Zoom Confusion

[geofolk]

Several people have wondered why they cannot "zoom" when the Commando camera is set to 5 megapixels. The simple answer is that you gain nothing from it other than cropping the picture. I don't know if this has been explained well but digital "zooming" is much different than optical "zooming". Optical zooming is accomplished with the use of different lenses and/or different lens settings (very different from digital zooming) and the resolution is determined by the film ASA. Digital zooming relates to the number of pixels provided by the charge-coupled-device or the "film" resolution chip in the camera. This chip (resolution) cannot be changed without physically changing the chip. With the same pixel resolution (say 5 megapixels), digital zoom actually does not zoom in the same sense that optical zooming does. Digital zooming with a camera is similar to what you can do with Photoshop by cropping the image and resetting the image size. One way to think of digital zooming is to imagine a grid (like a spread sheet-rows and columns), say 10X10 or 100 pixels (1/100 mega pixel ccd) in your field of view. When you digitally zoom your are selecting only a part of this grid but at the same resolution so you in essence loose part of the image without increasing the resolution. There are algorithims that will estimate new pixel information base on nearby pixels (kind of an averaging).
The most important factor in quality optics has commonly been the quality of the lens and their ability to magnify and not necessarily the resolution of the film or ccd.

 

[jonathon6017]

A lot of people do not understand this but what I find funny is that if you take a picture but then do your cropping and re-sizing in Gimp(or Photoshop), then it actually looks better then if you were to use digital zoom in the camera. I guess it has something to do with different algorithms and a better processor.