Is it normal for live view to freeze when focusing with a point & shoot camera?

Question

I went to a Best Buy recently and tried a few point-and-shoot cameras, among which the Canon G15, Canon SX260, and Canon SX50. With all of them, I noticed that the live view freezes for a short time when I half-press the shutter button to focus.

(I am NOT talking about shutter lag, but about lag when focusing. I don't know if there is a proper term for this, so I will try to explain what I mean. If I pan the camera from left to right, the live view updates fast enough that I do not notice any lag. Now, if I pan the camera again, and half-press to focus while panning, the live view freezes for a noticeable split second, then resumes updating again. Panning has nothing to do with this -- it just makes the freezing more noticeable. Also, after focusing I just release the shutter button without taking the shot. So I am NOT talking about the "review" feature.)

Is this freeze-when-focusing an inherent flaw in most point-and-shoot cameras, or is there some setting I can change to get rid of it?

The freezing was noticeable in all point-and-shoots I tried at Best Buy, except some Nikon ones. What I find baffling is that my 4-year-old Panasonic FZ28 shows no noticeable freezing at all. Surely point-and-shoots must have improved, not regressed, since then!

Answer 1

There is nothing you can do about for a particular model. While almost all fixed-lens cameras experience delay, it can be made extremely small. This occurs because to focus a camera using contrast-detection must read the sensor in a loop all the while it moves the lens back and forth to determine the point of highest contrast (meaning focus is established).

Higher-end cameras with faster sensors, some of which can be read at 240hz, can experience a much shorter delay. This is of course something manufacturers put a higher price tag on, so I am not aware of any point-and-shoot which uses one of these sensors at this time. It actually requires a very fast CMOS sensor, so any CCD-based models are out of the question.