN. Which Canon's E-TTL under FP mode will give you, automatically, when it thinks the exposure will need it. >The second payback is that you have control over the >frequency and number of flashes during the cycle. Really careful >photographers shooting certain kinds of motion sequences can use this >to do >interesting things, such as calculate the actual speed of an object in a >scene (imagine someone doing golf swing analysis, for instance--by >starting >the shot at the top of the swing they could probably calculate club head >acceleration and impact speed--of course, these days they do that kind of >analysis with video, but if you need the resolution, the Nikon FP mode is >pretty useful). Great feature. But it's not FP flash. It's what we Canon users know-and-love as "Multi-flash." DGW * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
