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Old March 21st, 2008, 03:24 PM   #1
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Motion Smooth

Hi all,
I have had my HD100 for a couple of years, and got it for a specific series of projects in HD30P... very happy with the image, etc. I have avoided using it for other production shoots because I've never been happy enough with the image to feel confident selling it to clients. I know there are lots of forum members who have been doing just that, and I am confused about several problems I'm seeing that just don't seem to be troubling hardly anyone else, and I'm hoping someone can help.

1) Motion Smooth doesn't do anything. As soon as I import my HD30P footage into FCP, it's just as jerky as before. I see no difference whatsoever. Why is that? I have kept everything progressive through the chain, and no matter what, all motion is distractingly jerky. I understand about shooting for a progressive shutter as opposed to shooting for interlaced, but I just don't see any difference whatsoever with motion smooth.

2) SD60P is just as jerky as HD30P. How is that possible? They look identical to me in terms of motion artifacts. I see no evidence of the super-smooth motion discussed in this forum.

I've been shooting everything with 1/60 shutter, and haven't experimented with 1/30 yet, but I don't think I should have to based on what I've been hearing here.

3) DV60i, no matter what monitor I look at, including a professional Sony broadcast CRT 9", has way too much aliasing, especially on near-horizontal lines. It just looks really low-res and cheesy. I have tweaked the horizontal and vertical detail adjustments with very little effect.

These symptoms appear at all detail levels as well. I've tried everything from max to off. Of course with the detail off, there's much less aliasing, but the picture is terrible.

Any ideas? Thanks a lot!
Dave
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Old March 21st, 2008, 04:43 PM   #2
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Hi Dave,
I cant offer anything except query why your camera is not producing like it should. I shoot 3 broadcast commercials every week and mine is perfect. There must be something wrong.
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Old March 22nd, 2008, 07:16 AM   #3
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Dave, It will be much easier to diagnose if we could see some of the footage. Can you post a link to a 30 second clip of some of the raw footage in question? If so, post something with the shutter OFF, and no motion smoothing using Paolo Ciccone's T3 settings, that should make comparisons very easy with most of the members here who might be able to chime in on possible solutions.
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Old March 22nd, 2008, 11:05 AM   #4
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Thanks. I'll post a few files tomorrow.
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Old March 24th, 2008, 12:53 PM   #5
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Examples uploaded

I've uploaded three files to show what I'm talking about:

http://www.landhofilms.com/hd100/

Just right-click each to download the files.

HD30P, Shutter Off, motion smooth off, as a reference.

SD60P, shutter off.
This looks like standard 30p. I see no difference in the character of the motion between 30 and 60 frames.

HD30P, shutter off, motion smooth on.
I actually can see a difference with the motion smooth now - subtle and not very flattering but I see it. Is the effect of motion smooth supposed to be this slight?

Also a short DV clip. Notice how the car seems to absolutely shimmer from the aliasing on the near-horizontal lines during vertical moves. Is that normal for this camera? I've never seen this before on a professional camera.

The three m2t clips were made with DVHSCap, and I don't think there are any adjustments I could make really.

Thanks a lot for helping me out with this!
Dave
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Old March 24th, 2008, 09:53 PM   #6
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Hi Dave,

Are you comparing your captured material on a computer screen, or using a HD monitor? You probably won't see any difference between 60P and 30P on most LCD computer monitors, but I can assure you the difference is as clear as comparing 30P to 60i. 60P has a "video" feel to the temporal motion and is very very smooth. (Watch sports on the HD feeds of Fox, ESPN or ABC to get a feel for 720p60.)


As for the difference with Motion Smooth on or off it is harder to see unless you analyze comparison frames. I don't recommend that anyone actually use the motion smooth function because you will never have a single true progressive frame.

I'll explain how Motion Smooth works:

In 24, 25 and 30P mode the ProHD cameras sample the CCD at twice the frame rate. This means that the camera is actually sampling 60 (59.94) frames per second when in 30P (29.97P) mode, but throwing away half of those frames and only encoding every other one.
When Motion Smooth is turned on those "throw away" frames are utilized by creating a new "superimposed" frame out of every frame pair. This means that you will see a "double-image" or "ghost" on any movement on every single frame.
This is supposed to create the illusion of "smoother" motion, but it really seems more like a fake persistence-of-vision effect. I think if this is what you are after you are better off using a slower shutter speed to create a longer motion blur instead of a double image.

Of course the 200 series is capable of encoding all 60 frames sampled every second, making Motion Smooth unnecessary. You won't find "Motion Smooth" anywhere in the 200 series menu system. (replaced by DNR which may also cause a similar undesired effect.)

I've attached a couple comparison frame grabs from your samples. The one of the left is Motion Smooth OFF, the one on the right is Motion Smooth ON.
You can see very clearly the ghost image that precedes the natural motion blur when motion smooth is turned on. This is from the right-to-left pan but the ghost image precedes the motion blur on the left side which doesn't make sense.

