Motion artifacts, help! at DVinfo.net

Patrick Janka · March 19th, 2011, 10:47 AM

Here's the first real video I've shot with the GH2, and my first real estate video, and my first video using the Merlin (trifecta!): YouTube - 14139 Chicora Crossing Blvd., Orlando - Avalon Park, FL

I'm not all that happy with it. I filmed it using the stock Lumix 14-42mm lens, only on the wide end. The car scene was all hand-held out the window. I used iA mode for a lot of it so when I walked into rooms with varying lighting the camera adjusted itself. My big issue is that when I'm panning the camera, or in general moving with it everything gets really artifacty and gross. Look especially at the door on the left at 2:12 as I walk out of the room through that entrance (and the footage of the hall as I exit looks atrocious, too). It's very jerky looking. Also, shots of the walls seem to reveal weird digital circular patterns. Can someone explain what's going on here? Anyone else experience this sort of thing when panning/tilting/trucking? Thanks.

Jeff Harper · March 19th, 2011, 12:03 PM

First, the issue is NOT the camera, so you can rest easy on that. If I'm mistaken and the raw footage looks like that, then I"m wrong.

The vast majority of your issues appera to have to do with how it was converted.

You might have a bit going on going up the stairs that has more to do with your lens, as there was simply not sufficient light for it.

You need to address how you handle your editing, conversion primarily, IMO.

Martyn Hull · March 19th, 2011, 12:21 PM

surely if he is not happy with the footage the first thing to do is check direct to tv play via hdmi and even direct raw file play on the pc ,if its still bad its not pc related.

Patrick Janka · March 19th, 2011, 05:02 PM

Jeff, I went back and looked at the raw footage. The clips taken in Ai mode were actually 1080i, not 1080p, and the frame rate was actually 30fps. I was editing in Premiere in a 1080p24 timeline. I went back and tried to "interpret" the footage to conform by de-interlacing the footage and adjusting the frame rate, but it still didn't look great. I also think part of the problem was that when shooting in Ai it adjusted the ISO to the max setting, giving me some shots that were horribly artifacty (is that a word? lol). In any event you'll notice on things like the white fence I was having bad moire problems, which happened regardless of camera setting.

Jeff Harper · March 19th, 2011, 05:29 PM

I'm a big proponent of using automatic modes. But not with a DSLR for professional work like you're doing.

You are still probably not handling your footage properly, it sounds/looks like to me. In Vegas, there is a method of bringing in footage and then clicking on it so the project matches the footage exactly as it is. That is where you should start, IMO. 1080i with the GH2 is 60i, even though it appears to be 30fps when you right click on it in windows.

I suggest you start at the beginning, and go to the Premier forum, and tell them the mode you shot in (1080 60i), tell them what you need to do, and get some answers there. You will likely get a variety of answers, some correct, some not, but at least it's a start.

I also suggest you might shoot in 720p, to avoid interlacing issue also, which is what I've done. You can still work with 1080i, but it is one thing less to worry about if your footage is already progressive.

720 is also better when resized than 1080, at least according to what I've read. 1080 is larger, and gives your more room to work, as some will tell you, so I don't know. I've been finding 720p footage to very nice to work with.

Jeff Harper · March 20th, 2011, 01:33 AM

Patrick, watch the video below as an example. It was low light, no artifacts or issues as you had. Why would that be, you might ask.

The first time I rendered it out I had similar issues to yours, because I handled it wrong. Then I did it correctly, and bam, all issue gone.

I started a thread just like you did right after I shot my first video a couple weeks ago. I had the same problem. Someone suggested it was moire, but they were mistaken. It was deinterlacing artifacts, a few knowedgeable members guided me through the process of fixing it.

Handling HD footage in post is a huge issue.

This issue comes up over and over again, I was not the first, and as you prove, I was not the last to have the problem.

Patrick Janka · March 20th, 2011, 05:25 PM

Jeff, recording in 24p (cinema mode) not only gives you a resolution of 1080p, but it records at a higher bit rate than any of the other settings. 720p gives you a lower bit rate and fewer lines of resolution, so I don't see the benefit, unless recording 60p for slow-mo in post. I seem to run into moire in cinema mode, and it's not from ingesting footage, because I can see it on the camera's lcd/viewfinder as I'm recording. I'll need to play with some settings in Premiere to make sure I'm doing everything right. Perhaps someone who uses Premiere can give me a breakdown of their work flow? The only time interlacing comes into play is if recording in 1080i, which I never do, but happened to accidentally by using the iA mode.

