My camera is a Nikon D70
2006-12-30 21:48:17 · 3 answers · asked by Anonymous in Consumer Electronics ➔ Cameras
You would only need to do guide number calculations if you are using an old, non-automatic flash, or if you are just a rugged individualist who insists on doing things the old-fashioned way.
But...
Guide numbers (GN) must be expressed relative to ISO and you have to know if it is expressed in terms of feet or meters. I will assume "feet" in this example, as that is what I always knew.
[f-stop = GN/distance] is the formula.
If you have a Guide Number of 120 for ISO 200 and the subject is 12 feet away:
f-stop = GN 120 divided by 12 feet = f/10 at ISO 200.
Where is f/10? It's about 1/3 stop below f/11 or 2/3 above f/8 or "close enough is close enough," as we say.
2006-12-31 05:19:30 · answer #1 · answered by Jess 5 · 0⤊ 0⤋
its all based on a sequential scale. and why are you calculating flash exposure... the Nikon does it for you, unless youre on manual. in which case buy a flashmeter. and if you load the CD that came with the camera, it'll explain it.
2006-12-31 06:10:49 · answer #2 · answered by Anonymous · 0⤊ 0⤋
if you go to http://www.dcmag.co.uk/Flash_exposure.Yae4Djto39cnPg.html this should help explain it for you or http://photonotes.org/articles/eos-flash/index2.html this should also be of help to you
2006-12-31 06:30:41 · answer #3 · answered by Anonymous · 1⤊ 0⤋