asking flash distance in GN Mode...

[encikboyak]

hi...
i m aware about the GN calculation...for optimum result...

GN = Aperture x Distance

and the distance mean 'from camera to subject'
but...are this apply to the distance from the flash to subject...
(situation - subject in 12 o'clock)
(situation - flash in 6 o'clock / 45deg toward subject)
(situation - flash in 9 o'clock)
(situation - reflector in 2 o'clock)
hope this will help..

thank in advance

 

[Youhong]

Hope the following will help
http://en.wikipedia.org/wiki/Guide_number

 

[giantcanopy]

hi...
i m aware about the GN calculation...for optimum result...

GN = Aperture x Distance

and the distance mean 'from camera to subject'
but...are this apply to the distance from the flash to subject...
(situation - subject in 12 o'clock)
(situation - flash in 6 o'clock / 45deg toward subject)
(situation - flash in 9 o'clock)
(situation - reflector in 2 o'clock)
hope this will help..

thank in advance

It should be distance from flash to subject
U can take it as from the camera to subject since the difference issin that great unless u are using it off shoe.

Since it is a function of the distance of the light from the flash travelling to the subject u need to look at the path taken

E.g if u r bouncing flash off a wall to the person, the distance will logically be longer compared to a directed flash

Ryan