30p

C

cgrosso74

Active member
I shoot a lot of broadcast commercials with the 100a. In fact 90% of what I shoot ends up on broadcast TV. The reason I bring this up is because I must admit I am a bit confused about 30P.

I shot a commercial today and my plan was to shoot 30p because we were going to slo-mo some of the shots (after reading how great 30p is for this). I read Barry's book where he talks about 30p looking interlaced on an NTSC monitor. So I wussed out and shot 60i (the client didn't want 24p) better safe than sorry.

So did I read wrong? If I shot 30p and these spots went to broadcast would they look bad on TV?
 
...no theyd look fine. id assume since you have access to a DVX and a TV you can run some simple tests to see what the results are.. essentially it looks alot like 60i only not quite as video like.

..anyway 30p only translates to slow motion when your converting it to a slower frame rate lie 24p. its not going toi give you slow motion on a 60i timeline. ...for that you ould want to shoot 60i and use field interpolating for slow motion to render out full frames from each 60i feild. ..or use feild blending to blend make new interlaced "frames" by blending adjacent fields from surrounding "frames".
 
Thanks....um....loser (well it is your name!)...

Yes, yes I could shoot tests with 30p...I just wasn't going to take a chance without knowing the outcome. You have given me hope, thanks!
 
cgrosso74 said:
II read Barry's book where he talks about 30p looking interlaced on an NTSC monitor.
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I have to agree. I've shot 30P before, and on my CRT reference monitor it looks interlaced (same as if I watched 60i on computer playback); very discernable with fast moving objects or pans. But on plasmas or computer playback, it's awesome.
 
Flintstone said:
I have to agree. I've shot 30P before, and on my CRT reference monitor it looks interlaced (same as if I watched 60i on computer playback); very discernable with fast moving objects or pans. But on plasmas or computer playback, it's awesome.
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Interesting, from this I would suppose that 30p is better for shooting when the final output will be on a computer vs. TV, if that is the case then I will have next to no use for 30p. I will have to shoot some tests.
 
30p looks fine on interlaced displays to me. Why don't you shoot some 30p stuff today and play it back on an interlaced set to see whether you like it or not?
 
I just finished a promotional video recorded in 30p and looks very nice in the computer monitor (part of the project was a cd-rom with the video inside). In the video monitor the image is good, but I can see some jagged lines when subject is moving, but I liked the overall result.

Ulisses
 
On any interlaced monitor your footage is going look interlaced becasue it is. Just becasue something is 24p or 30p, does not mean it will display as progressive on an interlaced TV. HOWEVER, the look of these is definatively different than 60i on an interlaced TV.

So in short, progressive scan footage on an interlaced TV will have interlace lines, but it will move differently than 60i. It will maintain the 24p/30p cadence but be reproduced as 60i on your TV. Hope this helps.
 
When I watch pro TV series (CSI, ER, etc) I can't see the jagged lines, and I'm pretty sure they are filmed at 24P or 30P. Maybe it is the more resolution being scaled down for TV (smoothing the edges) ?

Ulisses
 
I use 30P for nearly everything and I find it to be just great. If you play around with your shutter speeds a little it too will change the look a bit more... you might find something you like.
 
Ulisses;
It may be hidden better through the film stock, and yes, those shows are most likely shot at 24fps, on 16mm film, but when it gets to your NTSC interlaced television, you are seeing an interlaced signal. Most hollywood films are the same way, even though it is a 24p DVD you are still seing an interlaced signal when watching on an interlaced TV. However, there are certain films, especially very sharp and highly detailed films with lots of movement and deep Dof that will show these interlaced lines. In particular, if you watch the "matrix reloaded" the scene right after Neo talks with the Orical and has to fight the 100's of Smiths. If you look at the scene when they are walking up to Neo (before the fight) and the camera starts to circle around, you will see lots of interlaced lines, especially in the heads of the other smiths, if you are watching on an interlaced TV. I though of this example because I just watched the film the other day, and that was something I noticed right away. So it does happen, but becuase the DVX is so sharp, and the XL2 as well, this will be something that will be immediatly noticable in very sharp, high motion footage. On a progressive scan television or monitor this is not a problem.
 
I haven't noticed interlacing on Hollywood made 24p DVDs before! I'll pay closer attention next time.

Funny that I notice it on 30p, but not on 24p? :huh:
 
If by "interlaced" you mean a lot of aliasing (ie: jagged edges on diagonals) you should check whether you have v_detail on Thick or Thin. Thick will minimize the "jaggies".

Otherwise I haven't noticed 30P looking more "interlaced" than 60i.

Obivously this is an issue that we have tried to minimize on video for years. Most DVDs I watch these days exhibit a lot of aliasing on my 20", 500 line (rated) NTSC monitor. I'm sure because they are now optimizing the disks for Progressive Scan Playback rather than NTSC.

MR
 
What I described in the book was an attempt to explain why you would still occasionally see interlaced lines, even though you shot 30p (or 24p). It does happen, and the reason it happens is because the television is still an interlaced display, whether you're showing progressive or interlaced footage on it.

You can see these interlace lines in hollywood movies too, just look for a high-contrast vertical element (like a doorframe) -- panning past a doorframe, the whole door jamb will exhibit comb artifacts.

None of this is to say that 30p is bad for TV! 30p is fine for TV, as is 24p. But some people have assumed that when they play progressive footage on a television, that they'll never see interlace artifacts, and unfortunately that just isn't true -- an interlaced TV will show interlace artifacts from progressive footage. A progressive TV will make the progressive footage look magnificent.
 
The worst interlace combing artifact I have seen was because I mistakenly rendered 30p as interlaced. I didn't see it until I had burned the DVD and saw it on an interlaced TV. After re-rendering in progessive it was great.
 
Heck ever since I have gone progressive I will not shoot in anything less. You can always render your footage interlaced if for some strange reason you need to. But I always shoot progressive because it will give you superior stills and superior video quality over the interlaced option. Don't be afraid of progressive because it sounds so aggressive! It is Progress over interlaced video, hence progressive is the way to go! Now if they could just up the resolution..... (just me being silly)

So everybody re-program your F1 to 30p or 25p. And flip your camera to only re-programmed f1 or f5 or f6 and never look back at the standard f1-f4 settings. In fact set up F2 and F3 for progressive shooting with some wild settings for effect.

Show people how your footage looks 100% better than your competition. I garantee if you have just an ounce of talent they will like your footage better than those other guys shooting interlaced 60i or 50i. You have the best camera out there for under $4000.

Hell I don't have half the talent as most of you, but my footage is bringing home the bacon and that's alright by me. (that my footage is mediocre and paying the bills, he, he!)

Get jiggy with those scene file settings, live a little and experiment!

Start a progressive revolution!!!

You can use interlaced video but you want to be part of something great dont you?

Sorry sometime I just need a release!
 
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