I've read stickies but Im still unsure
there are lens like
17-50mm (for wide angle)
17-70mm (for walkabout)
18-250mm (for telephoto)
does it mean 18-250mm is able to perform as a 17-50mm and 17-70mm lens also? if so why do people get different types of lens rather than a single lens with a broad range?
another question is- do I need to get a lens with auto focus?
or issit people by diffrent manual focus lens with lesser range because cheap?
if so i can just buy 18-250mm with AF right?