Best Picture Quality: 24P or 24P Advanced?

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Guest
In a side by side comparison, which progressive scan shooting would provide the highest resolution/highest quality image--24P Mode or 24P advanced?

The DVX100 camera user's manual says that picture quality deterioration occurs in the 24P mode when editing, but not as much in the advanced mode. I just wanted to know what that really means to the viewer using a critical eye. :)
 
Re: Best Picture Quality: 24P or 24P Advanced?

When you record to tape, both modes will be of identical quality (provided you set the settings the same... the preset F5 has 24PN, but THICK line detail, the preset for F6 has 24PA but THIN line detail)... so if you set everything the same, but the only difference is the recording sequence, then the visual quality of the recording will be identical.

If you edit on a 60i timeline, the performance will also be identical (with the exception being the slightly different motion rendering of 24PA vs. 24P). The resolution, etc. will be identical.

If you edit on a 24P timeline, that's where a slight difference in quality will occur. 24PN must be decompressed and then, when making your final output tape, recompressed -- and it is this decompress/recompress cycle ("generation loss") that causes the quality hit. 24PA can be directly edited in a 24-frame timeline with no decompression or recompression necessary.

How big of a difference does it make? Probably nobody will ever notice, but there could be an overall very slight softening of the picture. If you plan on editing your footage in a 24P environment (meaning Vegas 4.0, Blade 2.2 or FCP 4) then you should go ahead and shoot 24PA all the time.

If you're editing in a 60i timeline, use 24PN because the motion rendering is a bit smoother and the overall quality will be identical.
 
Re: Best Picture Quality: 24P or 24P Advanced?

Thanks for that very clear explanation! (I am assuming it is correct, of course). I have seen several different articles attempting to describe the difference and from a practical (end user) point of view, this is the best I have seen yet.
 
Re: Best Picture Quality: 24P or 24P Advanced?

Barry you may know more about this than others but your reply is the first I've heard about a "generational" loss from recompressing 24pN footage. Vegas, at least, seems to address the cadence differences in the 2:3 vs. 2:3:3:2 pulldowns equally. My understanding of the "advantage" of shooting 24pA was (slightly) less rendering time. But even SonicFoundry recommends final render using the 2:3 pulldown (24pN) if outputting to tape. And for me, 24pN is ultimately much more watchable on a standard NTSC television set than 24pA.
 
Re: Best Picture Quality: 24P or 24P Advanced?

For both 24P modes, four frames are recorded as five frames on tape.

In 24P Advanced, that sequence is written out as four distinct original frames, plus one "blended" frame. So a 24P-savvy editing program can simply ignore the blended frame, and work on the original frames as originally intended, with no uncompression or manipulation necessary.

In 24P Normal, such is not the case. The 5-frame group is made up of three "whole" frames and two "split" frames. So to recover the original four progressive frames, the editor must uncompress the five-frame group, un-split the frames, and then re-compress at the completion of editing. That's where the generation loss comes in.

Now, it should be pointed out that if you're going back to NTSC, inserting 3:2 pulldown, then the 24P Advanced footage will ALSO go through the recompression process! 24PA only maintains its advantage if you're finishing in a 24P environment (meaning, a 24P DVD, or a 24P .mov or .avi, or a film transfer). Any time you drop back to 60i, you lose the quality advantage that you gained by shooting in 24PA.

For direct-to-NTSC work (like TV commercials, finishing on BetaSP or VHS or whatever) I normally shoot 24P Normal and edit in a 60i timeline. 24PA is best suited for potential DVD release, CD-ROM, or film transfer.
 
Re: Best Picture Quality: 24P or 24P Advanced?

Let me recap:

PRODUCTION:
ALWAYS shoot in 24PA (advanced) as u will not loose information (i.e. quality) when downloading into a 24P savvy NLE (like Vegas or Xpress Pro).

POST:
Export/Render as 24PA for: Film, 24P DVD, 24P .mov or .avi
Export/Render as 24P for: TV, VHS or any NTS/PAL work

If u wish you can do straight 24P in Production & Post if ur final output is for 24P but Production in 24PA will never hurt if u use a 24P savvy NLE.
Right?

8) my first posting!
 
Re: Best Picture Quality: 24P or 24P Advanced?

Welcome Rod&Tod (did I catch your magic show at Ceasars?:) )

I think the only things that understand 24PA are the DVX100 and some NLE's.

Therefore - I would assume that any render to output should by default be 24PNormal.  DVD players won't understand the Advanced pulldown.

Working in the NLE in 24PA is supposed to be the most efficient (I am told).

The only part I am not sure about is if film transfer houses can understand the 24PA.  In general - give the transfer folks what they specify for best results - talk with them.
 
Re: Best Picture Quality: 24P or 24P Advanced?

Current status has changed to:

PRODUCTION:
ALWAYS shoot in 24PA (advanced) as u will not loose information (i.e. quality) when downloading into a 24PA savvy NLE (like Vegas or Xpress Pro).

POST:
Export/Render as 24PA for: Film (check first with transfer house!), 24P .mov or .avi
Export/Render as 24P for: 24P DVD, TV, VHS or any NTS/PAL work

If u wish you can do straight 24P in Production & Post if ur final output is for 24P but Production in 24PA will never hurt if u use a 24PA savvy NLE as it is supposed to faster.

Any other ideas or suggestions?
 
Re: Best Picture Quality: 24P or 24P Advanced?

