> The two low points for the lens is the slow max aperture and the > length it extends when zoomed. It is not a lens that can be used > handheld (over 300mm), nor is it very useful for sporting events (due > to the speed). > > I find that I get more use from my APO 300/F4. When I need the extra > reach the APO 1.4x in combo with the 300 gives a little better > results compared to the 170-500, in a package that is easier to > manage. Of course this combo only reaches 420mm so it is not an perfect > replacement for the 500mm.
I have the 135-400, the speed is a little better but the extension when zoomed is troublesome. I occasionally use the lens as a wakkabout lens for wildlife. Regarding the 300 f/4 APO, this is a fine lens, it's a varifocal design, at infinity it is reported to be 321mm in focal length IIRC making the lens around 450mm when fitted with the 1.4 EX converter and focused at infinity. Regards, John John Whittingham Technician "you can't be optimistic with a misty optic" ---------------------------------------------------------------------------------------------------- The information transmitted is intended only for the person to whom it is addressed and may contain confidential and/or privileged material. If you have received an email in error please notify Carmel College on [EMAIL PROTECTED] then delete all copies of it from your systems. Although Carmel College scans incoming and outgoing emails and email attachments for viruses we cannot guarantee a communication to be free of all viruses nor accept any responsibility for viruses. Although Carmel College monitors incoming and outgoing emails for inappropriate content, the college cannot be held responsible for the views or expressions of the author. The views expressed may not necessarily be those of Carmel College and Carmel College cannot be held responsible for any loss or injury resulting from the contents of a message. ----------------------------------------------------------------------------------------------------
