"Mark" wrote in message
om...
Hello,

I own a Sony Cybershot 5.0 Megapixel camera (cybershot DSC-P10). My
buddy owns an Olympia 4.0 Megapixel camera.

We both set our cameras to the highest resolution.

When I take pictures, the size of the resulting jpeg file is
approximate 2 meg, give or take 100K (on average).

When my buddy takes pictures, the size of the resulting jpeg files is
larger - closer to 2.5 Meg.

Does anyone know why it is like this considering the different
megapixel specification for each camera? I would have thought that the
5 meg camera would have larger jpegs.

Different compression ratios is the biggest reason for the difference, but
noise contributes to compression variability among cameras, too. The more
contiguous pixel redundancy in a photo, the more it can be compressed;
cameras producing noisier pictures have decreased pixel redundancy and hence
compress to larger file sizes. To see this effect, use a noise-reduction
program such as NeatImage and save the same picture several times using
different noise redunction amounts; the more "noise" is reduced, the
smaller the resulting jpeg.