Help with 2X Extender

[blevine15]

I have a EOS 20D with a 100-400mm lens. I mainly photograph birds. I purchased a 2x extender and I can not seem to get a sharp image, (with or without a tripod). Can anyone offer any suggestions.

Thanks,

Bob

[Belmondo]

You lose 2 full f-stops with a 2X extender. At 400mm, your f/5.6 lens becomes f/11, and auto focus won't work as a rule.

[Jon]

Whose extender? the 2X extenders, in general, will seriously degrade image quality. There's also the problem of holding that 800 mm of lens steady at the shutter speeds you get at f/11.

[RichardtheSane]

Are you using manual focus?

To be honest you will have to be as AF will either fail or not work properly. You won't be able to hand hold at that focal lengh and you will need a shutter speed of (ideally) 1/1000 sec. IS will make some difference but not as much here.

If you are using manual focus check the Dioptric adjustment next yo your viewfinder, if that is set incorreclty then you will have no chance on manual focus.