I'm unclear as to why, when people post comparison videos that have been done to highlight differences between cameras, or simply to show the quality of one particular camera, that the bit rate often used is relatively low.
For example: in this post: http://www.dvxuser.com/V6/showthread.php?t=216018 (when you follow the links to the video), the size of the two videos are:
1. 152 MB, 3:53
2. 93 MB, 2:23
I haven't downloaded these videos to check the actual data rate (I have a slow connection speed, and my machine can't play 1080p anyway), so I calculated the bit-rate, neglecting the audio component. Result? About 5.2 Mbps.
This is just one example. I have come across quite a few others. I'd be surprised if a bit-rate of 5.2 Mbps for a 1920 x 1080 moving image results in anything other than mediocrity, no matter how high the original bit-rate. Correct me if I'm wrong.
I don't follow the reasoning for using such a low bit-rate when making comparisons available. File size comes into it of course, but surely it would be better to have a shorter comparison at a higher bit-rate (if file-size limited) so that you introduce the least number of additional artifacts as possible.
And in a related vein: do people do the same when they transfer to a final medium? i.e. users of the GH13 camera seem quite keen on using high bit-rate for capturing video (obviously) but when it comes to the final product (whatever that is for each person) are they still concerned about quality, or does quality become of lesser concern in preference to small file size?
BluRay has a maximum data rata of about 40 Mbps, all up. I'm interested to find out if anyone out there -- especially those who are keen on the high bit-rates that the GH13 allows -- actually uses high bit-rates approaching that speed for final product.
In a different world: if I was comparing microphones, I wouldn't want to compare 32 kbps stereo mpeg recordings. I'd want to compare recordings at a high a bit-rate as possible, preferably uncompressed.
For example: in this post: http://www.dvxuser.com/V6/showthread.php?t=216018 (when you follow the links to the video), the size of the two videos are:
1. 152 MB, 3:53
2. 93 MB, 2:23
I haven't downloaded these videos to check the actual data rate (I have a slow connection speed, and my machine can't play 1080p anyway), so I calculated the bit-rate, neglecting the audio component. Result? About 5.2 Mbps.
This is just one example. I have come across quite a few others. I'd be surprised if a bit-rate of 5.2 Mbps for a 1920 x 1080 moving image results in anything other than mediocrity, no matter how high the original bit-rate. Correct me if I'm wrong.
I don't follow the reasoning for using such a low bit-rate when making comparisons available. File size comes into it of course, but surely it would be better to have a shorter comparison at a higher bit-rate (if file-size limited) so that you introduce the least number of additional artifacts as possible.
And in a related vein: do people do the same when they transfer to a final medium? i.e. users of the GH13 camera seem quite keen on using high bit-rate for capturing video (obviously) but when it comes to the final product (whatever that is for each person) are they still concerned about quality, or does quality become of lesser concern in preference to small file size?
BluRay has a maximum data rata of about 40 Mbps, all up. I'm interested to find out if anyone out there -- especially those who are keen on the high bit-rates that the GH13 allows -- actually uses high bit-rates approaching that speed for final product.
In a different world: if I was comparing microphones, I wouldn't want to compare 32 kbps stereo mpeg recordings. I'd want to compare recordings at a high a bit-rate as possible, preferably uncompressed.