How to get best quality EX1 Slow Motion?

Steve Phillipps · December 22nd, 2008, 01:30 PM

Yes, that's the easiest way to do it - you mean with the SQ Motion function in the menus yes? In this way you can also view it at slomo speed straight off in-camera, something you couldn't even do with the old Varicams!
Steve

Matt Davis · December 22nd, 2008, 01:30 PM

Quote:

Originally Posted by Perrone Ford

It was hard to judge well because of the difference in framing, but the EX1 certainly looked smoother in slow mo.

Okay, here's another 'all about slomo' movie, not EX1, but useful for Compressor users:

http://www.vimeo.com/779651

No skimpy women with underwear, but would agree with previous posts that EX1 clip looked smoother, and that generating frames - no matter how beautifully - doesn't compete with capturing more frames per second from the get go.

Steve Connor · December 22nd, 2008, 01:45 PM

Quote:

Originally Posted by Perrone Ford

It was hard to judge well because of the difference in framing, but the EX1 certainly looked smoother in slow mo.

As an aside, how was this lit? Looked quite good actually.

Lit by very experienced DOP (not me!) just 3 lights. There's some much more spectacular footage from that shoot but I'm not allowed to post it!

Craig Seeman · December 22nd, 2008, 01:55 PM

Overcrank in camera runs at much higher data rate so when played back at your target speed, you get real (not synthesized) frames at 35mbps VBR. In fact that high data rate is why SDHC and Sony hard drive can't do overcrank to max frame rate (apparently due Sony's built in USB limit though). I think real frames are better than synthesized frames otherwise Phantom cameras would rent for so much.

Steve Phillipps · December 22nd, 2008, 01:58 PM

Is that actually correct Craig, surely at 720/60P you've got the same amount of data as 1080/30P (ie twice the rate but half the pixels)?
Steve

Craig Seeman · December 22nd, 2008, 02:19 PM

Yes actually correct and verified.
720p24/60 uses about 2.5x the data rate that 720p60 uses.
The XDCAM spec is 35mbps VBR playback. In order to achieve that playback rate a lot more data must be recorded per second. It's also one reason why DPs prefer shooting with high speed video over synthesized frames.

720p60 (NOT overcranked) is exactly the same data rate as 1080p30.

BTW on a tangent 720p24 (23.98) does have more data per pixel that 1080p30. The data rate is per second so at smaller frame size and fewer frames per second, you get more bits to describe a give "pixel."

Quote:

Originally Posted by Steve Phillipps

Is that actually correct Craig, surely at 720/60P you've got the same amount of data as 1080/30P (ie twice the rate but half the pixels)?
Steve

Perrone Ford · December 22nd, 2008, 02:21 PM

Quote:

Originally Posted by Steve Phillipps

Is that actually correct Craig, surely at 720/60P you've got the same amount of data as 1080/30P (ie twice the rate but half the pixels)?
Steve

720/60P is not overcrank in the sense of slow-quick motion. It's still a 35mbps VBR which is why SDHC can do it. Overcranking to 60p in slow and quick motion is different.

Steve Phillipps · December 22nd, 2008, 02:29 PM

Sorry Craig, misunderstood what you were saying, I have heard that the SQ Motion uses higher rate than 720/60P.
Steve

Keith Moreau · December 22nd, 2008, 10:35 PM

I think what you were asking is:

Optical Flow Slo Mo (like in Apple Motion) at 1080P vs in Camera at 720P

I've done a bit of this on the EX1 with 1080P 30P. If the original image quality is good, and there isn't too much motion blur in the footage, you can get pretty good slo mo up to 1/2 speed. The resultant images are 1080P, which is quite a bit higher res than 720.

I haven't tried 720P 60P normal acquisition and changing that to slo mo in post by putting that video into a slower framerate timeline. I guess is you shot everything at 720P then you could decide on a 24P or 30P timeline and then decide what footage you wanted slow mo. Seems there might be workflow issue for the non-slowed footage, such as sound. Not sure about that.

I don't usually shoot 1080P with the intention of slowing it down. The optical flow process takes a really long time, and I have one of the fastest systems you can get right now and internal RAID 0, and it still takes a long time for just a few seconds. It also takes an immense amount of hard drive space for the optical flow software to create it's interpolation data. I usually will use the optical flow when I realize I need a pan to take longer, or I something I found would work better in slomo that I didn't plan for in the field. It's just not all that convenient.

