More Slow Motion questions at DVinfo.net

Luis Otero · March 14th, 2006, 11:02 PM

Hello community of geniouses:

I have a potential client that asked me for some tests for slow motion for a music video project that will contain 85% slow motion and 15 % regular footage. I performed two of them: HD in 24P and SD in 60P. He wanted to do it in 16mm, but a common friend that has done some works with me told him that the HD-100 will give him what he wants or exceeds in terms of resolution/visual performance. Plus, no messing arround with film, development cost, etc.

Without a doubt, the HD looks much more "high definition", but too strobbing when slowered down to 60%. SD was GREAT, but was, well, just SD... We are trying to compete with 16mm film. By the way, he was extremely impressed with the resolution and he is sold on HDV!

His project cannot afford the HD-SDI card route. Any other trial already done by anybody that can be shared as to how to get a better Slow Motion performance using HD? One test I did not performed, but by logic will yield better results, will be HD 30P, but I do not think it will give us the clean result 60P gave. Any comments are very welcommed, including parameters for shutter speed!

Luis Otero

Tim Dashwood · March 14th, 2006, 11:24 PM

If it is a music video, then HDV-SD60P shouldn't be an issue. MTV doesn't broadcast HD yet do they?

Shooting 30P will give you a 80% slow-motion speed when you bring it back to 24fps. 60P gives you 40% slow-motion speed when you bring it back to 24fps.

As a general rule, set your shutter speed to at least 1/100 (preferably 1/120)when shooting 60P. The higher the shutter speed, the sharper the image.
For a contemporary music video "no-motion blur" look I would probably recommend at least 1/200 for 60P, and 1/100 for 24P.

Luis Otero · March 14th, 2006, 11:32 PM

Tim,

Thanks for your always sharp and clear advice!

Luis

Paolo Ciccone · March 15th, 2006, 09:26 AM

Luis.

What about shooting the slowmo in 50P, it will give you 20% more resolution (576 lines instead of 480) and resolves to exactly 50% speed when played at 24fps.

--
Paolo

Tim Dashwood · March 15th, 2006, 10:25 AM

Quote:

Originally Posted by Paolo Ciccone

Luis.

What about shooting the slowmo in 50P, it will give you 20% more resolution (576 lines instead of 480) and resolves to exactly 50% speed when played at 24fps.

--
Paolo

I forgot to mention 50P. It works well too. However Luis, if you are to use HMI or Kino-Flo lighting, make sure you dial in 1/60 or 1/120 shutter speed when using 50P to avoid flicker. Puerto Rico is a 60Hz region right?

Laszlo Horvath · March 15th, 2006, 12:50 PM

Quote:

Originally Posted by Tim Dashwood

I forgot to mention 50P. It works well too. However Luis, if you are to use HMI or Kino-Flo lighting, make sure you dial in 1/60 or 1/120 shutter speed when using 50P to avoid flicker. Puerto Rico is a 60Hz region right?

So, this 720p/50 working in Canada too? I mean insight in the hall. If yes, which sutter speed I need to use?
Also outside, where I don't use any light, it's OK to shoot 50p?

Tim, please let me know.

LaszloNo flickering?

Tim Gray · March 15th, 2006, 12:57 PM

I would imagine that flickering with 50p has to do with electricity running at 60Hz in some countries. Thus you should be fine with 50p outside since the sun isn't 60Hz.

Tim Holtermann · March 15th, 2006, 02:13 PM

Have you tried taking your 24P (30P would be better if going HD) and slowing it down with After Effects using time remapping? The slow motion you get in editing doesn't compare to the same effect done in programs designed to re-time footage.

Tim Dashwood · March 15th, 2006, 02:44 PM

Quote:

Originally Posted by Laszlo Horvath

So, this 720p/50 working in Canada too? I mean insight in the hall. If yes, which sutter speed I need to use?
Also outside, where I don't use any light, it's OK to shoot 50p?

