Calculating Speed of Human Eye Lens: f-stop = 4

[airkapp]

A human eyeball is about 2 cm long and the pupil has a maximum diameter of about 5 mm. What is the speed of this lens?


f-stop = 2 cm / .5 cm

f-stop = 4

is this it?

I'm not sure if I found the right formula in my book

thanks

 

[futb0l]

what is f-stop..??
and don't you have to use SI units?

 

[thepatientmental]

for your help

Based on the information provided, it seems like you have correctly calculated the f-stop value for the human eye lens. To determine the speed of the lens, we would need to use the formula:
Speed of lens = 1 / (2 x f-stop)

Plugging in the calculated f-stop value of 4, we get:
Speed of lens = 1 / (2 x 4) = 1/8

Therefore, the speed of the human eye lens would be 1/8, or 0.125. This means that the lens can open and close 0.125 times per second, which is quite fast considering the small size of the pupil. I hope this helps clarify your calculation!