I count 2, 4, 8, 16, 32, 64 on my fingers and six fingers puts me between 6 & 7 stops. How would you do it? -----Original Message----- From: ADavidhazy <andpph@xxxxxxx> Sender: owner-photoforum@xxxxxxxxxxxxxxxxxx Date: Fri, 21 Jan 2011 10:53:18 To: List for Photo/Imaging Educators - Professionals - Students<photoforum@xxxxxxxxxxxxxxxxxx> Reply-to: photoforum@xxxxxxxxxxxxxxxxxx Subject: Re: f number adjustment to increase light level Agreed ... factors of 2 are easy but what if you wanted a factor of 4 or 6 or 75? I will agree again that is is academic but in certain obscure and unanticipated applications it might be useful to know this if you want to determine a specific f number rather than just guessing at it. The question was asked in an academic setting - part of the overall technical education of photo technology students. Andy PS: Interestingly ... most students here don't know what a photographic enlarger is or what a light meter is either! The digital age is upon us! ;) <- wink! On Jan 21, 2011, at 10:12 AM, Lew wrote: > Yes, but a quick look at any lens or light meter tells you just as > much without any calculations at all. Each stop signifies a factor > of 2, so to get 4x the amount of light, click over 2 stops & you're > done. Teaching a student all this math (if this is what the thread > is about, I wasn't in on the beginning) is very academic. It's not > anything a photographer with a camera in hand would ever do.
