Slow Motion

Steve Burke · January 12th, 2007, 03:06 AM

Wondering if anyone can help with this....
1) Always used PPro slow motion without any problems.
2) Tried the AE approach, as detailed above....
Findings are as follows:
a) The overall frame brightness and contrast has changed from the original ( noticably slightly darker ) - hence when I import the clip back into PPro, it doesnt 'match' the surrounding clips - same background ( Church wedding )... more worrying is....
b) What I notice is a jitter on the Brides dress detail. I have monitored this in the source monitor and notice that adjacent frames are 'focussed' and 'blurred', hence creating the jitter at slo-mo speed playback.
c) Looking at the clips in the source monitor at 800% mag, I notice the same 'blockiness', hence I dont see how there can be an improvement in the slow motion effect???

I understand PPro uses blending, and AE uses some mathematical algorithm to interpolate the frames..... Just that I have the above probs and was wondering what I was doing wrong / failing to understand...... All comments welcome. Thanks.

Steve Burke · January 12th, 2007, 09:49 AM

Just checking the manual for PPRO.....

To blend frames for smooth motion
Motion in a clip may appear jerky when you change the speed of a clip, or output to a different frame rate. Make sure that frame blending is on to create new interpolated frames that smooth the motion.
Choose Clip > Video Options > Frame Blend.

Does this mean that PPro has interpolation, as the manual suggests it 'creates new interpolated frames' ?????

Your comments are appreciated.

Thanks

Alan James · January 12th, 2007, 05:17 PM

What Premiere calls “interpolation” is really frame blending, I have no idea why Adobe decided to call frame blending “interpolation” because clearly it isn’t. The jitter you are talking about it because of the line interpolation in After Effects. Make sure that you click the check box for “Preserve Edges” in the “interpret footage” menu. This should smooth out most of your problem, but if you are still having some apply a 1 of 2 pixel vertical directional blur. You will loose a slight bit of detail but it will look loads better.

Alan James · January 12th, 2007, 05:31 PM

I was just watching the “Children of Men” HD trailer and I noticed that at 1:39 mins into the trailer they used an interpolation software of some kind to create a slow motion effect. Check it out and be sure to look at their feet, and remember this is a professional trailer that probably cost thousands of dollars to make, and they were as limited as us when it came to creating slow motion. So the trade offs are having a “jelly” effect (seems to describe it well) caused by frame interpolation or lose a little bit of detail by interpolating scan lines.

Scott Di Lalla · January 13th, 2007, 12:47 PM

[QUOTE=Alan James]Scott that was a good idea but its still harder to turn 24 full frames into slow motion then turning 60 half frames into 60 full frames.

Alan, I will definitely try it the way you have explained but I have a few more questions. First, I think my lack of editing and importing video plays a role in how fast I will understand all this. My editing software is FCP Pro HD. Before I ran into this thread, and this may sound a bit redundant, to make scenes in slow motion I would do the following: Shoot in 24p with the shutter boosted up a bit, import it into FCP and just slow the scene down 20-50%. My question is what are the pros and cons to this method and also do things change a bit because I am using FCP?

Alan James · January 13th, 2007, 02:54 PM

FCP uses frame interpolation just like Ppro. When comparing these two methods the only pros I can come up with is that there is no lose in detail in the frames that were actually recorded. The cons outweigh the cons of line interpolation however. Slowing down a clip 50% means two frames have to be blended in order to create a new frame. I have attached an example of an exploding brick wall I made then slowed down with frame blending. Frame 1 is a real frame. Frame 2 is made by blending frame 1 and 3 together, you will notice that there are 2 times as many bricks in it then the others and they are opaque. And Frame 3 is a real frame. Basically Frame 1 and 3 exist in frame 2 but are at 50% opacity.This is the drawback for using frame blending. If I were to have done this the 60i to 60p to 24p way it would have only slightly lost vertical detail, and with the XL2 when you shoot progressively its recommended you turn vertical detail to low anyways, so it would match up great.

One other thing. This works best in After Effects 7 becuase the line interpolation software is better. If you are using an older version on After Effects it wont work as well. One way to improve footage is to just put a larger vertical directional blur on it. This will reduce the flicker effect.

Adam Bray · January 14th, 2007, 10:18 PM

Does anyone have any video samples of the slow motion method Alan has described. I'm curious how it would look compared to some 16mm footage shot at 64 fps.

