HVX200 1080p?

T

Taras

Member
Hoping one of you guys can explain the workings of the HVX200 1080p setting for me.

My question is that for a standard 1080i camera with interlaced chip the following is true. Due to the interlace of the chip the scan is in fact a 2:1 ratio which equates to 540 lines being scanned at any one time. Therefore the format is really 1920 (or 1440 on most chips) x 540. When the interlaced picture is played back the interlaced distortion artifacts actaully results in the image being seen as around 700 actual lines (due to Kell Factor). Therefore the end result is really 1920 x 320ish.
This is why the 720p picture is far superior compared with the 1080i picture (and why NASA etc use 720p).

What I am unclear of though, is that the HVX200 chip is in fact 1080p which is then converted into a interlaced signal, which means does it not, that each line of scan is in effect taken at the same moment in time (unlike an interlaced chip). Does this therefore mean that you can convert it back to a 1080p format without any of the issues outlined above (ie: Kell Factor etc.) . Can someone please confirm if this is the case?
 
The chips on the HVX are progressive. Everything starts at 1080 rez and is scanned progressively and then cross or down converted to the chosen recording format from there.

1080 originally being an interlaced codec, the HVX just uses regular 3:2 pulldown or advanced pulldown to make 24 go into 60. Everything is still progressive, it is originally scanned progressively, and it ends up true progressive in the end as well.

It's the same thing the DVX did. MiniDV being a 60i deal, so it just used pulldown to make things work right. 60i is the basket. 24p is what's inside.

Trying to summarize. It is scanned one full frame at a time. Progressive. If your NLE is properly equipped (most are), then you just start editing in a 24p project setting, and you finish to your final delivery. Be it pure 24p, or 60i with pulldown added for SD broadcast, or 29.97 with pulldown flags for DVD, etc, etc

Jason
 
As Jason said, it operates internally at 1080/60p (or, really, any frame rate up to 60p). To make 1080/60i, it slices its progressive frames into fields, and combines alternate fields to make interlaced "frames."
 
Would you go for it, Barry - or go RED?

I'm actually tempted to go Hydra. After comparing screen grabs from an HVX to some from RED on cinematography.com there really seem to be diminishing returns on a more expensive cam. I mean...it's not THAT much better than an HVX for $30K more.
 
when shooting 1080p60 is possible with hydra,
could a firmwareupdate give us this possibility, too?

______
videoatonale
 
No, because it would mean having to come up with an entirely new compression system; there is no 1080/60p recording format in existence. It will only be possible through the Hydra.
 
You must log in or register to reply here.
Back
Top