I generally don't film automatic anything for specifically reasons like this, things happen that are out of my control. I like to know everything that's going on. Also, I can't expect the camera to know what it is I'm trying to do. Occasionally I'll use autofocus if I'm locked down or auto white balance in a pinch.

btw, Jeff, I didn't see a link to the footage you told me to check out in your last post.

Jeff Harper · March 20th, 2011, 08:14 PM

Patrick, you can shoot at any mode you wish. 24p is not an option for me. I shoot weddings for a living and most of my stuff ends up on DVD. 720 resizes better than 1080, at least that's what I've been told.

24p is not a viable option for me as a wedding videographer. What do I do with the footage after I shoot it? Rencode it to 60fps so I can put it on a DVD? It's a excercise in futility for me, and a time waster, IMO.

I am shooting with the end result in mind, which is the best place to start, IMO.

Shooting in 24p requires a style of shooting that does not lend itself to what I do for a living. It creates potential issues that makes what you are going through with your real estate video seem like a walk in the park.

If you already know or are willing to learn how to shoot within the confines necessary for 24p, and if your final destination for your product calls for it, great.

Jeff Harper · March 20th, 2011, 08:17 PM

Here you go Patrick. The camer work sucks, and I know it. But more importantly I ran at 100 ISO in a fairly dark church, and there was no moire, no nothing.

Patrick Janka · March 20th, 2011, 09:05 PM

Jeff, what's wrong with shooting a wedding at 24p? Just because you render out to 60i for DVD doesn't mean you have to shoot at 60i, as well. I shot a wedding on a Canon XHA1, and I believe I shot it in 30p. I don't believe I've heard that 720p resizes better than 1080p. Do you have any links to that?

Jeff Harper · March 20th, 2011, 09:31 PM

Patrick, shooting in 24p and achieving good results is not as simple as turning the camera on and shooting in 24p.

From Wikepedia: "In general, 24 frames-per-second video has more trouble with fast motion than other, higher frame rates, sometimes showing a "strobe" or "choppy" motion, just like 24 frame/s film will if shot as if it's video, without careful panning, zooming, and slower camera motion. It is therefore not well-suited for programming requiring spontaneous action or "reality" camerawork."

24p is lovely. But it is not generally suited for my kind of work or shooting style.

I have to deal with the realities of shooting weekly 3 camera weddings and as a result 24p is neither practical nor sensible.

Patrick Janka · March 20th, 2011, 11:39 PM

Fair enough. It seems to me that the 24p on the GH2 exhibits much less motion blur than on my Canon XHA1, so I've gotten accustomed to just shooting everything in 24p on the GH2. If you're filming in 720p your frame rate is automatically 60p, I believe. I think the only interlaced option is to shoot in 1080i. Is this right? Either way, I might shoot real estate vids from now on in 720p60 due to all the camera movement.

Jeff Harper · March 21st, 2011, 01:11 AM

I would. And you're already progressive, so it should transcode nicely.

Martyn Hull · March 21st, 2011, 01:16 AM

24P may have more resolution but it is not blatently obvious i have done various tests and i know watching on youtube via a pc monitor is not the best way to judge but i have watched and studied on my large screen hd tvs as well and 720P is far from bad.
YouTube - BEER RESOLUTION TEST.mp4

Martyn Hull · March 21st, 2011, 06:43 AM

One thing the stutter on 24P is caused by my software not the GH2s fault there.

March 19th, 2011, 10:47 AM	#1
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Motion artifacts, help! Here's the first real video I've shot with the GH2, and my first real estate video, and my first video using the Merlin (trifecta!): YouTube - 14139 Chicora Crossing Blvd., Orlando - Avalon Park, FL I'm not all that happy with it. I filmed it using the stock Lumix 14-42mm lens, only on the wide end. The car scene was all hand-held out the window. I used iA mode for a lot of it so when I walked into rooms with varying lighting the camera adjusted itself. My big issue is that when I'm panning the camera, or in general moving with it everything gets really artifacty and gross. Look especially at the door on the left at 2:12 as I walk out of the room through that entrance (and the footage of the hall as I exit looks atrocious, too). It's very jerky looking. Also, shots of the walls seem to reveal weird digital circular patterns. Can someone explain what's going on here? Anyone else experience this sort of thing when panning/tilting/trucking? Thanks.

