PTravel,
Your expansion on the topic could be beneficial for someone wanting to dig deep into how video is recorded, but I must point out some points that should be clarified:
Originally Posted by
PTravel
Compression rate means everything. The high compression rates needed for inexpensive consumer solid-state HD means that image will be poor and won't really look like HD.
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. 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.
Originally Posted by
PTravel
Not necessarily and, in fact, for low-cost consumer machines it is highly unlikely that it does sub-sampling. More than likely, the higher pixel count is so that it can do still imaging. For video, it will use a section of the sensor.
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.
Originally Posted by
PTravel
Indeed, higher pixel counts (counts above the frame resolution) are undesirable because the smaller pixels are less light sensitive and dramatically degrade low-light performance.
Um, no. That's not right, sorry.
This has nothing to do with sensor refresh rates.
I was not inferring that refresh rates of CCD's and frame rates of video are one in the same. But you can improve sensitivity and noise by using averaging.
Originally Posted by
PTravel
It is HD in that it conforms to the spec. It is of substantially lower quality, however, than BluRay DVDs, ATSC broadcast HD, HDV or ACVHD machines. It is also lower quality than good consumer and prosumer standard definition miniDV camcorders.
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.
Originally Posted by
PTravel
Well sure, at such a low data bandwidth far less power is required to edit.
Exactly what I was getting at in that post.