PROGRESSIVE vs. INTERLACED ??

[George D.]

Why is progressive considered better than interlaced ? And, exactly what is the difference ?

Do you have a choice between the two with a RED-One and Scarlet ?

Thanks.

 

[michael zaletel]

Progressive is not really "better" than interlaced. Progressive just means that each frame is whole and complete on its own like a still photo whereas Interlaced footage consists of frames that only contain half of the rows (every other row, odd then even) but have twice as many frames as progressive footage for same frame rate which results in smoother motion. It is possible to shoot RED or SCARLET at 60 frames per second progressive (360 shutter I think) and then convert to 60i in post in order to meet the requirements of some broadcasters and networks.

-michael zaletel

 

[George D.]

Progressive is not really "better" than interlaced. Progressive just means that each frame is whole and complete on its own like a still photo whereas Interlaced footage consists of frames that only contain half of the rows (every other row, odd then even) but have twice as many frames as progressive footage for same frame rate which results in smoother motion. It is possible to shoot RED or SCARLET at 60 frames per second progressive (360 shutter I think) and then convert to 60i in post in order to meet the requirements of some broadcasters and networks.

-michael zaletel

Thanks Michael.

Are you telling me that according to your knowledge, television "prefers" interlaced over progressive ? Since we shoot principally for TV that is a factor we must consider.

And, since most of our shooting will be done with the RED-One in 2K, how will that factor in ?

Thanks.

 

[Stuart English]

P or I

P or I

Interlace was introduced as a way of reducing the bandwidth needed to transmit television images - a decision that is more than 70 years old.

With a video codec like H.264 you can easily transmit the same frame rate in progressive as broadcasters now do using MPEG-2 and interlace.


If you read recent broadcast equipment magazines, you will see that many high end HD camera and image processing systems support 1080 @ 60P.

The P to I conversion is assumed to be performed (if needed) immediately prior to the transmitter.

 

[George D.]

Interlace was introduced as a way of reducing the bandwidth needed to transmit television images - a decision that is more than 70 years old.

With a video codec like H.264 you can easily transmit the same frame rate in progressive as broadcasters now do using MPEG-2 and interlace.


If you read recent broadcast equipment magazines, you will see that many high end HD camera and image processing systems support 1080 @ 60P.

The P to I conversion is assumed to be performed (if needed) immediately prior to the transmitter.

Thanks Stuart,

I understand better now. What about support at 1080 @ 30P ??

My interest is because we will be shooting in 2K with the RED-One on wildlife for television production.

Thanks.

 

[Stuart English]

What to shoot.

What to shoot.

Personally I hate 30P. It's neither fish nor fowl, neither "filmic" or "fluid"

So I'd recommend that you shoot 24P or 60P (25P or 50P in Europe)

 

[Thomas Wright]

900R's and so on used PsF which is P going through an I system. Apparently 720p is more pleasing on the eye than 1080i, which irked sony no doubt cos they were pushing for that format. the wee JVC shoots 720p but most wee sony's only do 1080i, it stands to reason that p is the part that is more desirable rather than the number of lines. A golf ball flying across a screen seems to blip across the fields in I systems so if you have fast moving birds or some such like I'd go 50/60p.

I suppose

 

[jbeale]

1080p60 now a consumer format also

1080p60 now a consumer format also

The tiny Panasonic TM700 (under $1000) does 1080p at 60 fps. The video quality is the best I've seen in that price range. Unfortunately most Blu-Ray players don't yet support 1080p60 material, although HDMI and HDTVs can handle it.

 

[Thomas Wright]

That does look cool, do you have any footage to post?

Blue ray was sony innit

 

[James Brundige]

Thanks Michael.

Are you telling me that according to your knowledge, television "prefers" interlaced over progressive ? Since we shoot principally for TV that is a factor we must consider.

And, since most of our shooting will be done with the RED-One in 2K, how will that factor in ?

Thanks.

It completely depends on the broadcaster. I finish in 1080i, because that's the PBS standard. Discovery (and parent ABC) is 720p. And of course the satellite and cable folks are various compression schemes, both interlaced and progressive. It's kind of a nightmare, though some folks think it will eventually resolve to 1080p for everybody.

 

[Tim Hole]

Thanks Stuart,

I understand better now. What about support at 1080 @ 30P ??

My interest is because we will be shooting in 2K with the RED-One on wildlife for television production.

Thanks.

Its always recommended to look at the channel, companies acceptable formats. It also depends whether it is comission based, in house post etc... channels or networks always publish this information for independents.

