17th April 2008, 09:41 PM
Help Telephoto Aperture
In terms of absolute aperture diameter, does an f5.6 20mm have the same aperture diameter as an f5.6 300mm?
Otherwise, why does an f5.6 300mm have more background blur than an f5.6 20mm? Or is the amount of blur the same just that it appears less DISTRACTING due to the narrower field of view?
Please help thanks....
17th April 2008, 10:49 PM
Re: Help Telephoto Aperture
Relative Aperture ( which is what is often used ) equals to focal length divided by the actual aperture size. Hence nope they r not the same.