Ok, so I've read the f/stop chart page in New To Photography learning plan
I get that these are the magic numbers that equate to halving the diameter of each (hole) as we go from 1.4 to (1.4)^2 = 2 to (1.4)^3 =2.8
and that if I don't touch my and I want to maintain the same amount of entering my image I will need to double the speed of my
OR if I don't touch my and I want to mainain the same amount of entering my image I will need to double the sensitivity to (my )
I understand the relationship between the being a divisor of the focal length of the with the diameter of the
What I don't understand is why I care?
in the chart -
what does knowing that I will let in the same amount of if I leave my as static
and I make diameter half the size
as well as speeding up the by doubling it
as I would if I left it alone mean to my photo?
I'm (so far) quite comfortable with the math's but I don't understand how understanding that relates to the actual photo?
If it's on the next page, I may regret this post, but I am going to post it anyway.