Camcorder Image Quality at Full Zoom

[Alan Henderson]

I have a Panasonic TM700 and my only gripe is the quality of the video at full zoom.

Is this pretty much the norm with sub $1500 camcorders or are there any that have very good image quality at full zoom?

Thanks...Alan

[Dave Blackhurst]

When you say "full zoom", I'm guessing you mean the maximum the camera is capable of? IOW, you're probably well into the "digital zoom", where yep, you'll see the image degrade, sometimes quite a bit at the "marketing" zooms (the ones that are like 100x+!).

There is an OPTICAL zoom (probably in the 10X range) which is the range provided by physical lenses in the camera, and generally that should be fairly good if the lens block is well designed/manufactured.

But since "10X" doesn't sound terribly impressive, most cameras have a DIGITAL zoom... this is of varying quality... from experience, you MAY be able to still get acceptable quality at say "20X" - effectively "digital doubling" that may be able to use additional pixels from the sensor or some other means of interpolating the additional information to create something from nothing (the cameras electronics have to create the same # of pixels from a smaller area of the sensor). Past that, you're going to see the image degrade further and further as the guts of the camera strain to produce more "something from nothing" that one can reasonably expect!

I know we see crazy zoom capabilities on crime shows and such, and there are military cameras capable of zooming in on a part of a large sensor array... but on a consumer camera, the sensor is only so big, and electronics can only provide so much additional "enhancement".

What you'll find from pros here, is most just leave the camera in OPTICAL and turn off digital zoom completely! I tend to leave the additional range on, and watch the zoom indicator on the camera VERY carefully so as to not have TOO degraded an image, but have the extra range available "on the fly" if needed.

Probably more than you wantd to know, but hopefully it'll help you understand what's going on with your camera!

[Mike Beckett]

My Sony NX70 had degraded image quality at higher zoom settings, and it was a single small sensor with a small (37mm filter) lens. I'm talking optical zoom here, I wouldn't touch digital zoom with a 10' bargepole.

It gave pretty good images at wide angle, mostly sharp with no chromatic aberration. But once you got around 50% of the way on a full zoom, the quality would drop off, with CA appearing and some softness. Not everyone will notice it, but it really annoyed me.

My Panasonic AC130 has 3 chips, CA correction and a nice 72mm lens, and I'm delighted with the vast increase in image quality at full 620mm zoom, perfectly sharp and in focus from corner to corner. But the NX70 was based on a sub-$1000 consumer camcorder, and the AC130 costs four times that!