Re: [Leica] OT Flash guide numbers and they work? OT

["Mark Davison" <DAVISON_M@msn.com>]

In a nutshell:

Guide Number / Distance to subject = f-stop.

So for example,

if the guide number is 20 meters

the distance to the subject is 10 meters

then the appropriate f-stop is 20 meters / 10 meters = f 2.0


The f-stop alone controls the flash exposure, you control the contribution
of the ambient light with the shutter speed, remembering to keep it at or
below the synch speed.

Mark Davison




- ----- Original Message -----
From: "Ted Grant" <tedgrant@shaw.ca>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Friday, July 12, 2002 3:23 PM
Subject: [Leica] OT Flash guide numbers and they work? OT


> Hi folks,
>
> This is right off the wall ancient need to learn it over again.
>
> A chap down the street called and asked me how to use the guide number on
> the flash he has?
>
> Well OK I thought I knew.... however that was 45 years ago when the flash
of
> the day had guide numbers. Even then I had trouble figuring that stuff
out,
> then I discovered photo life was much easier when you didn't use flash and
> go available light. ;-)
>
> Besides any flash I used over the years has always been something
automatic
> no brainer thing.  So please help me with a very simple way to explain
this
> guide number and how to make it work with whatever flash and camera is he
> has.
>
> thanks guys and gals.
> ted
>
>
>
>
>
>
> --
> To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html
>

- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html