Also if there is any effects to be done, always shoot progressive. Tracking, keying and most visual effects work is a bitch with interlaced and don't be fooled into thinking interlaced can just be converted into a picture sequence like some people do...it is'nt the same thing.

 

[Rob Ruffo]

Progressive is not really "better" than interlaced. Progressive just means that each frame is whole and complete on its own like a still photo whereas Interlaced footage consists of frames that only contain half of the rows (every other row, odd then even) but have twice as many frames as progressive footage for same frame rate which results in smoother motion. It is possible to shoot RED or SCARLET at 60 frames per second progressive (360 shutter I think) and then convert to 60i in post in order to meet the requirements of some broadcasters and networks.

-michael zaletel

NO NO NO!!!!!!!!!

A progressive dsiplay, like a plasma or LCD or DLP TV which comprised 99% of HDTVs out there cannot display 60i. they will blend those frames into 30P with comb-effects.

 

[George D.]

NO NO NO!!!!!!!!!

A progressive dsiplay, like a plasma or LCD or DLP TV which comprised 99% of HDTVs out there cannot display 60i. they will blend those frames into 30P with comb-effects.

THAT can't be true. If it is, why is it that National Geographic Television will ONLY use 1080i in their productions? And, that is one company that is ALWAYS on top of their game.

 

[Stuart English]

Progressive or Interlace.

Progressive or Interlace.

What LCD or Plasma displays do to a 1080i or 480i signal is model dependent. Some will convert to 30p some to 60p, some to 120p...

As that technicality is out of your control though, the only relevant question is what acquisition format provides maximum quality.

We concluded the answer is progressive, as you can always dub to 1080i or 480i if that is the network's required delivery format.

 

[Terry VerHaar]

THAT can't be true. If it is, why is it that National Geographic Television will ONLY use 1080i in their productions? And, that is one company that is ALWAYS on top of their game.

My own guess is that, when this 1080i standard was set, there were only two practical means of delivering HD - 720p or 1080i. And a lot of televisions and all (?) broadcasts were still interlaced because it was before the digital switchover.

Regardless of this or NatGeo, I don't know anyone who wouldn't agree that progressive is simply better than interlaced. But I may be wrong on any or all of this. :001_cool:

EDIT: In fact, upon reflection, I believe that it is still a "broadcast thing" that there is only 720p or 1080i; no 1080p.

 

[H. Farberg]

European Broadcasting Union did tests and concluded that for 1080i50 to look as good as 720p50 it had to use 20% more bandwidth. Now, I don't know the testing methodology or anything, but that is their conclusion.

 

[Stuart English]

HD formats

HD formats

When the 1080i standard was set there was only one practical method of delivering HD - NHK's 1135 line interlace system.

So yes that was well digital broadcasting / compression and well before flat panel TV displays came along.

For over-the-air broadcasts 720p and 1080i are the only two HD format, but some satellite and cable services offer 1080p programming.

This may be because broadcast is locked into MPEG-2, while satellite / cable is free to leverage the more efficient MPEG-4 compression.

 

[Stefan Christou]

There are a number of reasons why progressive presents better image quality than interlaced. Basically because interlacing presents combing in high velocity objects, twitter in horizontal lines that are between fields and gives lower spacial resolution at a given picture size. Hence 720p actually resolves more detail than 1080i.

The advantage of 1080i however is that it uses less bandwidth than 720p at a given framerate.

If you don't believe me google it!

 

[Stuart English]

Bottom line is 720p and 1080i are both techniques to reduce the size of the data prior to compression and broadcast.

At acquisition is shoot for maximum quality - 1920 x 1080 progressive - or a larger frame size such as 3840 x 2160 progressive.

 

[David Mullen ASC]

The crude answer is that the progressive-scan look, regardless of its other merits, is similar to the look of film, which is also a "progressive scan" system in that it captures whole frames at a time, whereas interlaced-scan photography (not broadcast which is a separate issue since film material is shown all the time in interlaced-scan broadcast) looks unique to video.

So there has been a rough division that narrative fiction is more likely to choose progressive and "reality" (news, sports, etc.) is more likely to choose interlaced-scan as a shooting format. But this has been muddled ever since video cameras started offering progressive-scan as an option... I've seen some cooking shows, for example, shot at 24P that look more like they were shot on film than video.

The trouble with 30P over 60i is that with only 30 motion samples per second, it's harder to make smooth conversions to 24 fps (for film-out) or 25 fps / 50i (for European broadcast). Not impossible, just harder. 30P is really 60 Hz television systems centric, or for web only. These days, you want to make sure your material is sellable worldwide and some European broadcasters loathe 30P conversions.