On Wed, 8 Mar 2006 14:14:32 +1300, "David Mitchell" <[EMAIL PROTECTED]> wrote/replied to:
>> High-end Canon bodies have center-point AF which work at f/8 >> instead of the usual f/5.6, at the expense of being bit less >> accurate. > >What is it that stops the AF working past a certain aperture? It >doesn't seem like it should be light levels because there is more to >that than just aperture: A very bright room at f/6.3 would still be >easy enough to focus in, whereas a camera can really struggle to focus >in dim light at f/1.8. What gives? Programmed into cheap bodies by Canon. Gives their Pro bodies a plus, and avoids amateurs complaining about poor focus on the amateur bodies. I use my 10d with the EF100-400L IS with 1.4X extender all the time using the 'tape over contact' method to fool the body into thinking it's really at f5.6. Works great for me. I'm certainly not complaining about anything considering how well it works, but I understand Canon's reasons for physically limiting AF to f5.6 on non Pro bodies. -- Jim Davis, Owner, Eastern Beaver Company: http://easternbeaver.com/ Motorcycle Relay Kits, Powerlet, Centech, Posi-Lock, Parts, Info, Photos K100RSes on both sides of the planet! * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
