Frame Mode and Slo-motion at DVinfo.net

Travis Cossel · April 5th, 2004, 11:47 AM

I've read a number of posts on these forums regarding problems with Frame Mode (I'm on GL2's) and slo-motion in post. I ran a test this weekend, with Frame Mode on a GL2 and then applied a 50% slo-motion in FCP. I had no problems whatsoever. Not that this is a definitive test or anything, but there you have it.

Mark Jefferson · April 5th, 2004, 02:51 PM

I believe that FCP can interpolate frames when you do slowmo. Adobe Premiere 6.5 used the two fields of the video to generate slowmo. If you slow the footage down below 50%, the video gets choppy. I think that Premiere Pro uses frame interpolation, but I'm not sure about that because I only have AP6.5. After Effects can also interpolate frames, and has variable time re-mapping.

Rich Lee · April 8th, 2004, 01:44 AM

Travis, most of my slomo stuff has used reelsmart twixtor. i think for the most part you should be successfull doing a 50% slowdown on your footage without to many artifacts using frame blending. but it really comes down to what is going on in the frame. fast moving objects or quick pans or jolts throw the software. i have had some nice stuff happin using frame mode and taking the slomo effect all the way down to 10% in twixtor. i was amazed how well it worked. but, again, my composition had no foreground or fast moving elememts to throw it off. i would try doing some tests to see what works bests. i recently did a shoot just thinking i could throw anything at it, only to discover that i was dead wrong. now i need to reshoot because of a foreground obect moving to quickly in frame causing major artifacts.

on the other hand, i have messed with shooting interlaced, and using reelsmart fields kit to pull the fields apart into whole frames. the best u can get form this is a 50slow down. the motion was pretty damn good. it did seem to leave little jaggies in the highlights, but it might be exceptable.

these plugins are kinda pricy though. hope it helps a bit.

Travis Cossel · April 12th, 2004, 10:51 PM

Interesting. Well, the test that I did with frame-mode and slo-mo was to simply have my dog chase the camera in a tight circle. So there was definately some motion in the image, although most of the movement would be considered background movement. I didn't see any breakdown at 50% speed in the background. I'm curious now, though.

Maybe I'll rerun the test and have something pass quickly, close in the foreground, and then see how 50% looks. Thanks for the info.

Frank Ladner · April 13th, 2004, 10:36 AM

Have you tried using masks in Twixtor?

A good solution, if you can afford it (I've only played with the demo version), is Realviz Retimer. I have tested it against Twixtor and it is noticeably more precise on faster moving objects. Retimer comes with a separate plugin that you use to paint red and green masks over your footage, to show it exactly what parts are moving in what direction and how quickly. You then take that and use it in the retiming plugin for nice results.

Another thing: I generally always shoot in Frame Mode on my GL2, but if I know a shot is going to wind up in slow-mo, I shoot it interlaced. I do this because I can then take the 60 fields and run them through Revisionfx's FieldsKit->Deinterlacer to get 60 full high quality frames. Now I have more frames to play with. It's like starting a slow-mo sequence with overcranked footage.

,Frank

Travis Cossel · April 15th, 2004, 09:06 AM

I don't have Twixtor, and so far, I haven't seen the need for it. I'm playing in and shooting some footage at a racquetball tournament this weekend, so I should have a chance to get some faster foreground footage and see how it looks slo-mo in frame-mode.

Thomas Smet · April 27th, 2004, 09:52 AM

You can do slow motion on 24P footage you just need a higher end tool than an editing program. ILM did slow motion tests on the 24P footage from Attack of the Clones and they said it looked almost as good as having a film camera over cranked.

Yohann Kouam · May 6th, 2004, 04:04 PM

you can also do ramped slow mo with AE

Jonathon Wilson · May 6th, 2004, 04:14 PM

If I know ahead of time that I will be altering the time of a shot, I've had better luck by lowering the shutter-speed very low so as to remove as much in-frame motion blur as possible. Virtually all of these timing-adjuster tools allow you to then re-insert motion blur across the interpolated frames. You get better interpolation from non-blurred sources.

Frank Ladner · May 7th, 2004, 07:19 AM

Jonathon: I agree. The best way to shoot footage intended for slow-mo/overcrank simulation is to shoot with a really fast shutter. And, as you said, a lot of these tools can add motion blur to the footage.

If you slow down footage with existing motion blur, it just looks funny as everything is moving slow, but the blur is still present. Thus it wouldn't look 'overcranked', but just 'slowed down'.

Additionally, any footage intended to be sped up in post, I believe, should be shot with a longer shutter speed (1/15, etc), allowing for motion blur.

