Shooting lower than max megapixels

[Schtibbie]

This is a REALLY nerdly question, but... I'm getting a new super-compact camera to replace my old 4-megapixel one that died. This is a "throw it in the pocket and take my son to the park" thing. Everything available is 8-10 megapixels with no increase in sensor size, so I *know* about the noise problems. I'm hacked off about it but what can I do..

Question: If I set one of these high-MP cameras to its 4-megapixel mode (as I'm ok with that and don't have a big hard drive), does a camera use ALL of the pixels on its sensor and then average the pixels out down to 4mp, or does it hit "every other" pixel on the sensor and take that? In other words, would the noise issues in individual pixels at 10mp be effectively smoothed out by shooting in a lower mode?

 

[cube]

If the camera is capable of pixel binning, it will be more sensitive at lower resolutions.

But you have to check such feature is not only available for Hi-ISO.

 

[compuwar]

In other words, would the noise issues in individual pixels at 10mp be effectively smoothed out by shooting in a lower mode?

No, the noise is related to the size of the photosites, so you're going to get the same effective noise.

 

[Westside guy]

It's very important to check reviews of photo quality with compact cameras, because the image quality can very so much. Here's a recent Luminous Landscape review of two cameras that illustrates this nicely.

Here's a great article on Digital Photography review that talks about high ISO noise on compact digital cameras.