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I suspect that the CX450 is offering higher digital zoom. What are the started max zoom ratios for both models?
The Panasonics go up to 1500x. I've never used this as it would be too pixellated and soft. Digital zoom is like resizing a small part of an JPEG imaqe up to full-size. Imagine resizing something occupying 198x108 of the sensor area -> 1980x1080. That's a 10x zoom. OK if done optically. But most camcorders reach an optical zoom max of 10x or 20x. So to go to 1500x, after 20x of optical zooming in, would require a further 75x of digital zooming/upsizing. There's no way this will look sharp. And it will probably look highly pixellated too.
Since modern camcorder sensors have more MP than is necessary for the Full HD framesize (2MP), there is usually some leeway. For example. If the sensor capture area of the original image is 8MP (3960x2160), 1x requires a 1/2x downsize to fit the captured sensor pixels within the final Full HD frame, so 2x zoom-in is actually back to the original 1:1 pixel correspondence between sensor and final image. For example, my Panasonic HCV750 & V770 camcorders have:
up to 20x "Optical" zoomup to 50x "Intelligent" zoomup to 60x "Digital" zoomup to 1500x "Digital" zoom
My understanding of this is that it's possible to zoom up to 50x before the weaknesses of digital zooming come into play.
BTW, There's no free lunch. 20x of high-quality optical zoom is extremely difficult to achieve in a professional video lens costing 10s of thousands of dollars, let alone the small cheapie lenses used in a consumer camcorder. At high optical camcorder zoom ratios, the image will tend to be softer and have more geometric and chromatic aberrations than is desirable. But consumer expectations aren't that high anyway and the moving images tends to focus your attention on other things. The loss of quality will be obvious though if you capture a still from a frame holding an image taken with this level of zooming.
Dan. |
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2-12-2019 02:19:37
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