How is there so much digital zoom on camcorders?

800x, 1200x, etc.

[MatthewHSE]

I've got a decent 6-megapixel digital camera that takes fairly well-detailed pictures, yet using the full 4x digital zoom totally butchers image quality.

How, then, can they pack hundreds of times more magnification into a camcorder, which I assume is capturing imagery at much lower resolution in the first place? I mean, I've seen some camcorders with over 1200x digital zoom, on top of ~35-40x optical zoom, for a grand total of nearly 50,000x magnification.

Can they get decent video quality at those zoom levels? And if so, why is my still camera any different?

[thecoalman]

There is no replacement for optics, digital zoom is just a marketing gimmick and IMO should never be used with either a still camera or video camera. This zooming effect can be accomplished with your image editor or video editor usually at a much higher quality than your the device can produce.

I don't know where you got your info about the digital zoom on cams but I have prosumer Canon GL2 with 20X optical that can be extended to 100X with digital. The artifacts are almost immediately apparent when using the digital, needless to say I have the digital zoom disabled.

My cam doesn't do a 20X times 100X for total zoom capability and I doubt others do either. If you have digital zoom enabled the slider for zoom level on the LCD panel will go up to 100, at 20 there is line to indicate the threshold between optical and digital. At 100X the video is very blurry and pretty much unusable under any circumstances.

Technically if they wanted too they could make them 1 million X but the only thing you're going to see is a blob of color.

You are correct about the resolution, a DV cam is 720X480(576 for PAL) or a little over .3 megapixels. The newer HD cams may be able to have higher zoom levels because of the increased resolution but it still no replacement for glass.

[MatthewHSE]

Okay, so it's pretty much a useless feature that sells well. I kind of figured that had to be it. Thanks for the clarification!

[BeeDeeDubbleU]

It's a bit like the companies who sell up to 20 MB broadband - totally misleading and designed to attract those customers who don't really know what they are buying.

We are also now developing digital camera resolutions, which are really pointless for the vast majority of the non-pro users. I have 7 mega pixel Lumix camera, which is great for all my requirements. I could now buy one with much larger resolution but if this is hardly discernible by the naked eye whats's the point?

[OutdoorWebcams]

Wow! A 6-megapixel digital camera has about 2450x2450 pixel (if the image was square), so a 1200x digital zoom would result in an image 2x2 pixel wide - four dots of colors...

[thecoalman]

Be wary of these cameras that offer huge megapixel images that are dirt cheap, if you read the fine print the effective pixels is 1 or 2 megapixels. They use some fancy name for the resampling to get it to 12MP... yet another useless feature that again can be done with software on your computer and much better with really good software and techniques.

Also be wary of any still cameras with video features. If you want to take video buy a video camera, if you want to take stills buy a still camera. Neither performs both well. The cam I mentioned that have takes gorgeous video but you could buy a hundred dollar Kodak still camera that will take better still images. The video still cameras produce in general is very poor material to put on DVD, for editing or anything else. The only thing its suitable for is playback on a computer.

[BeeDeeDubbleU]

The only thing its suitable for is playback on a computer.

Is there another way? ;)

[thecoalman]

Well generally most people want to author to DVD for playback on a TV, if you want a compatible disc it has to meet the specs which are not all that flexible. The video on still cameras is usually 640x480, some also have an odd framerate of 15FPS but most new cameras allow for 30FPS . This has to be either scaled up or down to fit within the DVD spec resolution and the framerate adjusted to 29.97FPS for NTSC or if you really want to throw a wrench in the works if you live in an area where PAL is used 25FPS.

Any conversion of video results in loss of quality especially between compressed formats. Scaling video up in general gives poor results so you might be better off scaling down which results in loss of detail and this video on still cams is usually highly compressed which is really a PITA to edit just to add insult to injury.

One solutio to these problems is getting a DVD player that will play video burned as data discs, they'll accept different types of video like Divx or non-compliant MPEG burned directly to disc. If you wanted to maintain the highest quality Ideally you'd want to get a DVD player that can play the video directly however you won't be able to create nice menus and other things with a disc like that.

[MatthewHSE]

Hey BeeDeeDubbleU, does your Lumix really take pretty good pictures? I tried a 7mp Lumix ultra-zoom about two years ago and the noise was intolerable. I returned it and bought a Kodak z612, which has virtually no noise, fringing, jpg artifacts, etc. However, it's definitely in the point-and-shoot class and I'm not terribly satisfied with some of its features (like the lack of decent add-on lenses). I'd be interested to hear about your experiences with your Lumix.

Regarding the digital zoom on camcorders, I was mainly just curious to know how they expected to get a decent image with 800x zoom. It appears they don't, but it then it *does* look like a good spec to the uninformed consumer! ;)