Artifacts in video at DVinfo.net

Dan McGuckin · July 30th, 2012, 09:39 AM

So lately I've been noticing a shimmering artifact of sorts in the bottom left of my videos.
It almost looks like the shimmering that a heat mirage on the road produces. It's not horribly noticable, but I do notice it.
This happens with or without the wide angle lens on there, and it is on the raw footage, not just rendered footage.
Attached is a link to a video the password is "sample"

You will notice it in the bottom left corner of the screen. It does show in the mesh of the chair, but it's not the chair that's causing it, as you will also notice it in the bedroom scene as well.
Any ideas?

Colin Rowe · July 30th, 2012, 03:58 PM

looks like classic moire.

Chris Harding · July 30th, 2012, 06:20 PM

Hi Dan

Colin is correct!! Any object with a square pattern or grid will look like that and shimmer. You might even see it in professional productions!! DSLR's tend to suffer from it too!!

What Panasonic camera are you using here?

The really simple way to fix something like this is to change the blanket!!

Chris

Dan McGuckin · July 30th, 2012, 08:05 PM

Hmm.. I guess I shouldn't have put the chair scene in there since that just made it that much more noticable, It seems to be in any shot that has movement in it, and always ONLY in that bottom left corner. ( which the chair was in )

Chris Harding · July 30th, 2012, 10:23 PM

Hi Dan

Moire will occur mainly with things like checked clothing and anything that often has a regular pattern ..I had bad moire on a huge brick wall quite some time ago.

Technical specs of the shoot?? What camera and what settings and format?? It used to be a massive issue in the VHS days but it might even be a lighting issue (did you have flouros ???) Depending on your camera you can often adjust shutter to eliminate the problem..most Pro Panny cameras have Syncro Shutter.

If you can provide shoot details it might help spot the gremlin?

Chris

Dan McGuckin · July 31st, 2012, 09:36 AM

Here is a shot taken from yesterdays shoot. 30p shutter speed 60. Look at the candle on the table.
This is set on a tripod with no movement on the floor, nothing was vibrating the camera.
PW is "sample"
The lighting is florescent

Colin Rowe · July 31st, 2012, 09:56 AM

Have you got ois switched on ? If so, try switching it off when the camera is tripod mounted

Dan McGuckin · July 31st, 2012, 10:13 AM

That's what I thought too, tried both ways. No help.

Chris Harding · July 31st, 2012, 06:42 PM

Hi Dan

What camera are you shooting with??? That might provide a few clues??

Chris

July 30th, 2012, 09:39 AM	#1
Dan McGuckin Regular Crew Join Date: Jun 2011 Location: Charleston, SC Posts: 71	Artifacts in video So lately I've been noticing a shimmering artifact of sorts in the bottom left of my videos. It almost looks like the shimmering that a heat mirage on the road produces. It's not horribly noticable, but I do notice it. This happens with or without the wide angle lens on there, and it is on the raw footage, not just rendered footage. Attached is a link to a video the password is "sample" You will notice it in the bottom left corner of the screen. It does show in the mesh of the chair, but it's not the chair that's causing it, as you will also notice it in the bedroom scene as well. Any ideas? Private Video on Vimeo

July 30th, 2012, 03:58 PM	#2
Colin Rowe Major Player Join Date: Jan 2004 Location: Cornwall UK Posts: 793	Re: Artifacts in video looks like classic moire. __________________ Colin

July 30th, 2012, 06:20 PM	#3
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: Artifacts in video Hi Dan Colin is correct!! Any object with a square pattern or grid will look like that and shimmer. You might even see it in professional productions!! DSLR's tend to suffer from it too!! What Panasonic camera are you using here? The really simple way to fix something like this is to change the blanket!! Chris

July 30th, 2012, 08:05 PM	#4
Dan McGuckin Regular Crew Join Date: Jun 2011 Location: Charleston, SC Posts: 71	Re: Artifacts in video Hmm.. I guess I shouldn't have put the chair scene in there since that just made it that much more noticable, It seems to be in any shot that has movement in it, and always ONLY in that bottom left corner. ( which the chair was in )

July 30th, 2012, 10:23 PM	#5
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: Artifacts in video Hi Dan Moire will occur mainly with things like checked clothing and anything that often has a regular pattern ..I had bad moire on a huge brick wall quite some time ago. Technical specs of the shoot?? What camera and what settings and format?? It used to be a massive issue in the VHS days but it might even be a lighting issue (did you have flouros ???) Depending on your camera you can often adjust shutter to eliminate the problem..most Pro Panny cameras have Syncro Shutter. If you can provide shoot details it might help spot the gremlin? Chris

July 31st, 2012, 09:36 AM	#6
Dan McGuckin Regular Crew Join Date: Jun 2011 Location: Charleston, SC Posts: 71	Re: Artifacts in video Here is a shot taken from yesterdays shoot. 30p shutter speed 60. Look at the candle on the table. This is set on a tripod with no movement on the floor, nothing was vibrating the camera. PW is "sample" The lighting is florescent Private Video on Vimeo

July 31st, 2012, 09:56 AM	#7
Colin Rowe Major Player Join Date: Jan 2004 Location: Cornwall UK Posts: 793	Re: Artifacts in video Have you got ois switched on ? If so, try switching it off when the camera is tripod mounted __________________ Colin

July 31st, 2012, 10:13 AM	#8
Dan McGuckin Regular Crew Join Date: Jun 2011 Location: Charleston, SC Posts: 71	Re: Artifacts in video That's what I thought too, tried both ways. No help.

July 31st, 2012, 06:42 PM	#9
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: Artifacts in video Hi Dan What camera are you shooting with??? That might provide a few clues?? Chris