Tim, please let me know.

LaszloNo flickering?

Yeah it works fine. As Tim Gray said, outside with sunlight wouldn't make a difference. Tungsten lighting should be fine as well.
However, if you are shooting 25P or 50P while using HMI or flourescent lighting in Canada/U.S. or other 60Hz regions, then set your shutter to variable, and then adjust it to 1/60 (1/59.92 or 1/60.01) or 1/120 (1/120.1 or 1/119.4).

Laszlo Horvath · March 15th, 2006, 03:18 PM

Thanks guys!

Laszlo

Luis Otero · March 15th, 2006, 05:58 PM

Quote:

Originally Posted by Tim Holtermann

Have you tried taking your 24P (30P would be better if going HD) and slowing it down with After Effects using time remapping? The slow motion you get in editing doesn't compare to the same effect done in programs designed to re-time footage.

Tim,

Thanks for this information, and thanks to everybody else for taking their time and providing your input.

As to AE, I never have done it, so could you please let me know (in general) the steps to do the time remaping using it?

And, yes, Puerto Rico is 60 Hz. The music video, as far as I know, will use tungsten and fire for ilumination (night scenes only), so I am pretty shure no HMI will be used.

Again, thanks for your comments.

Luis

Brian Luce · March 15th, 2006, 06:14 PM

isn't it just easier to apply a filter in post? or is it hard to do that in hdv?

Luis Otero · March 15th, 2006, 07:19 PM

Brian,

As far as I know there is no filter perse for time slow motion effect. You either shoot at higher frame rate and slow it down in post (60fps running at 40% in a 24fps timeframe) or slow down the footage taken in 24fps to 60%. The problem with the second option is that the final product is not as clean as the first option. That is my dilema: the HD-100 does not record to tape 60fps; its highest frame rate is 30fps. In SD it goes to 60fps, but does not give you the 720P, only 480p. If you use the component output with the AJA card, you can get it, but you need to add cost to your production, wich is the opposite of what we are looking for.

If there is a "filter" out there, please let me know since I am trying to experiment with as many solutions as posible for my client.

Thanks,

Luis

PS

I have MotionPerfect from DynaPel, wich expands or contracts footage to conform it to whatever is your desired final frame rate, but the outome footage is kind of funny arround the edges of the fast moving object (kind of rippling water).

Tim Dashwood · March 15th, 2006, 07:39 PM

Quote:

Originally Posted by Luis Otero

If there is a "filter" out there, please let me know since I am trying to experiment with as many solutions as posible for my client.

Twixtor will interpolate frames and create new in-between morphed frames, but it still isn't temporally quite as good as overcranking in the first place. Also, there is a bit of a learning curve with Twixtor. You can download a demo.

Paolo Ciccone · March 15th, 2006, 09:24 PM

Quote:

Originally Posted by Brian Luce

isn't it just easier to apply a filter in post? or is it hard to do that in hdv?

It's not a matter of HDV, the fact is that a software trick will just double the existing frames and it will add some interpolated frames with, possibly, some frame blending. It's OK but it doesn't create the real slow-mo effect. Think of filming a stone being thrown into a lake. The dynamics of the stone hitting the water surface, the water ripples and splashes, all that stuff can't be captured at standard speed and then slowed down effectively. On the other hand, if you overcrank you actually capture more "events", events that you can watch later at slower speed.