When I plan for slomo, I do it with 720P S&Q settings in the EX1.

The thing about optical flow is that ideally you want the shutter to be fast, like 1/250 of a second of faster, so there is very little motion blur so that the optical flow has better edges to work with and can interpolate the in-between frames more accurately. If there is a lot of non-linear movement between frames, which there might be at 1080 30P, optical flow will not know what to do and will make some whacky guesses. An example is a dog fight that I happened to capture when I was at a dog park. When I looked at it later, the action was so fast that I needed to slow it down. I tried to use Motion's optical flow to slow it down. It interpolated and morphed the dog's limbs and movement into strange, unnatural swirly things. This was because of the distance between frames (I was shooting 30P), the texture of the dog fur, and the motion blur because I was using normal shutter speeds.

So, if you can plan, and you want to do all this in post, you can shoot 1080P, make sure the shutter speed is fast, that the motion of what you're capturing isn't too complex, and indeed you will have a higher-res slomo after spending a lot of post processing time on it. Theoretically it might be sharper.

Or you could shoot 720P slo-mo with S&Q and get pretty high-bitrate slomo. You could uprez (using optical flow) and sharpen in post and get an image similar to 1080P but with more natural motion.

I hope this helps.

Joey Daoud · September 26th, 2009, 09:55 AM

I did a few EX1 slow motion tests at various settings, with some side-by-side comparisons. 720p with S&Q at 60 is by far the best and smoothest.

Sony EX1 Slow Motion Test on Vimeo

Craig Seeman · September 26th, 2009, 10:17 AM

shooting 720p24/60 will be slower than 720p30/60 of course but obviously your timeline timebase will influence your choice.

On the Mac one can shoot 720p60 (normal) and use Cinema Tools to reflag it as 30p/60 or 24p/60 and your still getting a "true" rather than "blended" or "interpolated" slow motion. One might have to convert to an I Frame codec such as ProRes for Cinema Tools to handle it.

Annen James · March 24th, 2010, 10:37 AM

So are we all agreeing that it's 720/30p S&Q to 60fps, shutter 1/250th and higher?

Sverker Hahn · March 24th, 2010, 02:19 PM

When shooting (video ...) flying birds and not wanting slomo playback, I sometimes shoot 720/50p, which seems to give smoother movements. All wingbeats will be shown with twice as many pictures.

Will I get strange results if I put this footage on on DVD, having it broadcasted or something like that?

If I slow such footage down in post, will it be of noticably inferior quality than if recorded in slomo 50p?

Robert Bobson · March 9th, 2013, 12:21 PM

I did a test where I shot a scene at 1080 30p and the same scene at 720 60p. I then edited them both into a 1080 project, and the 720 (enlarged to 1080) was noticeably softer.

So I can't see using the sony's slo-mo in a full HD production.

March 9th, 2013, 12:21 PM	#29
Robert Bobson Major Player Join Date: Feb 2003 Location: Bay City, Michigan Posts: 585	Re: How to get best quality EX1 Slow Motion? I did a test where I shot a scene at 1080 30p and the same scene at 720 60p. I then edited them both into a 1080 project, and the 720 (enlarged to 1080) was noticeably softer. So I can't see using the sony's slo-mo in a full HD production.

December 22nd, 2008, 01:30 PM	#16
Steve Phillipps Inner Circle Join Date: Apr 2006 Location: Wales Posts: 2,130	Yes, that's the easiest way to do it - you mean with the SQ Motion function in the menus yes? In this way you can also view it at slomo speed straight off in-camera, something you couldn't even do with the old Varicams! Steve

December 22nd, 2008, 01:55 PM	#19
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Overcrank in camera runs at much higher data rate so when played back at your target speed, you get real (not synthesized) frames at 35mbps VBR. In fact that high data rate is why SDHC and Sony hard drive can't do overcrank to max frame rate (apparently due Sony's built in USB limit though). I think real frames are better than synthesized frames otherwise Phantom cameras would rent for so much.

