What influences a lens' max / min aperture?

[michaelg]

And why do prime lenses have a much wider maximum aperture than zoom lenses?

Maybe this is really obvious but I have always been curious, especially re the more expensive prime lenses having a wider maximum aperture than the "entry level" versions....

 

[Richard King]

And why do prime lenses have a much wider maximum aperture than zoom lenses?

Maybe this is really obvious but I have always been curious, especially re the more expensive prime lenses having a wider maximum aperture than the "entry level" versions....

there is less in a prime lens, so the designers have more space to work in... that often means they can mechanically get an apeture wider

the more expensive lenses have biger front elements, and more design in the shape of the lens surfaces. This combines in the opportunity to go for a wider apeture, and/or better optical performance

 

[magicaxeman]

Size and weight of the optical elements.

A prime can have as little as 3 or as many as 7 elements but a zoom will generally have around 14.. thats a lot of premium glass.

 

[michaelg]

Thanks, guys!