Sags Ol Flashcards
1
Q
What is approx formula
A
y2 x F / 2000(n-1)
2
Q
what is accurate formula
A
r-‘/ r2 - y2
3
Q
how to find radius
A
1000(n-1) / F for front
1000(1-n) / F for back
4
Q
how to know which horriz or vert is thick or thin for e
A
If total F is + = Horiz ethin
If total F is - = Horiz ethick
5
Q
how to find tool power
A
radius of lens using lens n
power of tool using tool n
6
Q
what is tool equation
A
ftool/ ntool-a = flens / nolens -1
7
Q
what happens when need to find power of tool or lens and only have selected measurments
A
use equation to narrow down then finalise with easier way in order to gain final tool power
8
Q
What is CVF
A
way of comparing the high index lens with it’s crown glass equvalent
9
Q
how to work out cvf
A
1.523-1 / ? - 1 Ans - 1 x 100 = % if - = thinner if + = thicker
