Resolution drop on Slo Mo ?? at DVinfo.net

Chris Harding · January 24th, 2010, 07:09 AM

Hi Guys

Does anyone know roughly what sort of resolution drop you are likely to get by simply using "ctrl+drag" to make a "slo mo" clip.

I have done a few clips with some slo mo done this way and there definately looks a bit "fuzzier' that standard footage which looks crisp on a 42" LCD TV. Is this an actual resolution loss or somply an optical illusion due to the limited frames Vegas has to work with on the slo mo bit of footage???

Admittedly this was on a DVD so we are talking about SD PAL Widescreen but shot at 1080i and transcoded to SD AVI before editing.

Chris

Edward Troxel · January 24th, 2010, 07:18 AM

It's due to the limited frames Vegas has to work with. If you slow something down by 50%, you've now doubled the frames needed. However, those frame do not exist in the original footage. So they have to be created some way.

You may try turning off resampling or playing with some of the various setting to see if you find a combination you like better.

Richard Hunter · January 24th, 2010, 08:24 AM

The footage is deinterlaced when you apply slo-mo, and this causes a resolution drop.

Richard

Mike Kujbida · January 24th, 2010, 09:26 AM

Quote:

Originally Posted by Richard Hunter

The footage is deinterlaced when you apply slo-mo, and this causes a resolution drop.

Wouldn't it make sense to slo-mo the original HD clip and then render it to SD, thereby keeping SD resolution at it's max?

Chris Harding · January 24th, 2010, 06:03 PM

Thanks Guys

Much appreciated!! If I have to use it then probably Mike's idea is the best but I'll still have to de-interlace the 1080i footage but it will still be better than transcoded SD!

The best results seem to come by forcing a resample

Chris

Mike Kujbida · January 24th, 2010, 07:39 PM

Chris, a lot of Vegas users I know really like Mike Crash's free Smart Deinterlace filter.

Chris Harding · January 24th, 2010, 10:58 PM

Thanks Mike

I see that the "correct" way to do slo mo is to de-interlace and then also set the frame rate (just for the clip you are doing slomo for) to 50fps (for PAL footage) in project properties which reduces the number of frames that Vegas needs to add.

You then render just that clip as a slo mo video out to a lossless AVI and later import your normal project!!

Chris

Richard Hunter · January 25th, 2010, 01:08 AM

Quote:

Originally Posted by Mike Kujbida

Wouldn't it make sense to slo-mo the original HD clip and then render it to SD, thereby keeping SD resolution at it's max?

Hi Mike. If you use Virtualdub for this I would agree, because you have better control over how the deinterlacing and scaling are done. In Vegas, I always seem to get a little bit more softening or fuzziness. But having said that, Vegas is not bad at all and it is much more convenient to use compared with having to grow a beard in order to use Virtualdub.

Richard

Thomas Moore · January 25th, 2010, 05:16 AM

Something like this YouTube - Slow Motion in Sony Vegas might help you...

Chris Harding · January 25th, 2010, 05:31 AM

Hi Thomas

Hey, thanks!! That's a nifty trick indeed!!!and coming from the home of Douglas Spotted Eagle it will be good advice!!!

I'll try that on my next slo mo!!! A lot easier than getting my head around Virtual Dub or making external double frame rate files....it "cheats" a little but who cares if the end result is good???

Much appreciated..I wonder if anyone else has used this tip???

Chris

Thomas Moore · January 25th, 2010, 08:09 AM

Quote:

Originally Posted by Chris Harding

Hi Thomas

Hey, thanks!! That's a nifty trick indeed!!!and coming from the home of Douglas Spotted Eagle it will be good advice!!!

I'll try that on my next slo mo!!! A lot easier than getting my head around Virtual Dub or making external double frame rate files....it "cheats" a little but who cares if the end result is good???

Much appreciated..I wonder if anyone else has used this tip???

Chris

It's not cheating if it works :)

January 24th, 2010, 07:09 AM	#1
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Resolution drop on Slo Mo ?? Hi Guys Does anyone know roughly what sort of resolution drop you are likely to get by simply using "ctrl+drag" to make a "slo mo" clip. I have done a few clips with some slo mo done this way and there definately looks a bit "fuzzier' that standard footage which looks crisp on a 42" LCD TV. Is this an actual resolution loss or somply an optical illusion due to the limited frames Vegas has to work with on the slo mo bit of footage??? Admittedly this was on a DVD so we are talking about SD PAL Widescreen but shot at 1080i and transcoded to SD AVI before editing. Chris

January 24th, 2010, 07:18 AM	#2
Edward Troxel Sponsor: JET DV Join Date: Dec 2001 Location: Southern Illinois Posts: 7,953	It's due to the limited frames Vegas has to work with. If you slow something down by 50%, you've now doubled the frames needed. However, those frame do not exist in the original footage. So they have to be created some way. You may try turning off resampling or playing with some of the various setting to see if you find a combination you like better. __________________ Edward Troxel [SCVU] JETDV Scripts/Scripting Tutorials/Excalibur/Montage Magic/Newsletters

January 24th, 2010, 08:24 AM	#3
Richard Hunter Trustee Join Date: Dec 2004 Location: Lipa City Batangas, Philippines Posts: 1,110	The footage is deinterlaced when you apply slo-mo, and this causes a resolution drop. Richard

January 24th, 2010, 06:03 PM	#5
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Thanks Guys Much appreciated!! If I have to use it then probably Mike's idea is the best but I'll still have to de-interlace the 1080i footage but it will still be better than transcoded SD! The best results seem to come by forcing a resample Chris

January 24th, 2010, 07:39 PM	#6
Mike Kujbida Inner Circle Join Date: May 2005 Location: Windsor, ON Canada Posts: 2,770	Chris, a lot of Vegas users I know really like Mike Crash's free Smart Deinterlace filter.

January 24th, 2010, 10:58 PM	#7
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Thanks Mike I see that the "correct" way to do slo mo is to de-interlace and then also set the frame rate (just for the clip you are doing slomo for) to 50fps (for PAL footage) in project properties which reduces the number of frames that Vegas needs to add. You then render just that clip as a slo mo video out to a lossless AVI and later import your normal project!! Chris

January 25th, 2010, 05:16 AM	#9
Thomas Moore Regular Crew Join Date: Oct 2009 Location: Ravenna, OH Posts: 198	Something like this YouTube - Slow Motion in Sony Vegas might help you...

January 25th, 2010, 05:31 AM	#10
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Hi Thomas Hey, thanks!! That's a nifty trick indeed!!!and coming from the home of Douglas Spotted Eagle it will be good advice!!! I'll try that on my next slo mo!!! A lot easier than getting my head around Virtual Dub or making external double frame rate files....it "cheats" a little but who cares if the end result is good??? Much appreciated..I wonder if anyone else has used this tip??? Chris