Progressive mode. A question about jaggies, artifacts, whatever you call it.

david jerome

david jerome

Well-known member
I hooked up my new DVX100b direct to my Sony TV and also a high quality Sony video monitor at work. Both monitors are interlaced. Went straight from camera to monitors with both video output and s-video output, same result. Using the F1 factory setting. I switched between progressive off & (30P, 24P, 24P ADV) everything else the same, still on F1. When in any of the progressive modes I see much worse jaggies on vertical lines with extremely slow panning. More noticeable when zoomed wide. I have heard that the jaggies, artifacts, aliasing, whatever you call it, is there because it’s an interlaced monitor. But I’ve never heard that progressive mode makes these jaggies worse. The traditional diagonal jaggies seem to be the same with progressive on or off. It’s the vertical lines that I’m seeing the difference. Also, changing the different detail settings in the scene menu doesn’t seem to affect the problem. Sorry for the long post but I wanted to make clear what I was talking about. Does anyone know what this is? And more importantly, is progressive mode worse on vertical lines than interlace mode when shooting for interlaced TV. Thanks for any insight on this.
 
I have watched this post and I am surprised that an answer has not been provided by some of the more knowledgable in this group. So I will venture a comment.

Interlacing artifacts do occur when you play 24p footage on an interlaced TV because of the blended frames created by the 2:3 pulldown. The DVX records 24p frames but then writes them to tape with the 2:3 pulldown inserted. NLE's like FCP and Premiere can detect whether the clip is 23.976 (24p) or 29.97 (60i/30p).

When you play footage from the NLE it will output the clips with 29.97 with pulldown to display properly (with some interlacing artifact) on interlaced TV.

If you output as progessive (make progressive DVD) The DVD will play the progressive properly on a progressive scan monitor. clean no jaggies or it (the player) will add 2:3 pulldown if connected to an interlaced device.

That said the question is whether there is pull down in the signal output from the camera or is it only applied to the signal when recorded to tape.

Personally I don't know, but would like to. I imagine it is but????

Why don't you record the same scene you are previewing when connected to one or both of the Sony's and then play it back from the camera. The tape should have pulldown and hopefully it looks better.

I am not an engineer but I shoot 24p and while it will display some artifacts (jaggies) they are not anywhere as noticeable as what you describe.

Last thought. You say you only changed the progressive setting but check to see if the vertical detail freq. is set to thick or thin, this is directly above the progressive setting. If set to thin this can be problemtic in some instances. I imagine in this case it might be as you are going straight to the TV and thin detail + Interlaced display are not friendly.

S Cannon
 
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Thanks for responding S Cannon. I tried recording to tape and playing back like you suggested and it looks exactly the same as the direct output from the camera. I also tried all the detail settings with no affect on the artifacting. 30P reacts the same as 24P and 24P ADV so i'm thinking it's simply the progressive nature and not the 2:3 pull-down introducing the vertical artifacting when panning. It really is a noticable test when switching between the modes and slowly panning.
 
It never looks very good when you're running straight out of the camera to an interlaced monitor. After you capture and output the footage, it will look great on a regular TV.
 
Chris Santucci said:
My guess is interlaced/progressive has nothing to do with what you're seeing.
Click to expand...

But when I switch between the two modes, interlace & progressive in the camera, the progressive mode is noticably worse on vertical lines when panning. So it must have something to do with progressive mode on an interlaced monitor. I would like to know if someone else can confirm this with their camera. I would like to know it's not just my camera and that it is the nature of progressive mode on an interlaced monitor, or maybe the nature of the DVX progressive mode on an interlaced monitor.

Thanks for the replies.
 
I put a chapter in The DVX Book about progressive footage on interlaced monitors. What you're seeing is normal, and you'll see it in any film footage that you watch for it too -- watch for sections where there's strong contrast in the image, like a white door in a dark doorframe; as they pan past it you'll see combing interlace artifacts. It's because you're showing progressive footage on an interlaced display.
 
Thanks Barry, I look forward to getting the DVX book. Should be here soon. I was hoping that was the case and not something wrong with my camera. I've just never actually heard or read this. I've actually heard people say that progressive has less artifacting on interlaced displays. I looked at some films on dvd tonight and saw the same interlace artifacts. Thanks for the simple and direct answer. Now I must be on my way to Best Buy to get an HD progressive display plasma TV. In my dreams.
 
I Owe An Apology

I Owe An Apology

I made this same comment on another post, asking "Why Does 24p Look So Crappy On TV."

Well, I'm here to tell you that I was wrong. Yes, everything stated thus far in this thread is true about watching progressive footage on an interlaced monitor. I was so bummed that I tried an "experiment" yesterday.

I shot some footage with my 100b at 24p (2:3), cinegamma, -3 master pedestal, 2nd ND filter, using alot of shallow depth of field and rack focus. I imported it to PPro 1.5 at 24p then exported it to MPEG-2 DVD at 24p. I played it on my DVD player and watched it through my 52 inch HD Sony Wega.

WOW!

I thought I was watching film. No jaggies. No interlace artifacting. So help me, it was a thing of beauty. Trust this camera, David. It delivers what it promises.
 
Thanks Hugh. I love this camera by the way. I just wanted to make sure mine was acting normal. It's not that the video looks bad. It's the vertical edges on panning. Like Barry said, you can even see it on DVD hollywood films. 30P does the same as 24p. I guess if Hollywood can live with it I can. Some day we won't have to I guess, when interlace monitors are a thing of the past.
 
David:

NTSC has been a challange forever in terms of picture quality in its own right. And now that progressive scan technology is changing the ability to provide cleaner looking and more filimic quality we are all impatient to use it to display our creative juices. But fear not the quality is there and it shines when you use a progressive scan display.

As Barry's book and DVD explain that film industry has been frusted for years by the strobing affect that appears from fast panning just as we in the world of video have been frustred by interlaced artifacts. Now that we have 24p we can be frustred by both issues. :furious3: But what a joy when we perfect our skills and find how well this camera works especially considering the price point. :)

Good shooting

S Cannon
 
Thanks S Cannon. I'm looking forward to getting a progressive scan display to see my dvx in all it's beauty. In the meantime I'll start creating something to watch on it.
Thanks for the replies and info.
 
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