No more moire! at DVinfo.net

Patrick Janka · March 25th, 2011, 11:20 PM

I did a test shot of a friend in front of my green screen shot at 1080p 24p. Something I found very odd is that the smaller the dimensions of my video player the worse the moire gets from his striped shirt. As I increase the dimensions the moire starts to disappear. However, after uploading it to YouTube I found at the smallest dimensions there was very little moire, and at full screen there was little moire, but at the midpoint (expand button) I get some pretty bad moire. What's going on here? I thought the GH2 had solved the moire issue. Here's the clip: YouTube - Tweople Test

Brian Luce · March 26th, 2011, 02:19 AM

I don't think anyone said GH2 solves the Moire issue completely. Moire can appear in very expensive cams. I think what was said was that for Canon DSLR shooters, the GH2 greatly reduces the amount of moire and artifacting. It can still crop up, but it's now manageable.

Jeff Harper · March 26th, 2011, 07:03 AM

No CMOS based camera can "solve" the moire issue, it is a problem that comes with all CMOS sensors.

You are seeing moire because you are taping a subject with pinstripes on. Experienced videographers know this is normal. It is like wearing certain colors for television, they just don't work, it is not recommended.

The camera is fine. The solution? Have your subject wear appropriate clothing.

Les Wilson · March 26th, 2011, 07:19 AM

Pinstripes and tight patterns are the worst case situation for any camera. It's been that way ummm forever. From Wikipedia: Moiré pattern - Wikipedia, the free encyclopedia

Moire patterns occur as the result of scaling down images. Some things scale without effect while others (like tight patterns and pin stripes) introduce the effect.

The GH2 is scaling the image from it's sensor resolution to 1920x1080 using all kinds of technology and ummmm magic. It's supposedly one of the better bits of magic. Anyway......

Is there moire in the recorded HD image? If you scale an image in post production or playback and get moire, it's kinda hard to blame the camera.

Jeff Harper · March 26th, 2011, 07:48 AM

Oh, right Les, I forgot that aspect, you are correct of course, his talk of different issues happening in relation to the media player exonerates the camera.

Patrick, as noted you should be discussing what you seen in the raw video when discussing moire.

We've had this discussion I think Patrick. Artifacts and such that happen after conversion have nothing to do with the camera but with improper conversion of footage. That issue is something completely different.

Patrick Janka · March 26th, 2011, 09:06 AM

Yes, it's in the raw file as well. I don't generally have talent wear striped patterns, but he came over wearing it so I figured why not leave it on and see what happens. I know all about rescaling and whatnot. I was mainly testing audio syncing using PluralEyes to send to a client who was skeptical of using dual system sound. I used a Sony UWP-V1 wireless lav. I'm a bit bummed that my Jag35 monitor's colors were quite different from the flip out lcd of the GH2. I'll have to mess with the settings, but there aren't many adjustment options. I also wish the monitor was HD for easier focus pull, but it just wasn't in my budget so I'll have to deal.

Les Wilson · March 26th, 2011, 11:26 AM

BTW, you pulled a nice key. I would not have noticed the moire.

Patrick Janka · March 26th, 2011, 12:04 PM

Thanks, Les. I use the ultra keyer in Premiere. The screen was a bit wrinkled and unevenly lit, but I only took one color sample and adjusted a few settings. The lights were all fluorescent. His arms got cut off a little at the end because I'd also used a 4 point garbage matte, but didn't adjust it to the full length of his arms when he spread them out. The background was just some pic I quickly grabbed from Google.

Jeff Harper · March 26th, 2011, 01:35 PM

I agree with Les, the footage looked darn good, you really have nothing to be bummed about. That moire or whatever it is was so normal and minimal, forget about it.

Brian Luce · March 26th, 2011, 02:30 PM

I couldnt even see the moire. I looked too.

