SWMBO has a pretty nice camera, a Panasonic DMC-FZ18 with an 18x optical zoom lens on it.

In the setup menu I have the option of turning on 4x digital zoom, giving it a total zoom ratio of 72x.

With digital zoom turned on, when I zoom from widest angle (28mm equivalent) to maximum zoom (~2000mm equivalent) the camera zooms from 1x to 18x, then pauses for about one second before continuing on to the 72x maximum.

Obviously once past the 18x optical zoom range, the digitally enhanced zoom offers reduced picture quality. The question I have is this: With the digital zoom switched on, is there any degradation of picture quality in the 1x -- 18x range compared to having digital zoom switched off? And if there is no degradation (as appears to be the case) why bother to have the option of disabling the digital zoom?

tanstaafl.

There is no degradation with digital zoom switched on between 1-18x. I personally keep the digital zoom feature turned off just to make sure I don't go over the optical zoom threshold by accident.

What Rob said

Yeah, that little "pause" is there to warn you that you're about to push past the optical zoom into the digital zoom, which is blurry compared to the optical zoom. The reason one might disable it is if you totally hate the blurriness of the digital zoom and, as Robricc said, don't want to accidentally push past that "pause" no matter what.

Makes little sense to me to preclude even the possibility of getting a photo (even at reduced quality) that you might otherwise have gotten.

Although I suppose that isn't really the case -- the shot taken at 18x then cropped and blown up via imaging software in your computer to give the same field of view that the camera would have seen at 72x would be the same as if you had actually taken the picture at 72x to begin with. Maybe even better quality if the imaging software in the computer is better than the camera's.

I'll leave the digital zoom on if for no other reason than it provides me with a pretty good binocu... uhhh, monocular.

tanstaafl.

While I would never use digital zoom on my proper camera (not that it actually has one). Having digital zoom on phones and video cameras can actually be quite useful. The digital zoom on my old Nokia N95 was actually pretty good.