I've played a bit with trying to compare guide numbers
In a darkish room I set up my DSLR (28mm equv WA) on manual mode and a farly high F, i.e. 10-14 and fired the flashes from the same distance at full power against the wall, and adjusted F until i got about the same histogram on all.
Yongnou 462 F13
Yongnou 460 F14
YS110 F10
(i.e. not quite a full stop spread, right?)
On paper the YS110 has GN22, Y460 and Y462 has GN32
So, I suppose the crux now is the angle, the YS100 is 105degrees circular, while i dont know what the Chinese flashes are specified for, but i strongly suspect that the 462 that has zoom is specified at maximum zoom (smallest spread) and the 460 for at most maybe a 28mm equiv (about 75 degrees).
Am i right to assume that this indicates that the Yongnous are probably very optimistic in their guide numbers? How useful would these ordinary yongnou flashes be as auxilary UW strobes with slave triggers? They are dirt cheap, and I can easily get a housing that they will fit.
Cheers
/O