Your new distillation is fine, but there are more twists available. For instance, if I wanted to do a slow motion scene, I would shoot in 30p. by importing this into a 24PA time line, (but not doing a pulldown on it), you immediately get a 25% slow mo with no velocity envelope work.
 
Re: Best Picture Quality: 24P or 24P Advanced?

Since no one is answering my question in the FCP section of this site, I decided to post here.

I have several projects shot using 24p NORMAL. I have FCP 4 and I am confused on which setting to use. I was told by someone that I DON"T have to remove any pulldowns in Normal mode, is this true?

Do I select DV NTSC 48khz for my sequence and capture presets? Since I didnt shoot with 24P ADVANCE, I don't have to remove the advance pull down correct and I can edit on a regular timeline oppose to a 24p timeline or no?

My final output will be to tape and DVD.
 
Re: Best Picture Quality: 24P or 24P Advanced?

FCP 4 has the option of using either the 3:2 pulldown or the 2:3:3:2 pulldown. It is either in the log and capture window or the user preferences window.
 
Re: Best Picture Quality: 24P or 24P Advanced?

Hello
Which is the best to go to Pal 24 pn or 24 p Advanced???
and which is the best way to do that?? Merci. Jose
 
Re: Best Picture Quality: 24P or 24P Advanced?

I'm curious about something. Everyone always says "choose: DVD or 60i", meaning that you should shoot and edit via a certain workflow depending on what your final output will be. However, a lot of what I shoot is destined for broadcast, BUT I ultimately plan to archive my work on DVD (for demo reel, etc.).

So some questions arise:
How should I shoot and what workflow should I edit in?
(i.e. if I edit in 24PA for DVD, but then want to output to tape for broadcast, do I have to re-edit in a 60i timeline or re-render my edit?)
What are the trade-offs of working in one workflow compared to the other? (Will I suffer image or aesthetic quality (motion, artifacts, etc.) if I, for instance, shoot/edit for DVD output (24PA) and then want to broadcast on TV?)

Thanks.
 
Re: Best Picture Quality: 24P or 24P Advanced?

The only reason there's even a question here, is because DVD players can play native 24P material. You can encode your project in a 24P MPEG-2 file, and the DVD player will automatically add pulldown upon playback. This gives you the advantage of being able to use a lower compression ratio (or, alternatively, to fit 20% more material on your DVD).

No matter what you choose, no re-editing is involved. You can easily make a 60i version from your 24P timeline. There's only a matter of a tiny quality difference... if you edit your 24PA source in a 24P timeline, then you'll get the best possible quality for DVD, and a tiny little quality hit when you go out to 60i (for your VHS, but hey, recording in VHS involves a massive quality hit, so nobody will ever know!)

If you're shooting with the idea of a 24P DVD in mind, then 24PA is the best way to go. If you're shooting with a VHS master in mind, then 24P is a fine way to go, and you could still make a 24P DVD (although incurring the same tiny quality hit).

In the end, it really doesn't make a substantial difference which method you choose.
 
Re: Best Picture Quality: 24P or 24P Advanced?

Barry, I assume that by "tiny quality hit", you mean the added fields to go from 24p to 60i?  Is that really considered a quality hit at all?
 
Re: Best Picture Quality: 24P or 24P Advanced?

It adds fields AND THEN RECOMPRESSES the DV stream. It is the recompression that causes the quality hit (which may be virtually unnoticeable).

Really, it's all kind of academic, the differences between the modes are very minor.
 
Re: Best Picture Quality: 24P or 24P Advanced?

I was under the impression that most respectable NLEs were designed to not recompress, and just worked in its native DV codec (whatever in may be) to avoid recompression artifacts. As an example, although not an NLE but a converter, DVFilm Maker promises no recompression when converting 60i<->24p. OK! So DVFilm Maker is probably better considered just a "frame" dropper (24pA). But shouldn't a properly desined NLEs work on the same principal? Why recompress when going from 24p to 60i is simply considered adding existing fields?
 
Re: Best Picture Quality: 24P or 24P Advanced?

micheal p. -has made a valid and important point to me in the past on this subject, that should you happen to be editing uncompressed, they will both have identical reolutions., but unfotunately for us -flinstone- although most nles avoid recompression when and where they can. the process that barry is describing is one which must be done to convert dvx 24pn footage to a true 24p file (but not 24pa which is why dvfilmmaker does not have to recompress...and why 24pa was developed) unavoidably requires recompression if editing in native dv resolution. the difference in quality is only as noticeable as the difference between some straight footage, and the same footage after minute color correction.. its just a one generation loss. depending on what codec you are using to do the recompression the results can be completely negligible to completely unacceptable.

it would be worth anybodies time to take a look at some of the different codecs out there for dv, and see how they handle over multiple generations. if they will be adding mutiple generations to the dv stream during the editing process..adam wilt..(who else) has a great article on some of the differences you will find here..
http://www.adamwilt.com/pix-codecs.html
if you go to the links at the bottom of the page it has more dv codec experiments and such . of course these tests are older, and do not reflect current codecs, but it just goes to show that what one you use does matter if you are going through multiple generations, or even single generation rendering(such as converting 24pn to 60i in the dv realm).
in the end this issue is ALL "academic " and should not really be an issue, because .. if one plans on editing in 24p they should be shooting in 24pa to begin with, unless they can edit uncompressed. i can understand this issue being viable as a non "P.E.B.C.A.K." issue if the conversion to true 24p was found to be neccessary after the project was shot though. ..

bah... enough technical jargon..out with the cheeze whiz!!
 
You must log in or register to reply here.
Back
Top