April 5th, 2004, 11:47 AM	#1
Travis Cossel Inner Circle Join Date: Jan 2004 Location: Miami, FL Posts: 2,933	Frame Mode and Slo-motion I've read a number of posts on these forums regarding problems with Frame Mode (I'm on GL2's) and slo-motion in post. I ran a test this weekend, with Frame Mode on a GL2 and then applied a 50% slo-motion in FCP. I had no problems whatsoever. Not that this is a definitive test or anything, but there you have it. __________________ Black Label Films www.blacklabelweddingfilms.com

April 8th, 2004, 01:44 AM	#3
Rich Lee Regular Crew Join Date: Jan 2004 Location: Los Angeles Ca Posts: 126	Travis, most of my slomo stuff has used reelsmart twixtor. i think for the most part you should be successfull doing a 50% slowdown on your footage without to many artifacts using frame blending. but it really comes down to what is going on in the frame. fast moving objects or quick pans or jolts throw the software. i have had some nice stuff happin using frame mode and taking the slomo effect all the way down to 10% in twixtor. i was amazed how well it worked. but, again, my composition had no foreground or fast moving elememts to throw it off. i would try doing some tests to see what works bests. i recently did a shoot just thinking i could throw anything at it, only to discover that i was dead wrong. now i need to reshoot because of a foreground obect moving to quickly in frame causing major artifacts. on the other hand, i have messed with shooting interlaced, and using reelsmart fields kit to pull the fields apart into whole frames. the best u can get form this is a 50slow down. the motion was pretty damn good. it did seem to leave little jaggies in the highlights, but it might be exceptable. these plugins are kinda pricy though. hope it helps a bit. __________________ Rich Lee http://www.rich-lee.com

April 12th, 2004, 10:51 PM	#4
Travis Cossel Inner Circle Join Date: Jan 2004 Location: Miami, FL Posts: 2,933	Interesting. Well, the test that I did with frame-mode and slo-mo was to simply have my dog chase the camera in a tight circle. So there was definately some motion in the image, although most of the movement would be considered background movement. I didn't see any breakdown at 50% speed in the background. I'm curious now, though. Maybe I'll rerun the test and have something pass quickly, close in the foreground, and then see how 50% looks. Thanks for the info. __________________ Black Label Films www.blacklabelweddingfilms.com

April 15th, 2004, 09:06 AM	#6
Travis Cossel Inner Circle Join Date: Jan 2004 Location: Miami, FL Posts: 2,933	I don't have Twixtor, and so far, I haven't seen the need for it. I'm playing in and shooting some footage at a racquetball tournament this weekend, so I should have a chance to get some faster foreground footage and see how it looks slo-mo in frame-mode. __________________ Black Label Films www.blacklabelweddingfilms.com

April 5th, 2004, 02:51 PM	#2
Mark Jefferson Regular Crew Join Date: Jul 2003 Location: Collinsville, Illinois Posts: 86	I believe that FCP can interpolate frames when you do slowmo. Adobe Premiere 6.5 used the two fields of the video to generate slowmo. If you slow the footage down below 50%, the video gets choppy. I think that Premiere Pro uses frame interpolation, but I'm not sure about that because I only have AP6.5. After Effects can also interpolate frames, and has variable time re-mapping.

April 13th, 2004, 10:36 AM	#5
Frank Ladner Major Player Join Date: Aug 2003 Location: Poplarville, MS Posts: 453	Have you tried using masks in Twixtor? A good solution, if you can afford it (I've only played with the demo version), is Realviz Retimer. I have tested it against Twixtor and it is noticeably more precise on faster moving objects. Retimer comes with a separate plugin that you use to paint red and green masks over your footage, to show it exactly what parts are moving in what direction and how quickly. You then take that and use it in the retiming plugin for nice results. Another thing: I generally always shoot in Frame Mode on my GL2, but if I know a shot is going to wind up in slow-mo, I shoot it interlaced. I do this because I can then take the 60 fields and run them through Revisionfx's FieldsKit->Deinterlacer to get 60 full high quality frames. Now I have more frames to play with. It's like starting a slow-mo sequence with overcranked footage. ,Frank

April 27th, 2004, 09:52 AM	#7
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	You can do slow motion on 24P footage you just need a higher end tool than an editing program. ILM did slow motion tests on the 24P footage from Attack of the Clones and they said it looked almost as good as having a film camera over cranked.

May 6th, 2004, 04:04 PM	#8
Yohann Kouam Regular Crew Join Date: May 2004 Location: sevilla Posts: 116	you can also do ramped slow mo with AE

May 6th, 2004, 04:14 PM	#9
Jonathon Wilson Regular Crew Join Date: Feb 2004 Location: Austin, TX Posts: 182	If I know ahead of time that I will be altering the time of a shot, I've had better luck by lowering the shutter-speed very low so as to remove as much in-frame motion blur as possible. Virtually all of these timing-adjuster tools allow you to then re-insert motion blur across the interpolated frames. You get better interpolation from non-blurred sources.

May 7th, 2004, 07:19 AM	#10
Frank Ladner Major Player Join Date: Aug 2003 Location: Poplarville, MS Posts: 453	Jonathon: I agree. The best way to shoot footage intended for slow-mo/overcrank simulation is to shoot with a really fast shutter. And, as you said, a lot of these tools can add motion blur to the footage. If you slow down footage with existing motion blur, it just looks funny as everything is moving slow, but the blur is still present. Thus it wouldn't look 'overcranked', but just 'slowed down'. Additionally, any footage intended to be sped up in post, I believe, should be shot with a longer shutter speed (1/15, etc), allowing for motion blur.