Also, you may want to search this forum for "motion smooth." We've discussed this exact topic many times since 2005.
Attached Thumbnails
Motion Smooth-motion_smooth_off1.png   Motion Smooth-motion_smooth_on1.png  

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Old March 25th, 2008, 12:10 AM   #7
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Hi Tim,

Thanks for the comprehensive reply. What you're saying about motion smooth in HD30p makes perfect sense.

As far as the 60p mode goes, to be clear, you saw the 60p footage I uploaded specifically and it looked right to you? I'm looking at this on a pretty high quality CRT SD television, which I believe is adequate at least to judge motion artifacts (I wouldn't color correct with it!), and doesn't look smooth to me at all. The reason for the post is that I have read many posts here about motion artifacts, and what I'm seeing in both cases didn't seem to match what I've been reading.

Did you have a chance to check out the DV clip as well?

Thanks a lot.
Dave
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Old March 25th, 2008, 08:11 AM   #8
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Quote:
Originally Posted by Dave Coulter View Post
As far as the 60p mode goes, to be clear, you saw the 60p footage I uploaded specifically and it looked right to you? I'm looking at this on a pretty high quality CRT SD television, which I believe is adequate at least to judge motion artifacts (I wouldn't color correct with it!), and doesn't look smooth to me at all. The reason for the post is that I have read many posts here about motion artifacts, and what I'm seeing in both cases didn't seem to match what I've been reading.
If you are looking at your SD60P clip on a NTSC monitor then it is impossible for you to actually see 60P. The maximum frame rate/frequency for NTSC is 30P or 60i. Your NLE, or encoding software has likely thrown away every other frame to create 30P output. It is trickier to create a 60i NTSC output from the 480p60 file.
What software do you use for editing?

If you were to uprez your 480p60 material to 720p60 and watch it on a HDTV (say from a blu-ray or HD-DVD player) you would see that 60P temporal motion seems as "smooth" as 60i.
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Old March 25th, 2008, 09:50 AM   #9
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Nice to have you back Tim.
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Old March 26th, 2008, 12:55 AM   #10
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Again, I suppose that makes sense. I use FCP5... Is there a way to create 60i from the 60p file?

Does the DV sample look correct to you?

Thanks Tim,
Dave
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Old March 26th, 2008, 03:07 PM   #11
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Quote:
Originally Posted by Dave Coulter View Post
Does the DV sample look correct to you?
Yes. It looks exactly as NTSC DV should. If you are trying to watch this in QUicktime player you will need to go into "Movie Properties," click on Video Track, select the Visual Settings tab and checkmark "High Quality." DV quicktimes have a low-res single field preview mode that may be confusing your perception of the actual quality. Checkmarking "High Quality" overrides this for the Quicktime Player.

Quote:
Originally Posted by Dave Coulter View Post
...I use FCP5... Is there a way to create 60i from the 60p file?
Yes.

If you were to simply start editing 60P material into a 60i sequence FCP would throw away every other frame, hence creating 30P footage in your sequence. You can test this by applying the TC Reader filter to your 60P source and observing the results.

If you eventually want a 60i sequence from your edited 60P material I suggest you edit in 60P and create the 60i export file with Apple Compressor.

For example, let's say you shot 720p60 with an HD200 and you eventually want to cross-convert to 1080i60 for broadcast on the Discovery Channel. You also want to maintain the smooth motion of 60P by utilizing all frames in the conversion to 60i and not be limited to 30P in 1080.
First, edit your program in 720p60 sequences. Maintain 720p60 throughout the chain in FCP.
When you have locked your cut and you are ready to export 1080i, launch compressor and duplicate one of the Apple 1080i presets. I've used HD Uncompressed 8-bit for my example.
Now select your duplicate setting (it will be in custom settings and have the word "copy" at the end of its name) and enter Frame Controls in the Inspector. You'll notice that most of Apple's presets have Frame Controls set for automatic. This is great for most purposes except that the option for "Output Fields" is set to "Same as Source." Our source is progressive so compressor will automatically create progressive frames within our 1080i output file. We don't want this so click the "cog" to unlock the settings, set frame controls to "on," then set Output Fields to Top First for 1080i Uncompressed. This will force the output file to be interlaced and will utilize both even and odd numbered source progressive frames to be used in the interlaced output - giving you the original "smooth" look of 60P in 60i. Of course you will now have all the disadvantages of interlaced video.


If you are trying to do the same thing with 720p60 or 480p60 source to convert to DV NTSC (60i) then you will want to duplicate Apple's DV-NTSC Anamorphic compressor preset and set your Output Fields to "Bottom First." The DV codec uses bottom first field order, but most other professional interlaced formats use top first.

Good luck.
Attached Thumbnails
Motion Smooth-picture-1.png   Motion Smooth-picture-2.png  

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Old March 27th, 2008, 11:43 AM   #12
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That's great Tim. I'll try out that workflow as soon as I can. Thanks so much for all the time!
Dave
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