EF 300 1:4L IS Lens Hood Operation

[thirdherd]

The illustration shows this lens with a built in hood that extends. How do you get it to extend? I'm reluctant to use any force. Will a filter prevent the hood from extending?

[ebiggs1]

One of my very favorite lenses. The hood locks in place when it is extended if you turn it to the right, clockwise form the camera side but there isn't any lock when it is retracted.  Just slide it forward.

This lens works very well with the 1.4x tel-con. One of the very few I ever use one with. It gives you a 420mm, f5.6 with IS.