Originally posted by SOldBear It depends....
I think the GN of the 283 is 120 (ft, ISO 100).
In direct sunlight, a proper exposure at ISO 100 is F/16 at 1/125 sec, or F/13 at 1/180 sec.
Let's use 1/180 sec. max sync. speed.
For the 283, at F/13 and ISO 100, the distance is 120/13 = 9 ft. That is for lighting ratio 1:1.
If you want ratio 1:2 (flash is for fill-in, 1/2 strength of sunlight), the distance is 9 * 1.4 = 12.6 ft.
If you add the softbox, which eats up light from the 283, the distance is much less than calculated above. If the softbox eats up 2 stops, you'll have to halve the distance (e.g. 4.5 ft for 1:1 lighting ratio).
that is great information and thank you!
sounds like it might be o.k on an overcast day, hopefully the wedding coming up will be that way,,,
btw, if I could find a way of using 2 283's in the softbox, would that double the distance or would I be able to use 2 at 1/2 power to equal one at full power so it will recycle faster?
thanks again