getting good smooth slow motion shots? at DVinfo.net

Scot Anderson · November 20th, 2007, 11:19 PM

ok i am having trouble getting very smooth slow motion in fcp. all ive done is just deinterlace then slow it down, is there anyway i can get it really smooth? i have a vx2100 and i always shoot at 60 fps
i shoot mostly skiing and snowboarding, and the shots i want arent that slowed down, like 60% at the most, usually 75-90.
and i also want to get a shot of a gun action when its shooting, so like the slide going back or the shells coming out etc. so for that would i just shoot it at a high shutter speed? like 500+?

John Moon · November 21st, 2007, 08:26 AM

Scott:
Shooting 60i at a high shutter speed will give you better slow motion. Using After Effects can also help you achieve the slow mo look you are looking for, provided you have AE. If not, I would try a shutter speed at 250 range and go up from there if you have sufficient lighting.

John

Nick Weeks · November 21st, 2007, 03:05 PM

For what its worth Apple Shake and Twixtor both work pretty well with slowmo, although I find Shake's feature very confusing to work with. I always used them on 60i footage shot at 1/60 with very nice results. Not sure about faster shutter speeds

Dylan Pank · November 21st, 2007, 05:42 PM

Don't deinterlace... Make sure that the footage is set up as interlace lower field. Make sure frame blending is set on.

Putting the shutter speed to 120/sec or higher does reduce motion blur, and makes the slow motion seem slightly clearer and less smudgy (and in my opinion better) as we're not used to seeing 360 degree motion blur on footage slower than 60i or 50i. Shooting 50% slow mo at 60/sec is like shooting 30p at 30/sec shutter. Going any higher will just introduce the same fast shutter effects that shooting at high shutter speed always introduces, but that might be cool for an extreme sports style.

Alternatively you could run all your slow mo footage through something like JES de-interlacer...

I think the gun shot you're talking about requires special equipment, it's the sort of thing that would require 120 fps at least. Your video camera is always shooting at 60 fields per second, unless you set the shutter speed slower.

Scot Anderson · November 22nd, 2007, 01:05 AM

Quote:

Originally Posted by Dylan Pank

Don't deinterlace... Make sure that the footage is set up as interlace lower field. Make sure frame blending is set on.

Putting the shutter speed to 120/sec or higher does reduce motion blur, and makes the slow motion seem slightly clearer and less smudgy (and in my opinion better) as we're not used to seeing 360 degree motion blur on footage slower than 60i or 50i. Shooting 50% slow mo at 60/sec is like shooting 30p at 30/sec shutter. Going any higher will just introduce the same fast shutter effects that shooting at high shutter speed always introduces, but that might be cool for an extreme sports style.

Alternatively you could run all your slow mo footage through something like JES de-interlacer...

I think the gun shot you're talking about requires special equipment, it's the sort of thing that would require 120 fps at least. Your video camera is always shooting at 60 fields per second, unless you set the shutter speed slower.

at my school someone got a somewhat slow motion shot of a gun, thats where i got the idea, and he was either using a vx2000 or a gl2. it was really crisp too, hardly any bluring.

Timothy D. Allen · November 22nd, 2007, 02:45 AM

Correct me if I'm wrong, but shooting at 60i is not 60 frames per second. It's 60 fields per second. Which means, when it's all said and done it's still only 30 frames per second. In order to really do this well you'll need a camera that can capture at least 60 full progressive frames per second.

And to piggy back off of Nick's comment, Apple's Shake has an amazing ability to interpret frames that don't exist and produce incredibly smooth slow motion. The interface is quite different than most, but once you learn it, it really makes more sense.

Anyway, hope that helps... (?)

Dylan Pank · November 22nd, 2007, 08:06 AM

Tim, you're not wring as such, but The 2 fields in 60i video can each be mapped to a progressive frame to give you smooth 50% speed slow motion at 30p, but of course you'll lose vertical resolution, as you would with normal field doubling de-interlacing.

There's a good demo on the JES deinterlacer page in the difference of an iMovie slow mo (deinterlaces and then slows down to 15fps playback, looks jerky) and true field to frame slow mo (ie 60i gets turned into 30p field-to-frame, as smooth as film overcranking).

JES does a pretty good job of adaptive pixel matching to get you SOME of the detail back.

Timothy D. Allen · November 22nd, 2007, 10:53 PM

But that would mean that I should be able to shoot at 30p and get slow motion? That doesn't really make much sense. I'll check out the article, and maybe I'm just missing something.

Thanks, Dylan.

Dylan Pank · November 23rd, 2007, 08:41 AM

Quote:

Originally Posted by Timothy D. Allen

But that would mean that I should be able to shoot at 30p and get slow motion? That doesn't really make much sense. I'll check out the article, and maybe I'm just missing something.

Thanks, Dylan.

No. I didn't make myself clear.

Shoot 60i and you can create 30p slow mo in post.

Timothy D. Allen · November 23rd, 2007, 12:59 PM

I get it. I'd be interested in seeing footage of this. Seems like the loss of resolution would be unbearable.

Tom Hardwick · November 23rd, 2007, 01:20 PM

Unlike John, my recommendation is to use your default shutter speed (1/50th here in PAL land) and interlace. Slowing down the footage by half means making every field into a frame, and with so little info to work with, don't up the shutter speed and delete information at source.

