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Learning the f-stop table


stevekhart 15 4.5k 3 United Kingdom
13 Jun 2007 10:49AM
Something I wish I could do in my head, but still haven't mastered it, is learning my f-stop table. Are there any tricks or tips for learning it?
Henchard 16 2.7k 1 United Kingdom
13 Jun 2007 11:00AM
This was how someone told me - You only have to remember two numbers; 1 and 1.4. Double each one alternately and you will have two series:

1, 2, 4, 8, 16, 32 and 1.4, 2.8, 5.6, 11, 22

So, combining the two sequences in numerical order gives the full sequence:

1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32
dougv 17 8.4k 3 England
13 Jun 2007 11:26AM
Nice and easy.
I think even I could remember that.
Smile
IanA 17 3.0k 12 England
13 Jun 2007 11:37AM
That's great..... until you find out the next one is f/45!!!! Wink
stevekhart 15 4.5k 3 United Kingdom
13 Jun 2007 11:38AM
Thanks John - that is helpful. Next step - to chuck in the 1/3 stop increments!
c_evans99 17 7.0k 1 Wales
13 Jun 2007 12:15PM
Try using prewar cameras where your aperture scale is likely to be based on multiples of f6.3 Smile
Carabosse 17 41.5k 270 England
13 Jun 2007 12:40PM
Now try learning half-stops as well! Wink
User_Removed 17 17.9k 8 Norway
13 Jun 2007 1:12PM
... or even 1/3rd stops!!

Wink
Kris_Dutson 18 8.2k 1 England
13 Jun 2007 1:50PM
Why bother?

Wink
stevekhart 15 4.5k 3 United Kingdom
13 Jun 2007 2:00PM
It's not high on my list, but would be useful nonetheless. I think most of it comes with time, but when setting up lighting ratios it can be handy rather than dialing it on your camera to see what the answer should be Wink
JohnHorne 16 1.0k
13 Jun 2007 2:37PM

Quote:That's great..... until you find out the next one is f/45


The problem, Ian, is rounding. The sequence should really be

... 4, 5.6, 8, 11.2, 16, 22.4, 32, 44.8 ...

11.2 is expressed as f/11; 22.4 is expressed as f/22; and 44.8 as f/45. Not that many lenses get that far !
Carabosse 17 41.5k 270 England
13 Jun 2007 3:58PM
When I was about 14, I made my own Exposure Value table... I think I still have it somewhere.

An EV table can be useful as a quick guide.Smile
takui neko 17 849 11 Spain
13 Jun 2007 5:16PM

Quote:The problem, Ian, is rounding. The sequence should really be:
... 4, 5.6, 8, 11.2, 16, 22.4, 32, 44.8 ...11.2 is expressed as f/11; 22.4 is expressed as f/22; and 44.8 as f/45.



Erhm...

The sequence is each number multiplied by 1.4142135623730950488016887242097 to get the next f-stop
which is roughly this:
HERE
forget the 1/4, 1/2 & 3/4 stops on that table.

That should help I think... :o)

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