March 25th, 2011, 11:20 PM	#1
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	No more moire! I did a test shot of a friend in front of my green screen shot at 1080p 24p. Something I found very odd is that the smaller the dimensions of my video player the worse the moire gets from his striped shirt. As I increase the dimensions the moire starts to disappear. However, after uploading it to YouTube I found at the smallest dimensions there was very little moire, and at full screen there was little moire, but at the midpoint (expand button) I get some pretty bad moire. What's going on here? I thought the GH2 had solved the moire issue. Here's the clip: YouTube - Tweople Test

March 26th, 2011, 02:19 AM	#2
Brian Luce Inner Circle Join Date: Jan 2006 Posts: 2,290	Re: No more moire! I don't think anyone said GH2 solves the Moire issue completely. Moire can appear in very expensive cams. I think what was said was that for Canon DSLR shooters, the GH2 greatly reduces the amount of moire and artifacting. It can still crop up, but it's now manageable.

March 26th, 2011, 07:03 AM	#3
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: No more moire! No CMOS based camera can "solve" the moire issue, it is a problem that comes with all CMOS sensors. You are seeing moire because you are taping a subject with pinstripes on. Experienced videographers know this is normal. It is like wearing certain colors for television, they just don't work, it is not recommended. The camera is fine. The solution? Have your subject wear appropriate clothing. __________________ "The horror of what I saw on the timeline cannot be described."

March 26th, 2011, 07:19 AM	#4
Les Wilson Inner Circle Join Date: Jan 2004 Location: Boca Raton, FL Posts: 3,014	Re: No more moire! Pinstripes and tight patterns are the worst case situation for any camera. It's been that way ummm forever. From Wikipedia: Moiré pattern - Wikipedia, the free encyclopedia Moire patterns occur as the result of scaling down images. Some things scale without effect while others (like tight patterns and pin stripes) introduce the effect. The GH2 is scaling the image from it's sensor resolution to 1920x1080 using all kinds of technology and ummmm magic. It's supposedly one of the better bits of magic. Anyway...... Is there moire in the recorded HD image? If you scale an image in post production or playback and get moire, it's kinda hard to blame the camera.

March 26th, 2011, 07:48 AM	#5
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: No more moire! Oh, right Les, I forgot that aspect, you are correct of course, his talk of different issues happening in relation to the media player exonerates the camera. Patrick, as noted you should be discussing what you seen in the raw video when discussing moire. We've had this discussion I think Patrick. Artifacts and such that happen after conversion have nothing to do with the camera but with improper conversion of footage. That issue is something completely different. __________________ "The horror of what I saw on the timeline cannot be described." Last edited by Jeff Harper; March 26th, 2011 at 08:53 AM.

March 26th, 2011, 09:06 AM	#6
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Re: No more moire! Yes, it's in the raw file as well. I don't generally have talent wear striped patterns, but he came over wearing it so I figured why not leave it on and see what happens. I know all about rescaling and whatnot. I was mainly testing audio syncing using PluralEyes to send to a client who was skeptical of using dual system sound. I used a Sony UWP-V1 wireless lav. I'm a bit bummed that my Jag35 monitor's colors were quite different from the flip out lcd of the GH2. I'll have to mess with the settings, but there aren't many adjustment options. I also wish the monitor was HD for easier focus pull, but it just wasn't in my budget so I'll have to deal.

March 26th, 2011, 11:26 AM	#7
Les Wilson Inner Circle Join Date: Jan 2004 Location: Boca Raton, FL Posts: 3,014	Re: No more moire! BTW, you pulled a nice key. I would not have noticed the moire.

March 26th, 2011, 12:04 PM	#8
Patrick Janka Major Player Join Date: Jan 2010 Location: Orlando, FL Posts: 623	Re: No more moire! Thanks, Les. I use the ultra keyer in Premiere. The screen was a bit wrinkled and unevenly lit, but I only took one color sample and adjusted a few settings. The lights were all fluorescent. His arms got cut off a little at the end because I'd also used a 4 point garbage matte, but didn't adjust it to the full length of his arms when he spread them out. The background was just some pic I quickly grabbed from Google.

March 26th, 2011, 01:35 PM	#9
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: No more moire! I agree with Les, the footage looked darn good, you really have nothing to be bummed about. That moire or whatever it is was so normal and minimal, forget about it. __________________ "The horror of what I saw on the timeline cannot be described."

March 26th, 2011, 02:30 PM	#10
Brian Luce Inner Circle Join Date: Jan 2006 Posts: 2,290	Re: No more moire! I couldnt even see the moire. I looked too.