March 19th, 2011, 12:03 PM	#2
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Motion artifacts, help! First, the issue is NOT the camera, so you can rest easy on that. If I'm mistaken and the raw footage looks like that, then I"m wrong. The vast majority of your issues appera to have to do with how it was converted. You might have a bit going on going up the stairs that has more to do with your lens, as there was simply not sufficient light for it. You need to address how you handle your editing, conversion primarily, IMO. __________________ "The horror of what I saw on the timeline cannot be described."

March 19th, 2011, 12:21 PM	#3
Martyn Hull Major Player Join Date: Aug 2008 Location: England Posts: 444	Re: Motion artifacts, help! surely if he is not happy with the footage the first thing to do is check direct to tv play via hdmi and even direct raw file play on the pc ,if its still bad its not pc related.

March 19th, 2011, 05:02 PM	#4
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Re: Motion artifacts, help! Jeff, I went back and looked at the raw footage. The clips taken in Ai mode were actually 1080i, not 1080p, and the frame rate was actually 30fps. I was editing in Premiere in a 1080p24 timeline. I went back and tried to "interpret" the footage to conform by de-interlacing the footage and adjusting the frame rate, but it still didn't look great. I also think part of the problem was that when shooting in Ai it adjusted the ISO to the max setting, giving me some shots that were horribly artifacty (is that a word? lol). In any event you'll notice on things like the white fence I was having bad moire problems, which happened regardless of camera setting.

March 19th, 2011, 05:29 PM	#5
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Motion artifacts, help! I'm a big proponent of using automatic modes. But not with a DSLR for professional work like you're doing. You are still probably not handling your footage properly, it sounds/looks like to me. In Vegas, there is a method of bringing in footage and then clicking on it so the project matches the footage exactly as it is. That is where you should start, IMO. 1080i with the GH2 is 60i, even though it appears to be 30fps when you right click on it in windows. I suggest you start at the beginning, and go to the Premier forum, and tell them the mode you shot in (1080 60i), tell them what you need to do, and get some answers there. You will likely get a variety of answers, some correct, some not, but at least it's a start. I also suggest you might shoot in 720p, to avoid interlacing issue also, which is what I've done. You can still work with 1080i, but it is one thing less to worry about if your footage is already progressive. 720 is also better when resized than 1080, at least according to what I've read. 1080 is larger, and gives your more room to work, as some will tell you, so I don't know. I've been finding 720p footage to very nice to work with. __________________ "The horror of what I saw on the timeline cannot be described." Last edited by Jeff Harper; March 20th, 2011 at 01:24 AM.

March 20th, 2011, 01:33 AM	#6
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Motion artifacts, help! Patrick, watch the video below as an example. It was low light, no artifacts or issues as you had. Why would that be, you might ask. The first time I rendered it out I had similar issues to yours, because I handled it wrong. Then I did it correctly, and bam, all issue gone. I started a thread just like you did right after I shot my first video a couple weeks ago. I had the same problem. Someone suggested it was moire, but they were mistaken. It was deinterlacing artifacts, a few knowedgeable members guided me through the process of fixing it. Handling HD footage in post is a huge issue. This issue comes up over and over again, I was not the first, and as you prove, I was not the last to have the problem. __________________ "The horror of what I saw on the timeline cannot be described."

March 20th, 2011, 05:25 PM	#7
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Re: Motion artifacts, help! Jeff, recording in 24p (cinema mode) not only gives you a resolution of 1080p, but it records at a higher bit rate than any of the other settings. 720p gives you a lower bit rate and fewer lines of resolution, so I don't see the benefit, unless recording 60p for slow-mo in post. I seem to run into moire in cinema mode, and it's not from ingesting footage, because I can see it on the camera's lcd/viewfinder as I'm recording. I'll need to play with some settings in Premiere to make sure I'm doing everything right. Perhaps someone who uses Premiere can give me a breakdown of their work flow? The only time interlacing comes into play is if recording in 1080i, which I never do, but happened to accidentally by using the iA mode. I generally don't film automatic anything for specifically reasons like this, things happen that are out of my control. I like to know everything that's going on. Also, I can't expect the camera to know what it is I'm trying to do. Occasionally I'll use autofocus if I'm locked down or auto white balance in a pinch. btw, Jeff, I didn't see a link to the footage you told me to check out in your last post.

