Ah ... OK, then the confusion is more a matter of terminology. I understand because, with the constant "f-stop" zooms that I have, I can see the aperture change.
And while technically you're correct, in practice many people use the terms interchangably, probably out of custom when aperture and f-stop were more closely linked to being one and the same. T Rittenhouse wrote: > > Actually, a constant f-stop zoom is a variable aperture zoom. The aperture > has to vary over the zoom range to keep the f-stop constant. Variable f-stop > lenses may have a fixed aperture (that is the aperture stays the same across > the entire zoom range), or a stepped aperture (one that stays the same over > part of the zoom range) which allows a smaller f-stop variation across the > entire zoom range but is still cheaper than a fixed f-stop lens. Basically a > fixed f-stop zoom lens is bigger, heavier, and more expensive than a > variable f-stop lens. Once again as I have pointed out before, aperture and > f-stop are not really interchangeable terms. -- Shel Belinkoff mailto:[EMAIL PROTECTED] http://home.earthlink.net/~belinkoff/ http://home.earthlink.net/~belinkoff/darkroom-rentals/index.html - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