December 22nd, 2008, 01:58 PM	#20
Steve Phillipps Inner Circle Join Date: Apr 2006 Location: Wales Posts: 2,130	Is that actually correct Craig, surely at 720/60P you've got the same amount of data as 1080/30P (ie twice the rate but half the pixels)? Steve

December 22nd, 2008, 02:29 PM	#23
Steve Phillipps Inner Circle Join Date: Apr 2006 Location: Wales Posts: 2,130	Sorry Craig, misunderstood what you were saying, I have heard that the SQ Motion uses higher rate than 720/60P. Steve

December 22nd, 2008, 10:35 PM	#24
Keith Moreau Major Player Join Date: Nov 2006 Location: Brisbane, California Posts: 530	I think what you were asking is: Optical Flow Slo Mo (like in Apple Motion) at 1080P vs in Camera at 720P I've done a bit of this on the EX1 with 1080P 30P. If the original image quality is good, and there isn't too much motion blur in the footage, you can get pretty good slo mo up to 1/2 speed. The resultant images are 1080P, which is quite a bit higher res than 720. I haven't tried 720P 60P normal acquisition and changing that to slo mo in post by putting that video into a slower framerate timeline. I guess is you shot everything at 720P then you could decide on a 24P or 30P timeline and then decide what footage you wanted slow mo. Seems there might be workflow issue for the non-slowed footage, such as sound. Not sure about that. I don't usually shoot 1080P with the intention of slowing it down. The optical flow process takes a really long time, and I have one of the fastest systems you can get right now and internal RAID 0, and it still takes a long time for just a few seconds. It also takes an immense amount of hard drive space for the optical flow software to create it's interpolation data. I usually will use the optical flow when I realize I need a pan to take longer, or I something I found would work better in slomo that I didn't plan for in the field. It's just not all that convenient. When I plan for slomo, I do it with 720P S&Q settings in the EX1. The thing about optical flow is that ideally you want the shutter to be fast, like 1/250 of a second of faster, so there is very little motion blur so that the optical flow has better edges to work with and can interpolate the in-between frames more accurately. If there is a lot of non-linear movement between frames, which there might be at 1080 30P, optical flow will not know what to do and will make some whacky guesses. An example is a dog fight that I happened to capture when I was at a dog park. When I looked at it later, the action was so fast that I needed to slow it down. I tried to use Motion's optical flow to slow it down. It interpolated and morphed the dog's limbs and movement into strange, unnatural swirly things. This was because of the distance between frames (I was shooting 30P), the texture of the dog fur, and the motion blur because I was using normal shutter speeds. So, if you can plan, and you want to do all this in post, you can shoot 1080P, make sure the shutter speed is fast, that the motion of what you're capturing isn't too complex, and indeed you will have a higher-res slomo after spending a lot of post processing time on it. Theoretically it might be sharper. Or you could shoot 720P slo-mo with S&Q and get pretty high-bitrate slomo. You could uprez (using optical flow) and sharpen in post and get an image similar to 1080P but with more natural motion. I hope this helps.

September 26th, 2009, 09:55 AM	#25
Joey Daoud Tourist Join Date: Sep 2009 Location: Miami Beach, FL Posts: 3	I did a few EX1 slow motion tests at various settings, with some side-by-side comparisons. 720p with S&Q at 60 is by far the best and smoothest. Sony EX1 Slow Motion Test on Vimeo

September 26th, 2009, 10:17 AM	#26
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	shooting 720p24/60 will be slower than 720p30/60 of course but obviously your timeline timebase will influence your choice. On the Mac one can shoot 720p60 (normal) and use Cinema Tools to reflag it as 30p/60 or 24p/60 and your still getting a "true" rather than "blended" or "interpolated" slow motion. One might have to convert to an I Frame codec such as ProRes for Cinema Tools to handle it.

March 24th, 2010, 10:37 AM	#27
Annen James Regular Crew Join Date: Sep 2009 Location: Ogden Posts: 161	So are we all agreeing that it's 720/30p S&Q to 60fps, shutter 1/250th and higher?

March 24th, 2010, 02:19 PM	#28
Sverker Hahn Regular Crew Join Date: Jun 2008 Location: Stockholm, Sweden Posts: 157	When shooting (video ...) flying birds and not wanting slomo playback, I sometimes shoot 720/50p, which seems to give smoother movements. All wingbeats will be shown with twice as many pictures. Will I get strange results if I put this footage on on DVD, having it broadcasted or something like that? If I slow such footage down in post, will it be of noticably inferior quality than if recorded in slomo 50p?