couple of basic questions about digital cameras

[dinoadventures]

Start with clean light, keep it clean the whole way, do as little to it as possible, and you will have a good picture. Every time you try and cut a corner, every time you try for a free lunch, it will degrade the quality of your image.

exactly. the lens matters. a million megapixels and the best sensor on earth mean nothing if the light hitting it sucks. if you don't expect to use flash in anything but broad daylight, check the maximum aperture on the lens. the smaller the number the better. if you can maintain a constant f/2.8 throughout the zoom range, you're going to have lots more low-light versatility. if the number is like f/5.6 you're going to be relying on the light sensitivity performance of the sensor, which will give you a crap image on a point-and-shoot. another thing is to make sure it has an optical viewfinder in addition to the LCD. you might not think it's a big deal but it goes a long way towards battery conservation and it makes it a whole lot easier to shoot in bright light.

you wouldn't expect a good knife from a box labeled '$5 Sale' so don't expect free lunch from camera manufacturers. resist the urge to be cheap and do things right the first time. just because something is a deal doesn't mean you should jump on it blindly. determine your needs and carefully select the correct tool for the job. if you can't afford to put money into a quality digital camera, pro-level film cameras are available for just a few hundred bucks.

 

[huugh]

You haven't looked at some of the really high-end professional, studio stuff.

I know there were some experiments with triple exposure to monochromatic chip while seperate R/G/B filters were used for exposure.
I would really appreciate you taking me to school in area of 3 chip digital cameras so please provide a link, I am really interested.

3CCD in camcoders are basically no big deal - they are so small and with so low resolution that they can use prism of not-so-expensive quality, and chips can be aligned without special effort

For the 3CCD SLR you need:
special lens!
built-in high quality prism
exactly align high resolution chips
space for three chips, each of considerably large size

...

CCD also differs from CMOS in following:
CCD chip amplifies the signal for the group of pixels.
CMOS amplifies the signal for each pixel separately.
That's why CMOS is immune to common mistake of CCD: blooming.
Decay of signal (if I understand you right you mean noise) is created by the inducing charge by other source than light, e.g. temperature, electromagnetic radiation etc. If you have intense light stream it generates strong charge compared to ambient sources causing noise. Then you will have good signal to noise ratio. If you have poor light conditions, your signal to noise ratio will become worse and noise will appear in the picture (that is what you encounter when using high sensitivy). In both cases the signal has to be amplified. If signal and noise have similiary strong charge they can be misplaced.

Anyway I think you attach too much importance to the chip power consumption. What consumes most power in cameras is LCD display and moving mechanical parts.