Alan James · January 15th, 2007, 03:24 AM

Well I can tell you with one hundred percent certainty that if the 16mm is exposed and developed correctly will look better. No doubt about it. I can’t comment on HOW much better it will look being that I don’t know if you are scanning it digitally then outputting from a digital source or making an optical print but it will be a noticeable difference. It will look better mostly because 16mm has higher “resolution” higher latitude and every frame originated from a progressive source. Again it depends on how the 16mm was shot, best shot 16mm at 64fps will look better then the XL2 shooting at 60i converted to 60p.

The celluloid vs. digital discussion is probably best left for another thread, but if anyone wants to further discuss how it pertains to slow motion I would request that we refer to 16mm and 35mm as “celluloid” not “film”. This is a point I have been trying to press amongst my friends and a habit I am trying to get into. A film is the final product not the material. Celluloid and digital (hard drive or tape) are both materials we used to make film. Thanx.

Matt Throop · January 21st, 2007, 02:49 PM

This might be a stupid question, but I don't have Adobe After Effects on my iMac, but I do have Motion 2. I can achieve a good smooth slow mo effect with Motion 2 like you guys are talking about with AE?

Thanks.

Che Butterfield · January 26th, 2007, 12:13 AM

Quote:

Originally Posted by Adam Bray

Does anyone have any video samples of the slow motion method Alan has described. I'm curious how it would look compared to some 16mm footage shot at 64 fps.

http://www.dvinfo.net/conf/showpost....62&postcount=4

Steve Maller · January 26th, 2007, 12:45 PM

I've read somewhere that this technique (60i -> 24p) can be done solely with Final Cut Studio tools (specifically using Cinema Tools to conform 60i to 24p). Does anybody have any thoughts. I'd love to add that kind of thing to my arsenal. I love smooth slo-mo, and it's so bloody hard to do in the digital world.

Scott Di Lalla · February 8th, 2007, 12:33 PM

Quote:

Originally Posted by Steve Maller

I've read somewhere that this technique (60i -> 24p) can be done solely with Final Cut Studio tools (specifically using Cinema Tools to conform 60i to 24p). Does anybody have any thoughts. I'd love to add that kind of thing to my arsenal. I love smooth slo-mo, and it's so bloody hard to do in the digital world.

Yes, I am also curious about Steve's question.

Matthew Jackson · February 16th, 2007, 04:06 PM

Alan - maybe I need to start a new thread for this... but it relates here....

I film billfish, sailfish and marlin... what you're saying is if I'm shooting in 30p.. and I want a good slo mo shot... shoot 60i at 1/60? or 1/(the percentage slower)? Is that right? Also... using PPRO... is it bad to have a 24p project with a few 30p shots rendered into them? I guess... will it all look the same given that I follow the processes correctly, AND maintain quality?

pretty convoluted... sorry. LOL

Matthew Jackson · February 16th, 2007, 04:11 PM

oh... the other point... my older footage is in 30p, so I've been shooting in 30p with my XL2... if I use a shutter speed of 1/300 for billfish jumps, will that have the same effect as shooting in 60i? meaning capture more of the subject? or what benefit does shooting at a really high shutter speed have... it seems to make bites, and things that happen fast a bit clearer... is this correct?

Donovan Cerminara · March 16th, 2007, 02:37 AM

Hey Alan,

I´m about to go out and test your 60i to 24p trick with my XL2. I´d like to add my "voice" to the growing crowd of people.

Thanks very much for the comprehensive tutorial... and I salute your stance on filmmaking.. ie:

"A film is the final product not the material. Celluloid and digital (hard drive or tape) are both materials we used to make film."

Bravo, sir!

