strange blocky artifacts at DVinfo.net

Mike Andrade · February 2nd, 2007, 12:41 AM

I shot this show last night and when I captured the footage to fcp I noticed some strange lines and blocky artifacts on the talent. When I was looking at the crt everything looked fine and when I watched it on my tv it looked fine as well. Its when i captured it in fCP that I noticed this mess.

I shot at 24p standard with a shutter speed of 1/48th. The venue was pretty dark so I boosted the gain to +3, the coring +3, dropped the sharpness -2, and boosted the color gain a couple notches with blacks pressed. I have had this issue before with reds but its usually isolated to that color. This can be seen on the face and body of the singer. The only thing that seems to aleviate it is a color smoothing filter. Can anyone tell me what would cause this and why I only see it in my NLE? Any help would be greatly appreciated. Thanks

Ash Greyson · February 2nd, 2007, 03:30 AM

Did you shoot it with 2:3:3:2 or 2:3 pulldown? Ar you editing in 24P? Remember, that computer monitors are not interlaced. You should really get yourself and external monitor, many times your computer screen will show problems that are not really there.

ash =o)

Mike Andrade · February 2nd, 2007, 01:41 PM

Ash,

It was the regular 2:3 and editing in 29.97. After messing with this till the wee hours of the morning I noticed when I drop the saturation down to almost a flat image, the artifacts go away. Its almost like the blue and green stage Led's are causing this but only visible on the computer screen. I used a variation of your saturated crushed black setting but adjusted it for low light. Do you think the saturation of the blues and greens could have contributed? I shot a test of the band that played before at sound check under the white house lights and it looked perfect.

I also thought it was an interlacing issue and tried a deinterlace filter which did no good.I've dealt with interlacing before but I've never had it on the suject I'm shooting, usually on horizontal lines, patterns, etc...Those grabs werent the greatest and its alot more noticeable when the video is playing. The closeups I shot of the subjects hands fretting the guitar look like "Thing" the comic character, blocky and pixelated.

Ash Greyson · February 2nd, 2007, 07:07 PM

Is this for a DVD? If so, I would use CinemaTools to reverse telecine the footage and edit in a 24P timeline.

Blue is the sharpest channel in DV land, that sharpness can cause noise artifacts, you made the correct call on the coring and sharpness but you might have wanted to turn down just the blue a little. Generally in DV world, any color bath but green will cause issues...

ash =o)

Mike Andrade · February 2nd, 2007, 07:30 PM

Yeah the lighting was tough because they had 2 big dense lcd's and a few track spots. I worked with the tech to get the brightest light we could and it happened to be that dense blue and green scheme. I just realized that the setting I used had the blue boosted which I overlooked. I was so worried about the low light issue that I didnt factor that in being a problem.

Its actually for the web which now sucks because It looks fine on dvd. I've got to have this to the client by Monday and I have been at it all day trying to get it to look ok. He is actually cutting it and wants a copy straight to tape. I have shot several shows lately that came out pristine and now this client is gonna think I don't know the settings on my own camera. Oh well another hard lesson in DV cinematography.

Ash Greyson · February 3rd, 2007, 12:04 AM

Put it in an uncompressed timeline, then render a chroma blur...that will get rid of most the artifacts.

ash =o)

Mike Andrade · February 7th, 2007, 02:59 AM

Ash,

I tried the h. chroma blur in FCP but it didn't make a difference in the uncompressed timeline. Is this the right one to use or is there a better one you suggest? Thanks

February 2nd, 2007, 12:41 AM	#1
Mike Andrade Regular Crew Join Date: Jul 2006 Location: Austin, Tx Posts: 136	strange blocky artifacts I shot this show last night and when I captured the footage to fcp I noticed some strange lines and blocky artifacts on the talent. When I was looking at the crt everything looked fine and when I watched it on my tv it looked fine as well. Its when i captured it in fCP that I noticed this mess. I shot at 24p standard with a shutter speed of 1/48th. The venue was pretty dark so I boosted the gain to +3, the coring +3, dropped the sharpness -2, and boosted the color gain a couple notches with blacks pressed. I have had this issue before with reds but its usually isolated to that color. This can be seen on the face and body of the singer. The only thing that seems to aleviate it is a color smoothing filter. Can anyone tell me what would cause this and why I only see it in my NLE? Any help would be greatly appreciated. Thanks Attached Thumbnails __________________ Mike A

February 2nd, 2007, 01:41 PM	#3
Mike Andrade Regular Crew Join Date: Jul 2006 Location: Austin, Tx Posts: 136	Ash, It was the regular 2:3 and editing in 29.97. After messing with this till the wee hours of the morning I noticed when I drop the saturation down to almost a flat image, the artifacts go away. Its almost like the blue and green stage Led's are causing this but only visible on the computer screen. I used a variation of your saturated crushed black setting but adjusted it for low light. Do you think the saturation of the blues and greens could have contributed? I shot a test of the band that played before at sound check under the white house lights and it looked perfect. I also thought it was an interlacing issue and tried a deinterlace filter which did no good.I've dealt with interlacing before but I've never had it on the suject I'm shooting, usually on horizontal lines, patterns, etc...Those grabs werent the greatest and its alot more noticeable when the video is playing. The closeups I shot of the subjects hands fretting the guitar look like "Thing" the comic character, blocky and pixelated. __________________ Mike A

February 2nd, 2007, 07:30 PM	#5
Mike Andrade Regular Crew Join Date: Jul 2006 Location: Austin, Tx Posts: 136	Yeah the lighting was tough because they had 2 big dense lcd's and a few track spots. I worked with the tech to get the brightest light we could and it happened to be that dense blue and green scheme. I just realized that the setting I used had the blue boosted which I overlooked. I was so worried about the low light issue that I didnt factor that in being a problem. Its actually for the web which now sucks because It looks fine on dvd. I've got to have this to the client by Monday and I have been at it all day trying to get it to look ok. He is actually cutting it and wants a copy straight to tape. I have shot several shows lately that came out pristine and now this client is gonna think I don't know the settings on my own camera. Oh well another hard lesson in DV cinematography. __________________ Mike A

February 7th, 2007, 02:59 AM	#7
Mike Andrade Regular Crew Join Date: Jul 2006 Location: Austin, Tx Posts: 136	Ash, I tried the h. chroma blur in FCP but it didn't make a difference in the uncompressed timeline. Is this the right one to use or is there a better one you suggest? Thanks __________________ Mike A

February 2nd, 2007, 03:30 AM	#2
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	Did you shoot it with 2:3:3:2 or 2:3 pulldown? Ar you editing in 24P? Remember, that computer monitors are not interlaced. You should really get yourself and external monitor, many times your computer screen will show problems that are not really there. ash =o)

February 2nd, 2007, 07:07 PM	#4
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	Is this for a DVD? If so, I would use CinemaTools to reverse telecine the footage and edit in a 24P timeline. Blue is the sharpest channel in DV land, that sharpness can cause noise artifacts, you made the correct call on the coring and sharpness but you might have wanted to turn down just the blue a little. Generally in DV world, any color bath but green will cause issues... ash =o)

February 3rd, 2007, 12:04 AM	#6
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	Put it in an uncompressed timeline, then render a chroma blur...that will get rid of most the artifacts. ash =o)