24p on HV20 choppy?
 

I just purchased the HV20, mainly because I have heard so much about it's true 24p and film-like motion

I've been very impressed with the image quality so far on the hv20, but I've been playing around with the 24p and am not happy with the motion. It feels very choppy, with a 'rough' feel, almost like the video is being played in fast motion, but it doesn't feel natural.

This was playing it back through component on my HDTV. Is there a reason why the 24p is so choppy. I watched a few DVD's, and the films i saw (which are 24p aren't they?) were smooth, certainly not 60i smooth, but the film had a nice motion to it, it wasn't annoying to the eye, like the 24p i was seeing on my TV, from this HV20 camera.

Can someone sled some light on this, i've heard so many people rave about the 24p on this camera, surely i must be seeing something different, it just feels much to rough to be enjoyable.

Jay,
In many of the posts in this and other forums about 24P it has been mentioned that 24P does not handle motion very well. Leads to kind of jittery video.
I also have the same question as you that why the movies don't look that Jittery when there is motion involved.
So I took some 24P video of cars moving at about 50mph. I did shoot in Tv mode fixing the shutter speed. And what it seems from the LCD is that at 1/48 the motion looked lot smoother. Though I am yet to check them in computer. I plan to do it sometime tomorrow or day after. I would let you know how it went.
I am also going to remove pulldown to see if that effects the visual quality. Which I think might also play a role.

Tips
 

http://yousillyman.blogspot.com/2007...rames-per.html
http://yousillyman.blogspot.com/2007...lling-man.html

24p is best for static shots and slow movement. TV 48 plus a custom effect allows you to have settings similar to cinemode but with a more hard set shutter (cine will go out of 48 in very low light). There are quite a few 24p samples in DVinfo. Look for the shots done by Solomon Chase, they are very good. In some cases you may want to shoot mixed tapes and then turn them both to 24p in final form.

The visually nice part of the 24p is the 'p'. Interlace "halves" your resolution because you only see every other row per field displayed. There are creative ways around this too (60i-60p (interpolated)-24p).

Now why is film 24p smoother than the ones we shoot? I'm still figuring that out myself. But from the years of home videos in 30p/24p I've found the key to be stabilization and limited panning. If you're moving its best to avoid pitch and yaw movement. How do you accomplish that? Be creative. In one of the links above, I used a moving walkway. In some cases I've used a DIY figrig which uses your arms to dampen some of the motion (you have to pay attention). In the past I would use a heavy tripod as a "fake" steadicam.

Are you shooting in auto? Your shutter probably dropped to 1/24th. As the other guys said, shoot at 1/48th shutter speed and 24p is fine.

Also, you might be having issues with the rolling shutter inherent in the CMOS chip of the camera. If you bounce around a lot or if your subject does it can cause issues. This is not however a 24p issue, it's a CMOS issue.

Of course it helps to know how to shoot 24p too. Seems a lot of folks in the "video world" that have never shot film do not know how to shoot good 24 frames per second footage.

There are tons of resources out there to learn the "rules". But the most important one is probably simply follow your "subject" as they move across the frame. And if there is no "subject" pan very slowly... :)

thanks for the tips guys.

have you ever seen those TV shows, where they will go into a fast motion car chase, and then they use that effect, where the camera is more shaky and it has that fast motion feel. I remember seeing it on Alias, alot of the TV shows today use it for like flashback effect, its just a more 'rough' motion. That was what I was getting, instead of the regular, smoother 24p that you see on most TV shows during regular scenes.

Any other settings I can adjust to get the smoothest 24p possible?

If it's what I think you're talking about... you can get that effect by changing the shutter speed to 1/100th or higher. Kind of a "Saving Private Ryan" look. Although it won't be "smoother", just more kinetic feeling.

Well ya that look that you see during all the battle scenes in Saving Private Ryan, that's the type of motion I was getting whenever I adjusted this camera to 24p. It's a cool look, but I'm looking for something more easy on the eye, that regular 24p motion you see with most scenes shot on film.

i was watching the 'rain' video by solomon chase, it did look very good. Why was his 24p so smooth and jitter-free?

Whenever I shoot 24p and watch it back, everything is juddering all over the place, and the image is never smooth unless the picture is completely still. I'm becoming very disapointed with the 24p on this camera, it doesn't seem to be even close to as smooth as 24p film, and it just annoying to look at, 60i wouldn't look professional, but at least it won't be hard on the eyes.

