View Full Version : HPX250: AVC-I 50 vs AVC-I 100 quality issues
brynsank
03-16-2012, 09:31 AM
I have found that the difference between the AVC-I 50 and AVC-I 100 in terms of overall picture quality is much more pronounced than I expected. I can't really say I'm overly impressed with either to be completely honest (which I think is more testament to the lens than anything else), but the AVC-I 50 seems particularly muddy and soft. I can only assume it is due to the pixel aspect ratio, but I'm surprised given that the DVCPRO HD coming from the HVX-200 used the same kind of pixel stretch but didn't seem to suffer the same fate. Has anyone else had an issue with this?
digitalgecko
03-16-2012, 10:43 AM
I have shot both 50 and 100 with my HPX250 and found the images very sharp and quite beautiful. I have also shot with the XF305 in the same theater and have found the 250 image just as good if not better. Now I would prefer a parfocal lens with physical stops, but I find the HPX250's image is hard to beat in this class of camcorders. You camera may have other issues, but I don't believe a codec can cause muddiness or softness. Maybe Barry will chime in.
jpmulligan
03-17-2012, 10:33 AM
There is no pixel aspect ratio / stretch on the HPX250, it is a full raster 1080P sensor. The HVX indeed did that, but not the 250
Barry_Green
03-17-2012, 05:10 PM
The AVC-I 50 codec does stretch the pixel aspect ratio when recording. It records 1440x1080 or 960x720.
male_man
03-18-2012, 11:56 AM
@Bryant...What is the data rate of your uploaded files and what nle are you using?
male_man
03-19-2012, 02:07 AM
Barry, why does some footage as reported look outstanding, but then some footage looks like mud with the hpx250?
brynsank
03-19-2012, 01:26 PM
It is certainly possible that my camera has issues not typical to other HPX250s given that it doesn't sound like others are experiencing the same thing. However there is a definite difference between the AVC-I 50 and 100 that comes out of mine. I've done numerous tests on set where I'll record samples of both under identical lighting in order to compare, and it's pretty clear.
@jpmulligan - there is no pixel stretch when recording AVC-I 100, but as Barry mentioned there is a 1.3x pixel stretch in AVC-I 50 mode. Same as the HVX200.
Barry_Green
03-19-2012, 01:39 PM
Barry, why does some footage as reported look outstanding, but then some footage looks like mud with the hpx250?
Haven't seen the issues myself. The codec is absolutely rock solid and has been shipping for years. But as always, the person behind the camera can make a world of difference on how the footage looks like on the recording, and it depends on what you shot, what your settings were, what you edit it in, all sorts of things...
videoatlanta
03-20-2012, 02:18 PM
You should not being seeing any kind of huge diff. between AVCi50 and AVCi100.