I have a 50E but cannot seem to be able to figure out how to do Depth of field preview (the manual is a bit vague). Can the EOSs do the old style Step Down preview? Some of us old timers may recall you used to push the timer release inwards (on a FTB towards the FD lense) to get the lense appreture to close.

-- Kim Ko (fortec@sprint.com.au), September 10, 2001

Answers

There are two ways of using DOF preview on the EOS 50E.

1. If you use ECF, and it is enabled, then select your aperture (eg F16), and, once focusing is complete, look at the little parallelogram in the top left corner of the viewfinder. This tells the ECF system you want the aperture stopped down. To open up the aperture again, release pressure on the shutter button.

2. Set custom function 4 to put DOF preview onto the AE Lock button. Then, when you want to preview the aperture, press the AE lock button. To open up the aperture again, release the AE Lock button.

These two methods also work for the EOS 5/A2e. Canon have now done away with it, and the EOS 3 and EOS 30 (Elan 7) have a proper DOF preview button on the lens throat.

-- Isaac Sibson (isibson@hotmail.com), September 10, 2001.

Just an addendum to Isaac’s answer:

(1) To engage DOF using ECF, you must (a) hold down the shutter button and (b) be in one-shot AF mode (I don’t remember if it works in that auto switching AF mode). (2) Custom Function 4, option 2.

As a fellow old timer, who owned a Canon F-1 system, its easier to use than it sounds (especially method 2). Just be thankful that your 50E even has a DOF preview function. Most of it’s competition did not have that feature.

-- Ken Katz (socks@bestweb.net), September 10, 2001.

Don't forget to also utilize DEP mode to assign near/far depth points. Then use DOF preview to give the view a quick once-over.

-- Peter Phan (pphan01@hotmail.com), September 10, 2001.