good info on lenses

[jann1033]

basic easy to understand info ( ie what is ca , how lenses are put together etc) that i thought was well done.
http://www.digitalphotopro.com/gear/lenses/fast-lenses-on-sub-full-frame-sensors.html http://www.digitalphotopro.com/gear/lenses/lens-tech.html
i have always hesitated to buy digital lenses in case i since eventually i want to upgrade to a full frame but the first one mentions using full frame lenses on digital can effect photo sharpness...maybe the best is just sell them when you upgrade. food for thought.