Hope this makes sense :)

--
Paolo

March 14th, 2006, 11:02 PM	#1
Luis Otero Major Player Join Date: Apr 2005 Location: Fort Dodge, IA Posts: 221	More Slow Motion questions Hello community of geniouses: I have a potential client that asked me for some tests for slow motion for a music video project that will contain 85% slow motion and 15 % regular footage. I performed two of them: HD in 24P and SD in 60P. He wanted to do it in 16mm, but a common friend that has done some works with me told him that the HD-100 will give him what he wants or exceeds in terms of resolution/visual performance. Plus, no messing arround with film, development cost, etc. Without a doubt, the HD looks much more "high definition", but too strobbing when slowered down to 60%. SD was GREAT, but was, well, just SD... We are trying to compete with 16mm film. By the way, he was extremely impressed with the resolution and he is sold on HDV! His project cannot afford the HD-SDI card route. Any other trial already done by anybody that can be shared as to how to get a better Slow Motion performance using HD? One test I did not performed, but by logic will yield better results, will be HD 30P, but I do not think it will give us the clean result 60P gave. Any comments are very welcommed, including parameters for shutter speed! Luis Otero

March 14th, 2006, 11:24 PM	#2
Tim Dashwood Wrangler Join Date: Aug 2005 Location: Toronto, ON, Canada Posts: 3,637	If it is a music video, then HDV-SD60P shouldn't be an issue. MTV doesn't broadcast HD yet do they? Shooting 30P will give you a 80% slow-motion speed when you bring it back to 24fps. 60P gives you 40% slow-motion speed when you bring it back to 24fps. As a general rule, set your shutter speed to at least 1/100 (preferably 1/120)when shooting 60P. The higher the shutter speed, the sharper the image. For a contemporary music video "no-motion blur" look I would probably recommend at least 1/200 for 60P, and 1/100 for 24P. __________________ Tim Dashwood

March 14th, 2006, 11:32 PM	#3
Luis Otero Major Player Join Date: Apr 2005 Location: Fort Dodge, IA Posts: 221	Tim, Thanks for your always sharp and clear advice! Luis

March 15th, 2006, 09:26 AM	#4
Paolo Ciccone Trustee Join Date: Apr 2005 Location: Santa Cruz, CA Posts: 1,116	Luis. What about shooting the slowmo in 50P, it will give you 20% more resolution (576 lines instead of 480) and resolves to exactly 50% speed when played at 24fps. -- Paolo

March 15th, 2006, 12:57 PM	#7
Tim Gray Regular Crew Join Date: Feb 2006 Location: Media, PA Posts: 144	I would imagine that flickering with 50p has to do with electricity running at 60Hz in some countries. Thus you should be fine with 50p outside since the sun isn't 60Hz.

March 15th, 2006, 02:13 PM	#8
Tim Holtermann Regular Crew Join Date: Feb 2006 Posts: 184	Have you tried taking your 24P (30P would be better if going HD) and slowing it down with After Effects using time remapping? The slow motion you get in editing doesn't compare to the same effect done in programs designed to re-time footage.

March 15th, 2006, 03:18 PM	#10
Laszlo Horvath Major Player Join Date: Oct 2005 Location: LaSalle Ontario Canada Posts: 289 Images: 5	Thanks guys! Laszlo

March 15th, 2006, 06:14 PM	#12
Brian Luce Inner Circle Join Date: Jan 2006 Posts: 2,290	isn't it just easier to apply a filter in post? or is it hard to do that in hdv?

March 15th, 2006, 07:19 PM	#13
Luis Otero Major Player Join Date: Apr 2005 Location: Fort Dodge, IA Posts: 221	Brian, As far as I know there is no filter perse for time slow motion effect. You either shoot at higher frame rate and slow it down in post (60fps running at 40% in a 24fps timeframe) or slow down the footage taken in 24fps to 60%. The problem with the second option is that the final product is not as clean as the first option. That is my dilema: the HD-100 does not record to tape 60fps; its highest frame rate is 30fps. In SD it goes to 60fps, but does not give you the 720P, only 480p. If you use the component output with the AJA card, you can get it, but you need to add cost to your production, wich is the opposite of what we are looking for. If there is a "filter" out there, please let me know since I am trying to experiment with as many solutions as posible for my client. Thanks, Luis PS I have MotionPerfect from DynaPel, wich expands or contracts footage to conform it to whatever is your desired final frame rate, but the outome footage is kind of funny arround the edges of the fast moving object (kind of rippling water).