Originally Posted by
erp2863
You are correct that compression rates do mean everything, but you should be careful to not relate this directly to image quality. You can use compression without high losses in quality.
Of course. All consumer and prosumer video is compressed -- it has to be. However, the extent of compression is directly related to video quality. The more compression, the more information is lost, and the more artifacts will result.
The video quality of cheap cams has more to do with the optics and sensor used than it does the compression method. The compression method is utilized so that the recording media (SD cards or internal SSD) can be used while providing enough recording time.
Well, that's what I said. However, high compression is used for the same reason that cheap glass is used -- because it's inexpensive and the assumption is that consumers won't care. There are solid-state professional digicams that have both low compression rates and excellent glass.
I'm not sure you or I know this to be true or not. We can agree that it absolutely uses the full pixel count for still images. But, in my line of work we use liquid cooled CCD's that have sensitivity to DUV. The sensor has ~1000x1000 pixels. Instead of analyzing the raw pixel data, we use an averaging algorithm that takes the average value of a 3x3 array of pixels and uses that average for the middle pixel. If digi-cam makers didn't do something similar I'd be surprised as it is a very simple software implementation.
That's sub-sampling. To my knowledge, only prosumer camcorders subsample.
As was stated in previous posts, it was already known that it was not "true" HD. But let me know when you find a miniDV camcorder that is ~$100 and you can upload the video clips to your PC in a matter of seconds that still look good on your big screen TV.
I have a miniDV-based camcorder that is $600 and produces HD video so good it is used for B-roll in professional productions.