Todd wrote:
> Based on the above and the SB-28 manual, Thierry did some
> postulating about flash duration.
>
> Thierry's theory looks like it's mixing high speed sync (or FP)
> tables in with conventional flash, and I think that's not a valid
> comparison.
It could be not, I agree. I was just trying to understand and link data
together.
> The original poster's info (1/150 second) is probably good for
> SOME flashes, but not the ones I commonly use. The SB-26 has a
> max duration of 1/1000 sec. and min duration of 1/23,000 sec. The
> SB-28 has a max duration of 1/830 sec. and min duration of 1/8,700
> sec. (These figures are from Thom Hogan's most excellent "The
> Nikon Field Guide").
Assuming Todd is right, why does the SB-28 guide number fall down when
synchro speed gets quicker (at least up to 1/830s)?
> To get to Thierry's basketball question, the SB-28 flash output is
> always going to be faster than 1/830 (or faster than the 1/500 he
> required), so the flash will freeze the action. The trickier
> question is whether there will be enough ambient light to render
> the basketball player as a blur. Lighting will vary from court to
> court, but using the max (conventional) sync of 1/250 should
> minimize any ambient blur.
This is a point I haven't thought about. I'm not used to high speed synchro
yet and don't think of it when I could need it.
Thanks for your answer, Todd. And by the way, I'm going to have a look at
my local library if they have got Thom Hogan's book.
Thierry
