How To Reduce Strobes In Progressive? at DVinfo.net

Plamen Petrov · March 15th, 2007, 07:34 AM

Hi everyone,
I just captured from my miniDV cam (PAL 25 Interlaced), and after rendering out to DV AVI PAL Progressive, very obvious strobes are visible in the motion scenes, even if the motion is slow. So, what settings are needed so that to reduce this terrible strobed look to minimum? Any advises?

P.S.: If anybody wants, I can upload a short clip before-and-after.

Douglas Spotted Eagle · March 15th, 2007, 08:10 AM

50i at what shutter speed? Shooting is as much a part of the quotient as anything.
What are you previewing the footage with? PAL CRT monitor? Or computer screen? If you show progressive footage on a PAL CRT monitor or on most LCD television displays, it's reconverted to interlaced and you'll also potentially see the strobing.

More input, please? :-)

Plamen Petrov · March 15th, 2007, 08:29 AM

Quote:

Originally Posted by Douglas Spotted Eagle

50i at what shutter speed? Shooting is as much a part of the quotient as anything.
What are you previewing the footage with? PAL CRT monitor? Or computer screen? If you show progressive footage on a PAL CRT monitor or on most LCD television displays, it's reconverted to interlaced and you'll also potentially see the strobing.

More input, please? :-)

Shutter speed 1/50, previewing on computer monitor crt. I dont know if the moitor is the reason, but when I watch a movie on it (dvd, divx, etc.), I see no any strobes. Of course, its a question of cameras, but anyway I think my problem must have a way to be solved somehow.

Peter Jefferson · March 15th, 2007, 08:59 AM

chekc your exposure..
most of the time flicker and strobe occurs becuase your levels are exceeding safe levels..

go to view and open up your scopes.. set it up to run RGBand luminance parade and check out the levels through that.. if you notice and excessive peak on teh right hand side, youve blown ur highlgihts and they nee to come down

quick and dirty way is to run "broadcast safe" filter...

Plamen Petrov · March 15th, 2007, 10:42 AM

Quote:

Originally Posted by Peter Jefferson

chekc your exposure..
most of the time flicker and strobe occurs becuase your levels are exceeding safe levels..

go to view and open up your scopes.. set it up to run RGBand luminance parade and check out the levels through that.. if you notice and excessive peak on teh right hand side, youve blown ur highlgihts and they nee to come down

quick and dirty way is to run "broadcast safe" filter...

Hey, Peter, no, its not that. Maybe I was not clear. I mean that the strobes (or stutters) are so visible in progressive. Its not bcoz of exposure, Im sure that. Hmm, maybe I have to upload a clip very soon.

Plamen Petrov · March 23rd, 2007, 06:41 PM

When I watch some movie, I see that the strobing/stuttering lines are VERY smooth and fine (small), with very high frequency, while the same effect on my footages is with coarse and low frequency strobed lines.
Ok, look: I have a choice on my miniDV cam - to choose 1/50, 1/120, "sports", or just without any of previous options (raw, i think). So, I use 1/50, but is it the best I need for 25fps?
Also, after many variations of render and project settings I discovered that it is much better for my interlaced captured footage when I do this:
1.Changing the field order on the footage properties to progressive.
2.Project properties: progressive, deinterlaced method: none.
3 Rendering out to progressive.

Another question: on the footage properties -> media I see an option "use custom timecode". What does this do and why should I need it eventually? What is the reason to change the timecode?

March 15th, 2007, 07:34 AM	#1
Plamen Petrov Regular Crew Join Date: Feb 2005 Location: Sofia Bulgaria Posts: 147	How To Reduce Strobes In Progressive? Hi everyone, I just captured from my miniDV cam (PAL 25 Interlaced), and after rendering out to DV AVI PAL Progressive, very obvious strobes are visible in the motion scenes, even if the motion is slow. So, what settings are needed so that to reduce this terrible strobed look to minimum? Any advises? P.S.: If anybody wants, I can upload a short clip before-and-after.

March 15th, 2007, 08:10 AM	#2
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	50i at what shutter speed? Shooting is as much a part of the quotient as anything. What are you previewing the footage with? PAL CRT monitor? Or computer screen? If you show progressive footage on a PAL CRT monitor or on most LCD television displays, it's reconverted to interlaced and you'll also potentially see the strobing. More input, please? :-) __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

March 15th, 2007, 08:59 AM	#4
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	chekc your exposure.. most of the time flicker and strobe occurs becuase your levels are exceeding safe levels.. go to view and open up your scopes.. set it up to run RGBand luminance parade and check out the levels through that.. if you notice and excessive peak on teh right hand side, youve blown ur highlgihts and they nee to come down quick and dirty way is to run "broadcast safe" filter...

March 23rd, 2007, 06:41 PM	#6
Plamen Petrov Regular Crew Join Date: Feb 2005 Location: Sofia Bulgaria Posts: 147	When I watch some movie, I see that the strobing/stuttering lines are VERY smooth and fine (small), with very high frequency, while the same effect on my footages is with coarse and low frequency strobed lines. Ok, look: I have a choice on my miniDV cam - to choose 1/50, 1/120, "sports", or just without any of previous options (raw, i think). So, I use 1/50, but is it the best I need for 25fps? Also, after many variations of render and project settings I discovered that it is much better for my interlaced captured footage when I do this: 1.Changing the field order on the footage properties to progressive. 2.Project properties: progressive, deinterlaced method: none. 3 Rendering out to progressive. Another question: on the footage properties -> media I see an option "use custom timecode". What does this do and why should I need it eventually? What is the reason to change the timecode?