In Solomon's "rain" movie he shot with 1/100 shutter speed at 24p just as I described earlier. But he also slowed it down. Maybe that's what you're seeing and calling it smooth? But that is an effect.

Not really sure what you're doing, but the HV20's 24p looks great. I have shot with virtually every 24p camera there is including big rigs like the Varicam and Sony HDCAM and the HV20's 24p motion, etc. looks the same. It's NOT the same image quality, but the same 24p look and feel.

One thing too, 60i is professional, but it just doesn't look like film. Depends on what you're using the camera for...

Ok i just went out and shot some more 24p footage. Pressed reset to clear camera to defaults, adjusted to hd24p mode, set shutter to 1/48.

Recording a bunch of stuff on a tripod, keeping the camera still, not moving very fast, trying different things. I hook up the component cable to my HDTV, watch the footage, its just not there. It doesn't look like the motion of film, it looks like it's film with some kind of a fast motion effect, or almost as if it was like 15fps or something, exactly what you'd see during a car chase on a TV show, CSI Miami, uses this kind of motion too. I'm sure it would look good on certain things, but not for any regular film your trying to make.

Is this what everyone is happy with, with the 24p. Or are are you all seeing a 24p motion that does have the smooth look that you see in any regular scene shot on 35mm film.

Jay,
I have been made pretty busy this weekend! So have not been able to see my footage yet in the computer/TV.
But what you did shoot seems to be same as mine. Did they look quite smooth in the LCD?
Did you try to download the footage in computer, remove pulldown to make it a proper 24P footage and then view it?

i just watched it straight onto my tv, playing it off the tape

Hmm. may I suggest you to download to computer, make true 24P and then make it smaller (so that the computer does not choke playing it) and then play.
Just to see if that creates any difference.
Thats what I would try to do tonight if I am left with some energy after going back home! :-/

Edit: By the way if you play the tape just in the cam how does it look in that tiny LCD? I am asking it because if they look smooth then I would expect the same result as you in the TV.

it looked about the same on the tv as it originally did on the viewfinder.

here's something i found out just now doing a test. When I adjust the shutter to 1/24....I'm actually happy with the motion, it feels smooth and more like the motion i'm used to from film. The problem, of course is the motion blurring, which is much more obvious at 1/24 than at 1/48 or 1/60

As soon as I switch to 1/48 or anything higher, the motion blur gets better, but that motion becomes different, and it feels as if that fast motion effect is being used again. As of right now, I think I like the 1/24 shutter motion the best, but the motion blur is very obvious on fast movements of the camera.

Jay, for what it's worth, when I record in 24p mode and play it back on my 48" HDTV via the component cables, the footage looks pretty smooth. I'm not sure what shutter speed I'm using, as so far I've mostly shot using the "cinema" mode.

The fact that you say it looks choppy right out of your camera has me worried that your camera might have a defect. You can see a lot of people have posted 24p footage that looks pretty good (at least in my opinion). I don't mean to make you panic; I was just surprised to read about your problem.

ok i was finally able to upload some sample video (i have dial up) so that you can see the issue i'm having.

could a few people who know this camera have a look at this footage, and see if it looks normal to you, hv20 shooting in 24p mode, 1/48 shutter

http://ia340903.us.archive.org/1/ite...ple/shakey.wmv



That is what I get whenever playing back on my TV from raw tape as well, so it's not a computer performance/rendering issue. It just looks 'fast motion' to me, as if there is motion effect on it for a special look. Am i just shooting wrong, is my camera actually not working correctly, or is it fine and it's just my eyes?

I've been playing around with the 24p and am not happy with the motion. It feels very choppy, with a 'rough' feel, almost like the video is being played in fast motion, but it doesn't feel natural.

Is there a Can someone sled some light on this, i've heard so many people rave about the 24p on this camera, surely i must be seeing something different, it just feels much to rough to be enjoyable.[/QUOTE]

JAY / study the following LINK / Do not shudder at the judder /

This link will bring you closer to the answer.

http://hd24.com/dont_shudder_at_the_judder.htm

Herman,

Jay, there is definitely something wrong with your footage. Take a look at the Rio footage, or the Sunny Day footage that has recently been posted here. For handheld, moving around a lot, it looks pretty smooth. I just posted some footage that has both handheld and tripod use, and I think it's pretty smooth. You can check it out here (it's called Afternoon Rain):

http://www.jsendicott.com/dvinfo

It looks to me like your watching 24p inside of a 60i timeline. But, the bad news is that it should not look like that when watching directly out of your camera on a TV.

