12X Zoom vs. 8 megapixel?

[rogerrabbit]

I am wanting a high zoom camera with a 640x480 video capability. I have been eyeing the Dimage Z3 with 4 megapixels, but are seeing higher resolution cameras (i.e. Dimage A2, etc.) with 8 megapixels, but a smaller 7x zoom.

Does the 8 megapixel replace the difference in zoom? Also, I like pictures to be under 1 MB, therefore, by possibly going with the 8 megapixel, is this the wrong idea?

Thank you.:?

[JimC]

rogerrabbit wrote:

I am wanting a high zoom camera with a 640x480 video capability. I have been eyeing the Dimage Z3 with 4 megapixels, but are seeing higher resolution cameras (i.e. Dimage A2, etc.) with 8 megapixels, but a smaller 7x zoom.

Does the 8 megapixel replace the difference in zoom? Also, I like pictures to be under 1 MB, therefore, by possibly going with the 8 megapixel, is this the wrong idea?

If you crop a photo to make it look like twice as much optical zoom is used, you end up with only 1/4 the original resolution (because resolution is computed by multiplying the width of the image in pixels by the height of the image).

So, if you took an 8MP photo at 200mmm equivalent focal length with the A2 (maximum zoom); and cropped it to look like you used a 400mm optical zoom; you would end up with 2 Megapixels of detail representing your subject.

Here is a table of popular long zoom models that shows you how they compare.

Note that even a 2 Megapixel Model like the Panasonic FZ1 at 420mm equivalent focal length, can capturemore subject detail at full zoom, compared to an 8 Megapixel Model like the DiMAGE A2 at it's 200mm equivalent maximum zoom:

http://www.geocities.com/digital_ray...oomzoomv6.html

Of course, you have to decide how often you'll need to use full zoom and crop photos, too. If the majority of your photos won't need cropping when you're at 200mm equivalent focal length with a model like the A2, then take this into consideration. Also, you indicate that you would not need more than 1MP (I assume that the photos won't be printed at larger sizes, or will be used for web display only).