March 20th, 2011, 08:14 PM	#8
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Motion artifacts, help! Patrick, you can shoot at any mode you wish. 24p is not an option for me. I shoot weddings for a living and most of my stuff ends up on DVD. 720 resizes better than 1080, at least that's what I've been told. 24p is not a viable option for me as a wedding videographer. What do I do with the footage after I shoot it? Rencode it to 60fps so I can put it on a DVD? It's a excercise in futility for me, and a time waster, IMO. I am shooting with the end result in mind, which is the best place to start, IMO. Shooting in 24p requires a style of shooting that does not lend itself to what I do for a living. It creates potential issues that makes what you are going through with your real estate video seem like a walk in the park. If you already know or are willing to learn how to shoot within the confines necessary for 24p, and if your final destination for your product calls for it, great. __________________ "The horror of what I saw on the timeline cannot be described."

March 20th, 2011, 08:17 PM	#9
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Motion artifacts, help! Here you go Patrick. The camer work sucks, and I know it. But more importantly I ran at 100 ISO in a fairly dark church, and there was no moire, no nothing. Low light videography using the Panasonic GH1 with Canon lenses on Vimeo __________________ "The horror of what I saw on the timeline cannot be described."

March 20th, 2011, 09:05 PM	#10
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Re: Motion artifacts, help! Jeff, what's wrong with shooting a wedding at 24p? Just because you render out to 60i for DVD doesn't mean you have to shoot at 60i, as well. I shot a wedding on a Canon XHA1, and I believe I shot it in 30p. I don't believe I've heard that 720p resizes better than 1080p. Do you have any links to that?

March 20th, 2011, 09:31 PM	#11
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Motion artifacts, help! Patrick, shooting in 24p and achieving good results is not as simple as turning the camera on and shooting in 24p. From Wikepedia: "In general, 24 frames-per-second video has more trouble with fast motion than other, higher frame rates, sometimes showing a "strobe" or "choppy" motion, just like 24 frame/s film will if shot as if it's video, without careful panning, zooming, and slower camera motion. It is therefore not well-suited for programming requiring spontaneous action or "reality" camerawork." 24p is lovely. But it is not generally suited for my kind of work or shooting style. I have to deal with the realities of shooting weekly 3 camera weddings and as a result 24p is neither practical nor sensible. __________________ "The horror of what I saw on the timeline cannot be described."

March 20th, 2011, 11:39 PM	#12
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Re: Motion artifacts, help! Fair enough. It seems to me that the 24p on the GH2 exhibits much less motion blur than on my Canon XHA1, so I've gotten accustomed to just shooting everything in 24p on the GH2. If you're filming in 720p your frame rate is automatically 60p, I believe. I think the only interlaced option is to shoot in 1080i. Is this right? Either way, I might shoot real estate vids from now on in 720p60 due to all the camera movement.

March 21st, 2011, 01:11 AM	#13
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Motion artifacts, help! I would. And you're already progressive, so it should transcode nicely. __________________ "The horror of what I saw on the timeline cannot be described." Last edited by Jeff Harper; March 21st, 2011 at 07:11 AM.

March 21st, 2011, 01:16 AM	#14
Martyn Hull Major Player Join Date: Aug 2008 Location: England Posts: 444	Re: Motion artifacts, help! 24P may have more resolution but it is not blatently obvious i have done various tests and i know watching on youtube via a pc monitor is not the best way to judge but i have watched and studied on my large screen hd tvs as well and 720P is far from bad. YouTube - BEER RESOLUTION TEST.mp4

March 21st, 2011, 06:43 AM	#15
Martyn Hull Major Player Join Date: Aug 2008 Location: England Posts: 444	Re: Motion artifacts, help! One thing the stutter on 24P is caused by my software not the GH2s fault there.