Re: Fast Lenses: Why so expensive?

[Ernest Nitka <enitka@twcny.rr.com>]

Kevin - simply put the faster the lens the more correction has to be 
designed into the lens so the distortions don't get the best of the 
image.  The opposite of this design requirement is the pin hole camera - a 
hole without a lens at say f/256 will give you an image albeit not terribly 
sharp.  The more technical on the list can give you all the technical reasons.

ernie


At 11:42 AM 12/24/02 -0500, you wrote:
> Hello all,
>
> I have a question concerning fast lenses as to why they are so expensive. 
> I under stand that a fast lens allow for more light by providing a larger 
> diaphragm opening. I am curious as to why this results in such a large 
> price increase between, for example,a  f3.5  and a f1.4 lens. Anyone know 
> the answer?
>
> Thanks
> Kevin