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Old Sep 24, 2005, 11:01 AM   #11
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http://www.stevesforums.com/forums/v...mp;forum_id=92

Cae.... this is why I created a thread like that. it is not hard to use the software provided with the cameras today just we overlook the simplist details .


Not of a perfect video but shows you in a video form, anda stil shot
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Old Sep 26, 2005, 11:54 PM   #12
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Caelum wrote:
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sgspirit, I didn't think about zooming for stills, but that makes sense. Although my own thoughts on digital zooming for stills is that it's best done on the PC since good graphics software can do cropping and/orhigh quality resampling better than what the cameras can do themselves. For video, though, it would represent too much work.

What's your experience with video zooming sgspirit? I was talking about my very limited experience with these hybrid camcorders and that sample C5 video. Does it appear to you that the cameras do not take advantage of the extra megapixels for video when zooming?
Definitely not. Still images clipped out of videos definitely are 640x480. Unless they are the beginning or reference frames, they also have compression losses.

Any zoom during video noticably costs quality. And using the motion stabilization amounts to a small amount of zoom to begin with.

I'll have to re-check this on the V1. It's definitely quite different from the 720, as indicated by the vastly sharper reproduction of fast-moving objects.

I'm trying to think this through, and it contradicts what I said before. Say you're looking at a scene. For stills, the subject matter fills the sensor, and shows up that way on the screen. You decide to take a video instead. Presumably, since you're not changing the focus, the subject matter must still be falling on the entire sensor, and certainly still shows up the same way on the sensor.

So how is the still recorded at high resolution, and the video at 640x480? Rather than scan a small portion of the sensor as I suggested earlier, it must record a subset of the pixels spread across the whole sensor. Now, if that is correct, then what effect would zooming have?

Zooming would reduce the area of the sensor in use, like cropping. The remaining pixels in the scanned area obviously would yield a lower-quality image, since there's no way (ignoring extrapolation) to "make" more pixels. But zooming in video, with lots of resolution to spare, should, as you described, be able to maintain the same resolution, right down to a 640x480 area. Only at that point would it run out of pixels to choose between to maintain resolution. So, since these cameras do lose resolution when zooming in video, they must not be taking advantage of the opportunity to use all those available pixels. There must be some sort of a pixel mapping algorithm required to do this.

Since they lose resolution while zooming in video, it must mean that they start with a subset selection of pixels to get the 640x480 image, then somehow choose diminishing subsets of those 640x480 pixels to achieve the zoom. This itself would require pixel mapping software. So why not do it the better way?

Like, is a 2x zoom just a 320x240 subset of the 640x480 pixel set? Is that why these cameras zoom in steps? This seems pretty crude, but I guess it's a lot easier to do than re-mapping the pixel selection over the whole sensor. If I'm making sense, then a digital zoom in video mode could be as good as an optical zoom right down to a 640x480 portion of the sensor. On a 3Mp sensor, this would give over a 3x zoom with no quality loss.

Non-zoomed video (1x) on a 3.1Mp sensor would be using every third pixel, across and down. A 2x zoom would use every second pixel, but from a smaller portion of the sensor. A 3x zoom would use every pixel from a 640x480 portion of the sensor. Intermediate zooms, like 1.5, could use a software combination of the 1x and the 2x zoom. Seems simple enough that I must be mistaken somehow, or it would be done this way.

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Old Sep 27, 2005, 1:04 PM   #13
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It's what it looks like to me... for a 5mp digicam, when in video mode I suspect they only use every fourth pixel (= VGA res), evenwhen you zoom. When I think about it, it's much simpler for the camera, computing wise, and perhaps it's also energy efficient for the CMOS/CCD? Like I mentionned before if processing power was not an issue the entire sensor would be utilized and the image simply resampled to video size for every frame and during a zoom it would use smaller concentric areas of the entire sensor, again resampled to video size. But even a powerful PC (today)cannot do that in real time with 5mp raw frames (remember that's12MB of raw data (5Mpixelsx 3(RBG) per frame pre-compression).
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Old Sep 27, 2005, 3:25 PM   #14
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I don't think it has to process 12mb of raw data to use the full 5mp sensor for digital zoom in video mode. At 1x zoom, couldn't they simply use a 640x480 grid of specific pixels spread out uniformly accross the whole ccd/cmos array? Then as you press the zoom button, an algorithym is applied to this grid that gradually and uniformly shrinks it towards the middle of the array until the very middle 640x480 pixels of the ccd/cmos are used at maximum zoom. This way, you are still processing only 640x480 pixels with the addition of only an algormithm applied to it. With a fixed lens, this seems like it would make a very clean zoom rather easily without the pixelization we are currently having, in my layman opinion. What do you think? Why hasn't digilife or others picked up on this?
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Old Sep 28, 2005, 5:16 AM   #15
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They must have a good technical reason, I have no idea why, heck I can't even multiply5 X3 properly! (arrg) Perhaps it's that turning on and off different sensor pixels or an unevendistribution of themduring a zoom might cause even more noticeable noise/distortion? For the full sensor resample, I was just talking ideal, not realistic.
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Old Oct 5, 2005, 12:28 PM   #16
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Hello,
I was about to buy the Microtek Take-it MV500 as well but at tigerdirect.com thay don't have it anymore. Do you know any place where I can buy it? Especially online?
thanks so much,
Poly
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Old Oct 5, 2005, 1:16 PM   #17
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In USA, shopnbc.com has a version in black, but at a high price.

In Canada, try payless.ca *** sorry no longer there ***
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Old Oct 24, 2005, 1:11 PM   #18
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Hi Has any one got an answer about the Microtek MV500. If you were more interested in still pictures with the video option a so so will you buy this camera or stay with a 5.1mp digital camera. Need help. Got one already, just wondering if I should keep it or get the DGX 5.1mp from tiger direct for $99.99. HELP
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Old Oct 24, 2005, 2:05 PM   #19
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poly70 wrote:
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Hello,
I was about to buy the Microtek Take-it MV500 as well but at tigerdirect.com thay don't have it anymore. Do you know any place where I can buy it? Especially online?
thanks so much,
Poly
Did you find one yet? Saw a lot of them at tiger direect still @ US $129.99. If u got one how do u like it?. Any advice as to some one investing on one.
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Old Oct 24, 2005, 9:08 PM   #20
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Tech wanna-be wrote:
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Hi Has any one got an answer about the Microtek MV500. If you were more interested in still pictures with the video option a so so will you buy this camera or stay with a 5.1mp digital camera. Need help. Got one already, just wondering if I should keep it or get the DGX 5.1mp from tiger direct for $99.99. HELP
Hi Techwanna-be,

Welcome to the forum.

Your choice of emphasis on still pictures would make a digital still camera a better choice. Just get one with MPEG4 video, so you can take enough video to get used to it and see if you'd like to do more.

Usually dsc's have optical zooms, a feature important to stills, that only the more costly hybrids have. On the other hand, getting a dsc usually means not having an mp3 player, if that matters to you.

The "What Camera to Buy" forum has a topic that lists dsc's that do 640x480 video at 30 frames per second - sort of a minimum standard.

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