Optics, perhaps you should write about it with a capital letter. Before writing this article, I asked my friend, which is used by digital cameras for a long time, what is most important in the camera to his eye, and he replied: "Of course ..... OPTICS and sensitivity." One can go to talk about that important, but ...
When choosing a camera, see what it is optics. The company often puts Sony on its optics equipment of German company Carl Zeiss (Carl Zeiss Vario Sonnar) is undoubtedly great, because it is better to just not there. Kodak is also using optician German company SCHNEIDER-KREUZNACH VARIOGON, which is also very good. Such companies as Canon, Nikon and Olympus use their optics, but because their experience in the photographic technique is very high, then the optics are put delicious. So when choosing a camera always see who made those lenses that are in your future camera. In advance, I can say that in the low-cost models ($ 300) and the models are not well-known brands on the expensive optics can not count. So even if you buy a 5 mega pixel camera is an unknown brand with a simple optics, the meaning of such a large matrix is reduced to zero, the excellent quality you can not tell.
ISO (aperture) is also very important for any camera. The higher it is, the more good shots will be made at dusk or dark room, that is, on the resulting images will be less than the so-called artifacts (noise, white dots). But do not think that the high sensitivity can shoot in total darkness. A lot of companies indicate the sensitivity in relation to conventional film: 100, 200, 400 and above ... The higher the number, the better. Also, sensitivity to light may be specified in the suites: 0,5 Lux, 0,7 Lux (usually in lux light sensitivity is indicated for the cameras), in this case, the smaller the number, the better.
Finally, sensitivity to light may be given in this form, f/2.8 - 8.0, lower than the figure lower, the better (usually in such a luminosity is given by the condition of Zoom'a on the camera). Consider the example of a camera Kodak 6490, this model approximation zoom or 10x and with minimal zoom'e aperture 2.8, at 10 and approaching aperture is 8.0.