DOF when using "zoom in to focus" technique

[Nick Poteri]

Hi, I'm using a TRV950 for short film development. I use the following technique to focus:
(1) I zoom in to fill the frame with the subject
(2) Focus
(3) Zoom out

While this is foolproof, I'm curious how this technique might affect the depth of field. Is it the case that I will end up with a greater depth of field than if I were to focus at the original focal length without first zooming in?

Thanks,
Nick.

[Jeff Donald]

The three primary factors of DOF are F Number (aperture), Distance to Subject, and Focal Length of the Lens. Your method of achieving critical focus is fine and will not effect DOF.