January 12th, 2007, 03:06 AM	#16
Steve Burke Regular Crew Join Date: Feb 2006 Location: UK Posts: 63	Wondering if anyone can help with this.... 1) Always used PPro slow motion without any problems. 2) Tried the AE approach, as detailed above.... Findings are as follows: a) The overall frame brightness and contrast has changed from the original ( noticably slightly darker ) - hence when I import the clip back into PPro, it doesnt 'match' the surrounding clips - same background ( Church wedding )... more worrying is.... b) What I notice is a jitter on the Brides dress detail. I have monitored this in the source monitor and notice that adjacent frames are 'focussed' and 'blurred', hence creating the jitter at slo-mo speed playback. c) Looking at the clips in the source monitor at 800% mag, I notice the same 'blockiness', hence I dont see how there can be an improvement in the slow motion effect??? I understand PPro uses blending, and AE uses some mathematical algorithm to interpolate the frames..... Just that I have the above probs and was wondering what I was doing wrong / failing to understand...... All comments welcome. Thanks. __________________ Canon XL2, Photoshop CS2, Premiere Pro 2.0, After Effects 7.0, Encore DVD 2.0, Audition 2.0. 2x PCs both Duo-Core 3GHz, both 1GB RAM, both dual monitor. 1x Laptop, single core, 3GHz, 1GB RAM. Last edited by Steve Burke; January 12th, 2007 at 06:24 AM.

January 12th, 2007, 09:49 AM	#17
Steve Burke Regular Crew Join Date: Feb 2006 Location: UK Posts: 63	Just checking the manual for PPRO..... To blend frames for smooth motion Motion in a clip may appear jerky when you change the speed of a clip, or output to a different frame rate. Make sure that frame blending is on to create new interpolated frames that smooth the motion. Choose Clip > Video Options > Frame Blend. Does this mean that PPro has interpolation, as the manual suggests it 'creates new interpolated frames' ????? Your comments are appreciated. Thanks __________________ Canon XL2, Photoshop CS2, Premiere Pro 2.0, After Effects 7.0, Encore DVD 2.0, Audition 2.0. 2x PCs both Duo-Core 3GHz, both 1GB RAM, both dual monitor. 1x Laptop, single core, 3GHz, 1GB RAM.

January 13th, 2007, 12:47 PM	#20
Scott Di Lalla Regular Crew Join Date: Apr 2006 Location: Los Angeles Posts: 49	[QUOTE=Alan James]Scott that was a good idea but its still harder to turn 24 full frames into slow motion then turning 60 half frames into 60 full frames. Alan, I will definitely try it the way you have explained but I have a few more questions. First, I think my lack of editing and importing video plays a role in how fast I will understand all this. My editing software is FCP Pro HD. Before I ran into this thread, and this may sound a bit redundant, to make scenes in slow motion I would do the following: Shoot in 24p with the shutter boosted up a bit, import it into FCP and just slow the scene down 20-50%. My question is what are the pros and cons to this method and also do things change a bit because I am using FCP? __________________ S. di Lalla http://www.choppertown.net

January 13th, 2007, 02:54 PM	#21
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	FCP uses frame interpolation just like Ppro. When comparing these two methods the only pros I can come up with is that there is no lose in detail in the frames that were actually recorded. The cons outweigh the cons of line interpolation however. Slowing down a clip 50% means two frames have to be blended in order to create a new frame. I have attached an example of an exploding brick wall I made then slowed down with frame blending. Frame 1 is a real frame. Frame 2 is made by blending frame 1 and 3 together, you will notice that there are 2 times as many bricks in it then the others and they are opaque. And Frame 3 is a real frame. Basically Frame 1 and 3 exist in frame 2 but are at 50% opacity.This is the drawback for using frame blending. If I were to have done this the 60i to 60p to 24p way it would have only slightly lost vertical detail, and with the XL2 when you shoot progressively its recommended you turn vertical detail to low anyways, so it would match up great. One other thing. This works best in After Effects 7 becuase the line interpolation software is better. If you are using an older version on After Effects it wont work as well. One way to improve footage is to just put a larger vertical directional blur on it. This will reduce the flicker effect. Attached Thumbnails

January 21st, 2007, 02:49 PM	#24
Matt Throop New Boot Join Date: May 2006 Location: Oshawa, ON, CA Posts: 19	This might be a stupid question, but I don't have Adobe After Effects on my iMac, but I do have Motion 2. I can achieve a good smooth slow mo effect with Motion 2 like you guys are talking about with AE? Thanks. __________________ Canon XL-2 \| Rebel XT iMac 20" 2.0Ghz 2GB RAM 256MB VRAM 500GB HDD

January 12th, 2007, 05:17 PM	#18
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	What Premiere calls “interpolation” is really frame blending, I have no idea why Adobe decided to call frame blending “interpolation” because clearly it isn’t. The jitter you are talking about it because of the line interpolation in After Effects. Make sure that you click the check box for “Preserve Edges” in the “interpret footage” menu. This should smooth out most of your problem, but if you are still having some apply a 1 of 2 pixel vertical directional blur. You will loose a slight bit of detail but it will look loads better.

