Where is f9 & f10 on my meter?

**Ed Brock** · 2-Dec-2008, 09:15

Not that it is going to matter a lot. But on my Fuji 250mm with SF grid inserted, those are my choices. I am guessing that f10 is basically f11. But is f9 closer to f8, halfway between f8 & f11 or somewhere else? Is there a chart somewhere that would show all of these "in-betweeen" settings or should I even care since I only shoot negative and never transparancy?

**BarryS** · 2-Dec-2008, 09:19

http://www.largeformatphotography.in...ws-factor.html

Look halfway down the page. f/8, f/9, f/10, and f/11 are separated by 1/3 stops.

**Dan Fromm** · 2-Dec-2008, 10:14

Ed, if you must be obsessive, get a broken Weston Master V and use the calculator.

**Arne Croell** · 2-Dec-2008, 11:03

Originally Posted by BarryS

http://www.largeformatphotography.in...ws-factor.html

Look halfway down the page. f/8, f/9, f/10, and f/11 are separated by 1/3 stops.

Yes.. In general, since full stops are separated by the square root of 2=1.414 in their numerical values (and then rounded), ⅓ of a stop is equivalent to the 6th root of 2 or a factor of 1.1225. So 16⅓ is 16·1.1225 or approximately 18 as a numerical value. Remembering this comes in handy when using odd starting numbers, like in the original posters case. Another example: the Fujinon C 450mm has an opening of 12.5 ≈ 11·1.1225, or 11⅓...