The Canopus Speed Control shows why it's important to shoot at the default shutter speed. With the CSC you can slow footage on a sine wave, going from normal speed gently down to a still frame, say. As the still frame is reached individual fields are blended together, and if they're 'sharp' (from using a high shutter speed) this blending just looks jerky.

tom.

November 20th, 2007, 11:19 PM	#1
Scot Anderson Regular Crew Join Date: Jul 2007 Location: fort collins, colorado Posts: 29	getting good smooth slow motion shots? ok i am having trouble getting very smooth slow motion in fcp. all ive done is just deinterlace then slow it down, is there anyway i can get it really smooth? i have a vx2100 and i always shoot at 60 fps i shoot mostly skiing and snowboarding, and the shots i want arent that slowed down, like 60% at the most, usually 75-90. and i also want to get a shot of a gun action when its shooting, so like the slide going back or the shells coming out etc. so for that would i just shoot it at a high shutter speed? like 500+?

November 21st, 2007, 08:26 AM	#2
John Moon Major Player Join Date: Mar 2006 Location: Indianapolis, IN Posts: 446	Scott: Shooting 60i at a high shutter speed will give you better slow motion. Using After Effects can also help you achieve the slow mo look you are looking for, provided you have AE. If not, I would try a shutter speed at 250 range and go up from there if you have sufficient lighting. John __________________ John J. Moon www.northernlightfilmworks.com - Event DV Top 25 Recipient

November 22nd, 2007, 02:45 AM	#6
Timothy D. Allen Regular Crew Join Date: Nov 2006 Location: Chandler, AZ Posts: 86	Correct me if I'm wrong, but shooting at 60i is not 60 frames per second. It's 60 fields per second. Which means, when it's all said and done it's still only 30 frames per second. In order to really do this well you'll need a camera that can capture at least 60 full progressive frames per second. And to piggy back off of Nick's comment, Apple's Shake has an amazing ability to interpret frames that don't exist and produce incredibly smooth slow motion. The interface is quite different than most, but once you learn it, it really makes more sense. Anyway, hope that helps... (?) __________________ Timothy D. Allen http://www.tribaliris.com

November 22nd, 2007, 10:53 PM	#8
Timothy D. Allen Regular Crew Join Date: Nov 2006 Location: Chandler, AZ Posts: 86	But that would mean that I should be able to shoot at 30p and get slow motion? That doesn't really make much sense. I'll check out the article, and maybe I'm just missing something. Thanks, Dylan. __________________ Timothy D. Allen http://www.tribaliris.com

November 23rd, 2007, 12:59 PM	#10
Timothy D. Allen Regular Crew Join Date: Nov 2006 Location: Chandler, AZ Posts: 86	I get it. I'd be interested in seeing footage of this. Seems like the loss of resolution would be unbearable. __________________ Timothy D. Allen http://www.tribaliris.com

November 21st, 2007, 03:05 PM	#3
Nick Weeks Major Player Join Date: Jan 2006 Location: Birmingham, AL USA Posts: 722	For what its worth Apple Shake and Twixtor both work pretty well with slowmo, although I find Shake's feature very confusing to work with. I always used them on 60i footage shot at 1/60 with very nice results. Not sure about faster shutter speeds

November 21st, 2007, 05:42 PM	#4
Dylan Pank Major Player Join Date: Nov 2004 Location: Portsmouth, UK Posts: 611	Don't deinterlace... Make sure that the footage is set up as interlace lower field. Make sure frame blending is set on. Putting the shutter speed to 120/sec or higher does reduce motion blur, and makes the slow motion seem slightly clearer and less smudgy (and in my opinion better) as we're not used to seeing 360 degree motion blur on footage slower than 60i or 50i. Shooting 50% slow mo at 60/sec is like shooting 30p at 30/sec shutter. Going any higher will just introduce the same fast shutter effects that shooting at high shutter speed always introduces, but that might be cool for an extreme sports style. Alternatively you could run all your slow mo footage through something like JES de-interlacer... I think the gun shot you're talking about requires special equipment, it's the sort of thing that would require 120 fps at least. Your video camera is always shooting at 60 fields per second, unless you set the shutter speed slower.

November 22nd, 2007, 08:06 AM	#7
Dylan Pank Major Player Join Date: Nov 2004 Location: Portsmouth, UK Posts: 611	Tim, you're not wring as such, but The 2 fields in 60i video can each be mapped to a progressive frame to give you smooth 50% speed slow motion at 30p, but of course you'll lose vertical resolution, as you would with normal field doubling de-interlacing. There's a good demo on the JES deinterlacer page in the difference of an iMovie slow mo (deinterlaces and then slows down to 15fps playback, looks jerky) and true field to frame slow mo (ie 60i gets turned into 30p field-to-frame, as smooth as film overcranking). JES does a pretty good job of adaptive pixel matching to get you SOME of the detail back.

November 23rd, 2007, 01:20 PM	#11
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Unlike John, my recommendation is to use your default shutter speed (1/50th here in PAL land) and interlace. Slowing down the footage by half means making every field into a frame, and with so little info to work with, don't up the shutter speed and delete information at source. The Canopus Speed Control shows why it's important to shoot at the default shutter speed. With the CSC you can slow footage on a sine wave, going from normal speed gently down to a still frame, say. As the still frame is reached individual fields are blended together, and if they're 'sharp' (from using a high shutter speed) this blending just looks jerky. tom.