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Old Jan 23, 2005, 6:45 PM   #1
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With the Minolta A-200 at 8mp if I were to use full zoom @ 200 and were to use 2X digital what resoltion would I end up with or how many mega-pix would the photo have? If the number is in the area of 4mp would this not be a resonable alternatave to a larger tele zoom lens if only a 4mp res is reqd? If it is not too complicated what is the math to figure this out. Thank you.
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Old Jan 24, 2005, 4:03 PM   #2
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dwssas wrote:
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With the Minolta A-200 at 8mp if I were to use full zoom @ 200 and were to use 2X digital what resolution would I end up with or how many mega-pix would the photo have? If the number is in the area of 4mp would this not be a reasonable alternative to a larger tele zoom lens if only a 4mp res is reqd? If it is not too complicated what is the math to figure this out. Thank you.
Depending upon the resolution you select i.e. RAW, Extra etc depends upon the resolution & size of the saved image; the higher the resolution, the better the quality.

If you 'stick' a x2 telephoto on the front, you will still have nominally the same size/resolution.

I would always recommend taking an image that matches the size of the CCD with lowest compression to obtain the best possible result - I never resize in the camera.

If the required final image size is that which corresponds to 4M, then you can crop the image to suit in Photoshop thus obtaining the required magnification.

Remember that the quality of the final printed image will not potentially be to the same standard as that printed from the uncropped one unless you downsize the printed image proportionally.
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Old Jan 25, 2005, 6:52 AM   #3
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I agree. However if I use Full zoom plus 2X digital zoom and am using max jpeg resolution, on this 8mp camera, what resolution will the resulting photo be at?
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Old Jan 25, 2005, 1:53 PM   #4
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There is no advantage to using digital zoom as this can be done much better outside the camera using Photoshop or similar.

Basically, you are resizing the central portion of the image to fit within the 8 Meg format.

In the attached example, the original image was 682x510 and the central section 342x256 was digitally magnified x 2 to 684x512. The quality of the digitally enlarged image suffers as it has to extrapolate the smaller number of pixels into the larger format and cannot be to the same clarity as an optically focused image.

I have a couple of web sites in which I use images to illustrate walks around the Isle of Wight & Lake District in the UK; all these images are resized to 600x450. So if I have a distant object that is still too small at maximum optical zoom, I can post process this from 1280x960 to 600x450 which effectively gives me just over 2 times magnification - but in reality, I'm just cropping the bit that I want but still retaining the original number of pixels within the 600x450 size thus retaining the originalquality.

If I took the shot at 8 Megs i.e 3264x2448 and cropped to 600x450, I've effectively has a5.5x additional zoom.

This is all based on cropping not resizing - the latter affects quality whereas cropping doesn't.

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Old Jan 25, 2005, 8:40 PM   #5
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Thank you Catbells for taking the effort to explain. I think you have finally put it in a way that even I can understand and it finally makes sense.
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Old Jan 26, 2005, 6:03 PM   #6
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Hi dwssas

Glad to have been of some help.
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