Digital Camera World on MSN5 个月
How do you choose the right focal length of lens to use for your photography?
You can have the best camera for beginners, but if you don't truly understand focal length, you'll struggle to pick the right ...
BBC24 天
The lens power equation
\(power \ of \ a \ lens \ (D) = \frac{1}{focal \ length \ (m)}\) A lens has a power of -3.33 dioptres. Calculate the focal length and state what type of lens it is.