Jay, I noticed blended frames in your footage (they overlap clearly) I couldn't get out with any player I have. So I assume they were rendered like that when you converted your footage to the wmv file. As I hardly believe the footage looks the same straight off the cam, I suggest you post a small uncompressed mpeg or m2t sample for us here to judge where the bug is.

I'm really thankfull that I live in a PAL land...so much less trouble (none, that is) with 25P...and I love it, love it, love it! ;)

Joel I watched your clip, with the rain shots with the letus adapter. It looked very good, there wasn't a lot of panning/camera movement, but i'm curious to know whether if it was my hv20 behind your lens adapter, whether the image would be choppier.

Could anyone else look at that footage? Any settings on the camera I might have adjusted by accident that would give it that look? I just don't see how I every get Future Shop (store i purchased from) to go for swapping for a different HV20, they would never understand the importance of the motion i'm after, and would think it was just fine.

honestly, i'm not even that worried about the judder, I can live with a bit more judder, i remember back when I only had a 60i SD camera, and all I wanted was to get the judder like film had. Now i have a bit too much but oh wel....


it's the motion. If you watch that clip, it feels like a music video, or a car chase on a TV show, it doesn't feel like regular 24p. Does anyone else see when I'm mean, after watching that clip. I just can't tell what it is and whats causing it.

Jay,

The reason film may look smoother than what you are getting is probably from a few resons.

1. Not shooting smooth/steady enough

2. The edge enhancement used to get a sharper image in camera will result it a jittery image campared to film.

3. I'm not sure, but you may want to remove the pulldown and then have a look. If you put that into a 24fps timeline straight up, it WILL look choppy.

I think Jeremy's right. Especially concerning the pulldown. Like I said, your wmv file shows serious frame blending. You can litteraly see 2 frames overlapping each other (have a look at the still I grabbed). That's NOT what 24p is supposed to look like with this cam, BUT it will look like this unless pulldown is removed (NTSC owners, please correct me if I'm wrong). I guess if you want to achieve that look you're after you have to remove pulldown first.

I suggest the following: capture some 24p into your computer and, without further editing it, watch it with a player like PowerDVD or VLC. These players are capable of deinterlacing (you have to turn it on first), that is removing the pulldown 'on the fly' (worked for me with every single clip I downloaded here). If it still doesn't look right to you, it must be something else (maybe not shooting steady enough, like Jeremy said).

- OK i took a "direct' screenshot from the original m2t capture, no rendering here at all involved.

heres is the raw screenshot, showing this blending i'm getting straight from my HV20 raw footage. is this why i'm getting that 'fast motion' music video style look to my footage.

Jay,

Just watched your footage... it was NOT shot at 1/48 shutter. Looks more like 1/100 or greater. You definitely have the "Saving Private Ryan" effect going.

You said you shot at 1/48, but did you lock it using TV mode? If you did then your camera may be malfunctioning.

This has nothing to do with 3:2 pulldown.

Sorry - I see that the pulldown issue has been addressed.

Does every frame look like that? With 24p only 2 out of every 5 frames should appear interlaced, no matter what the shutter speed.

Once again, It will NOT play back at 23.98 if you do not remove the pulldown. HDV will capture the footage at 60i and it will continue to be 'interlaced' like that until you remove it.

Did you capture it with HDV? If so, it was not 'raw' like you mentioned.

Try removing the pulldown and have a look at it again. There are plenty of threads on how to do that properly.

Jay, from looking at your video I would say you have two things going:

1. You seem to have a high shutter speed going on here (someone might have already mentioned this). This would cause that "judder" llike look.

2. You are also viewing that ghosting effect of "pulldown."

I think together they caused your video to look this way. Higher shutter speeds (1/120 or above) can cause a judder during movement. Yeah, it's like the Saving Private Ryan look. High shutter speed coupled with 60i can give great slow otion (I'm sure you know that) but I think you might have had your shutter faster than 1/48 or 1/60. Put that together with the pulldown effect and I would expect video to look exactly like this. As mentioned before, maybe you can try removing the pulldown. You definately will see the difference.

I'm trying to stay away from the whole pulldown thing, because I'm not very good at coding, and I had don't have any extra software like premiere and cineform. I just have vegas 7.

I used hvsplit to capture the footage as a 60i 29.97fps m2t, then i just skipped through each frame individually, and found that ghosting look (see attached picture from before)

so a high shutter speed would be the explanation of that motion look. I'll try again making sure I'm shooting at 1/48.

don't give up on pulldown removal
 

Jay, pulldown removal really helps with the annoying ghosting/blending.