January 12th, 2007, 05:31 PM	#19
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	I was just watching the “Children of Men” HD trailer and I noticed that at 1:39 mins into the trailer they used an interpolation software of some kind to create a slow motion effect. Check it out and be sure to look at their feet, and remember this is a professional trailer that probably cost thousands of dollars to make, and they were as limited as us when it came to creating slow motion. So the trade offs are having a “jelly” effect (seems to describe it well) caused by frame interpolation or lose a little bit of detail by interpolating scan lines.

January 14th, 2007, 10:18 PM	#22
Adam Bray Major Player Join Date: Sep 2004 Location: Houston/Austin Posts: 394	Does anyone have any video samples of the slow motion method Alan has described. I'm curious how it would look compared to some 16mm footage shot at 64 fps.

January 15th, 2007, 03:24 AM	#23
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	Well I can tell you with one hundred percent certainty that if the 16mm is exposed and developed correctly will look better. No doubt about it. I can’t comment on HOW much better it will look being that I don’t know if you are scanning it digitally then outputting from a digital source or making an optical print but it will be a noticeable difference. It will look better mostly because 16mm has higher “resolution” higher latitude and every frame originated from a progressive source. Again it depends on how the 16mm was shot, best shot 16mm at 64fps will look better then the XL2 shooting at 60i converted to 60p. The celluloid vs. digital discussion is probably best left for another thread, but if anyone wants to further discuss how it pertains to slow motion I would request that we refer to 16mm and 35mm as “celluloid” not “film”. This is a point I have been trying to press amongst my friends and a habit I am trying to get into. A film is the final product not the material. Celluloid and digital (hard drive or tape) are both materials we used to make film. Thanx.

January 26th, 2007, 12:45 PM	#26
Steve Maller Major Player Join Date: Sep 2006 Location: Burlingame, CA USA Posts: 285	I've read somewhere that this technique (60i -> 24p) can be done solely with Final Cut Studio tools (specifically using Cinema Tools to conform 60i to 24p). Does anybody have any thoughts. I'd love to add that kind of thing to my arsenal. I love smooth slo-mo, and it's so bloody hard to do in the digital world. __________________ me@facebook: http://facebook.com/stevemallerphotography

February 16th, 2007, 04:06 PM	#28
Matthew Jackson Regular Crew Join Date: Oct 2006 Location: Fort Worth, Texas Posts: 92	Alan - maybe I need to start a new thread for this... but it relates here.... I film billfish, sailfish and marlin... what you're saying is if I'm shooting in 30p.. and I want a good slo mo shot... shoot 60i at 1/60? or 1/(the percentage slower)? Is that right? Also... using PPRO... is it bad to have a 24p project with a few 30p shots rendered into them? I guess... will it all look the same given that I follow the processes correctly, AND maintain quality? pretty convoluted... sorry. LOL

February 16th, 2007, 04:11 PM	#29
Matthew Jackson Regular Crew Join Date: Oct 2006 Location: Fort Worth, Texas Posts: 92	oh... the other point... my older footage is in 30p, so I've been shooting in 30p with my XL2... if I use a shutter speed of 1/300 for billfish jumps, will that have the same effect as shooting in 60i? meaning capture more of the subject? or what benefit does shooting at a really high shutter speed have... it seems to make bites, and things that happen fast a bit clearer... is this correct?

March 16th, 2007, 02:37 AM	#30
Donovan Cerminara New Boot Join Date: Sep 2005 Location: Vancouver, BC, Canada Posts: 16	All hail Mr. James! Hey Alan, I´m about to go out and test your 60i to 24p trick with my XL2. I´d like to add my "voice" to the growing crowd of people. Thanks very much for the comprehensive tutorial... and I salute your stance on filmmaking.. ie: "A film is the final product not the material. Celluloid and digital (hard drive or tape) are both materials we used to make film." Bravo, sir! __________________ Donovan Cerminara Bull By the Horns Productions bullbythehorns@gmail.com