DVX owner needed to answer my stupid question

A

AndrewDavis

Member
Ok, so if I shoot a scene with an interlaced camera and the same scene with the DVX in progressive mode I will have roughly 2 times the resolution with the DVX footage if the other footage gets deinterlaced in post?
 
Re: DVX owner needed to answer my stupid question

Yep. Even without de-interlacing the DVX will have 50% more res, so after de-interlacing you'll be looking at somewhere around twice as much res on the DVX progressive vs. the interlaced footage (even if the interlaced and post-de-interlaced footage was also shot on a DVX!)
 
Re: DVX owner needed to answer my stupid question

So you are saying the DVX has 2 times the res of a VX2100 even when both cams are in interlaced mode? Confused here..
 
Re: DVX owner needed to answer my stupid question

In interlace mode? not exactly. In interlace, the cameras would be capturing roughly the same amount of resolution. Progressive scan is where the DVX shines. the reason that there is twice the resolution is becuase on an interlaced camera, only one field is being captured at any one moment in time. On a progressive scan camera, both fields are captured at the exact same moment, or in other words a full frame. A full frame of interlaced video is different, as the frame is consisting of two different moments in time.
Now, if nothing moves in the image (like that ever happens) then a progressive scan camera and an interlaced camera still frame will look very similar. But once things start moving progressive scan maintains the full frames, while interlaced cameras will start to show a combing effect, where the fields do not match up because of the time difference.
The other advantage of progressive scan is that it doesn't look like interlace video :). Some people like it, some do not, this is more subjective than anything.
 
Re: DVX owner needed to answer my stupid question

[quote author=scharky link=board=Offtopic;num=1107236612;start=0#3 date=02/01/05 at 00:21:57]Now, if nothing moves in the image (like that ever happens) then a progressive scan camera and an interlaced camera still frame will look very similar.[/quote]
Well, no, it's more than that even. Interlaced cameras have to blur their footage between fields, losing resolution, to combat interline flicker. So an interlaced camera, at most, offers about 360 lines of res. Even the FX1/Z1, which record 1080 lines, only deliver about 775 lines of usable resolution. Whereas a progressive-scan camera can deliver the full resolution of the full frame, each and every frame.

So, back to the VX2100: you're starting with about 360 lines, which you will then field-blend/combine to "simulate" 24p, leaving you with maybe 240 distinct, discernable lines. Whereas the DVX or XL2 will be pumping out a full 480 lines. That's where you get twice the res.

In interlaced mode the DVX does the same interlace-artifact filter the other cameras do, and delivers about 360 lines of res.
 
Re: DVX owner needed to answer my stupid question

right as usual Barry, I didn't even think about that.
 
Re: DVX owner needed to answer my stupid question

Ok so what is all the fuss about the HDV camera? If you deinterlace the HDV footage you end up with about the same res as the DVX progressive footage. Right?
 
Re: DVX owner needed to answer my stupid question

No.  Using Barry's approximation of deinterlaced 1080i, you're looking at 770-800 lines v. 480.

In HD.
 
Re: DVX owner needed to answer my stupid question

The interlaced version carries about 775 lines... once you de-interlace that, you'd be, yes, about the same vertical resolution as DVX/XL2 progressive footage. However, you'd still have twice the horizontal resolution from your HDV footage.

Why the fuss over HDV? For those shooting interlaced, it's great. For those who want to make filmlike footage, the current Sony interlaced cameras are just the wrong tools, and as soon as Panasonic and JVC announce their 24P DVCPRO-HD and HDV cameras, I think a lot of this confusion will go away.
 
Re: DVX owner needed to answer my stupid question

Barry, am I understanding you to say that deinterlaced 1080i – all other things being equal – has about the same or even less vertical resolution as 480p?
 
Re: DVX owner needed to answer my stupid question

I believe it has slightly more than 480p but nothing very drastic. This is, of course, in the cameras ability to actually resolve details. I'm not sure what the actual pixel count would be.

I think part of the problem is that the FX1, Z1 uprez the footage to get 1080 from 1440 (I think).
 
Re: DVX owner needed to answer my stupid question

David, yes, that's what I'm saying. HDV delivers about 775 lines of res. Cut that in half by de-interlacing, and you'll have about 390, vs. 480 on the XL2/DVX 24p or 30p.

It'll still have twice the horizontal resolution, yes, but less vertical resolution.

The best de-interlace you'll get is CF25/CF30, which appears to deliver a full raw field, and puts out about 575 lines. That's about equivalent to PAL DVX/XL2 footage at 25p (but the FX1 will still have twice the horizontal).

Shaw, the "up-rez" it does is from 1440 up to 1920. The 1080 is 1080, but because it's interlaced there's field-blending going on to reduce flicker, and that cuts resolution. If someone were to make a 1080/24p or 1080/25p HDV camera (which would violate the HDV spec, but hey, so does 24p on the DVX) then they could get a full 1080 lines of resolution. But in interlaced, no, about 800 lines maximum, and de-interlacing that cuts it in half.

As for the 1440 uprez thing, HDV records 1440 samples per line, but HD is not 1440, it's 1920, so the 1440 gets up-rezzed by 33%, from 1440 up to 1920. HDCAM does the same thing, it records 1440x1080 and up-rezzes on playback to 1920x1080. DVCPRO-HD also does the same thing, but instead of up-rezzing by 33%, it up-rezzes by 50%: it converts 1280x1080 to 1920x1080, and 960x720 up to 1280x720.
 
Re: DVX owner needed to answer my stupid question

Just to spice things up, Barry's tag should be changed to DVXuser Pundit.
 
Re: DVX owner needed to answer my stupid question

Pundit is associated with politics. Are you tryin' to get us kicked outta here, TC?
 
Re: DVX owner needed to answer my stupid question

HAH! Sorry! I was at work when we were talking earlier, and on my way home I was apparently being accused of herecy.

It was more a jab at the fact that Barry has so much knowledge he is able to transcend any sort of naming convention.
 
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