Lens hood length / Width ratios

[john_van_v]

This probably affects many of use: dented lens filter threads.

The obvious, and only, solution is a slip-on filters and hoods.

My immediate quesion is this:

23mm D x 65mm W
​

What lenses would this work with, in other words, not block?

My other question is this:

Has any one found and newly updated pages with this kind of angle information for lenses, or how-to's for making hoods.

There was some around, but got deleted or was too obfuscated to understand.

Cheers, John

 

[ferider]

What's the filter size, John ?

 

[john_van_v]

It is 51mm OD, 49mm ID

 

[ferider]

Let's see if I get this right, and forgive the math:

FOV = 2 * atan((65 - 51) / 2 / 23) = 34 degrees. Roughly corresponds to the diagonal field of view of a 75mm lens on full frame.

Hope this helps,

Roland.

 

[john_van_v]

Actually it is what I need then, the oly f1.4 hood -- I was around some hostile people, got nervous, and dropped her!

You are a wunderkind (is that a word?) I suppose we should make a wiki page with your formula.

Gold 200 / Zuiko f1.4, thats my formula for still life