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Learning the f-stop table
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?
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
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
Thanks John - that is helpful. Next step - to chuck in the 1/3 stop increments!
... or even 1/3rd stops!!
Why bother?
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
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 !
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)