Steve's thread on Vegas and 24p pulldown removal with free tools
http://www.dvinfo.net/conf/showthrea...t=94235&page=5

Here's a (not so) short brief on the process that Steve automates:
http://yousillyman.blogspot.com/2007...-hv20-m2t.html

Give it a try, you will like the output.

Jay,
I would just like to second Mike. If you download Steve's exe and all the other files as mentioned. pulldown issue wont look any complicated. And it would definitely not need any coding from your part. Even understanding it is not required!
And I would also mention that my footage at 1/48 does not look this jittery.

So Mike, it looks rather complex. If you use Cineform with Vegas or PPro what do you have to do for pulldown removal to get the best quality? How about with a project that will have mixed 24p and 60i shots? Thanks - PK

It only appears to be
 

Paul, it appears complicated to do the first time setup because we're integrating multiple packages with at least 1 of them not allowing bundling. Once you have the parts together, you run Steve's exe and you tell it where all the m2t files are. Then you let it run. Look for the output when you're done and drop it into your timeline.

I've mixed 60i and 24p footage with no problem. If your NLE could already do it then its okay. Of course when your final output is progressive, it's best to deinterlace the 60i in your timeline ... that's an NLE function.

thanks for your help guys, i appreciate it. I was finding then by doing the pulldown, I ended up with these huge AVI files.

I tried importing these into Vegas to edit, but i guess my computer was too slow, and got a choppy and wouldn't play. Can i convert these back to mpeg format, and then edit, and then render to mpeg again? Or is there going to be quality loss rendering from AVI to m2t, then editing then rendering to m2t again?

How do you guys usually do this, surely you don't edit directly using those AVI files, they are huge, i don't even have enough hardrive space for them

Actually Jay, that's what I did. I just started using Steve's method..but...instead of rendering several files to put in the timeline I saved my edited footage from the Vegas timeline into the MPEG 2MainConcept format (HDV) and THEN I ran that through Steve's .exe file. To my eyes it worked perfectly and when I blew up the footage...its quality seems identical to the original. (I have not even used the "Uncompressed" yet)...but it should look even better. But honestly the footage does not show any macroblocking or any other type of perceptable degradation.

I'm sure there are folks here who will not agree with my methodology but I am amazingly satisfied. Give it a try.

It will also enhance the rolling shutter effect pretty badly.

Jay,
I am in fact using those huge avi files! I use Lagarith compression while saving them (not uncompressed).
And as I told you before. Just to see that pulldown removal is improving smoothness in your videos, you can open the avi files back in VirtualDub/DubMod and resize to a much smaller size before playing.
Smaller size would make it easy for your computer to play them.

Ajit B.

[QUOTE=Mike

Now why is film 24p smoother than the ones we shoot? I'm still figuring that out myself. [/QUOTE]

Motion judder is also visible in the film world. The one thing that smooths it out is that rapid movement will also cause a slight blur on the exposed frame, which masks the artifact. I suspect our video sensors have no equivalent of a motion blur visible in film.

I saw shaky.wmv and to me it doesn't look like 1/48 shutter setting. I could be wrong but at a glance that's how it looks to me. Anyway I'll share what I felt about 24fps of hv20 so far.

I noticed the stroby feel of 24p /48shutter motion of HV20, but it seems particularly so on this small LCD. When I hook it up to a 24inch monitor via component output and watch the same movement it feels more like filmic smooth 24p footage. It doesn't look as stroby as camera's LCD flipout panel for some reason. (setting 24fps 1/48 shutter)

The other possible contributing aspect may be the depth of field and the weight of the camera. 35mm cameras as we all know have much shallower DOF. More often than not we see the clean target object against slightly blurred background, so even in motion it is less jitterly because half of the picture was already blurry. HV20 captures pretty much everything very sharp (assuming the focus has set right) so the motion judder pops stronger to your eyes.
And of course the weight. Unless you are using a tripod or a steadycam rig, HV20 in your hand records even a slight tremble of your hand and it can move around much freely compared to a typical film cameras in the same handheld situation. Optical stablization helps but in big HD res its effect doesn't seem as great as SD cams. So by default 24p footage out of a light HD cam should look more stroby, but it's a shortcoming that can be fixed.

Paul, great to see you here! Did you get hv20? Isn't it a fun camera? :)