Vertical Columns Pixel Problem...HELP!

R

ryankee

New member
Hey guys,
Great forum. I just recently bought a brand new dvx100b and began working with a partner on a project. However, when we began to look at some of the footage together we noticed these very faint vertical pixel problems. It almost looked like columns. It was very faint, but would show up better when we put a lot of contrast on the shot.
I've included some screen shots, but you can see it even better in live footage cause the camera can move around, but the line stays...thats how we saw it in the first place. Also, there is a slight tone difference between one column and the other.
If any one has any feedback, I would love to get it. I'm in Europe right now doing some shooting, and I need to know if this is something I should get back to the states and send off to panasonic or what.
The only tape I have used thus far is the Panasonic Master Series tape that came with the camera. I thought that perhaps, by some wierd circumstance the heads could be dirty so I put a cleaning tape through it, but the problem remains.
The problem is in both NTSC and 24p.
In the screen shot of the guy looking down, look at his right collar of his shirt, it is most noticable there. Its in the other screen shots as well, a little hard to see. Its much more easily idetifiable in moving video, because the columns stay there, even if the subject moves. On a laptop screen they are roughly 1.2 cm in width.
Maybe its something really simple that I don't understand. I am just getting into more pro video stuff, so I would appreciate any wisdom from you guys. Has anyone ever seen anything like this? Do I have damaged heads from the factory? The artifacts were hard to see at first, but now they are so present in my eye, I find it totally unacceptable. Thanks.

Ryan

http://i21.photobucket.com/albums/b260/ryan_kee/Running-origin.jpg
http://i21.photobucket.com/albums/b260/ryan_kee/dddd.jpg
http://i21.photobucket.com/albums/b260/ryan_kee/24p.jpg
 
To be perfectly honest, I can't see anything in particular.
Can you post a short clip?
 
I didn't notice anything out of the ordinary, but I am guessing that you're talking about 4:1:1 color sampling and the blockiness that comes about when using it? The pic of the jogger shows that all over it, so I am guessing that that's what it is.

Here's the key determining factor: do you only see it on the footage in a computer? Or do you also see it when displayed on an interlaced television?

Also, if you're shooting NTSC in Europe and converting to PAL DV, you'll exaggerate the issue.
 
Ryan,

Which white balance setting were you using? Auto, manual, or a preset (3.2k/5.6k)?

I have seen a vertical line problem in manual white balance on the DVX100 and even on Panasonic consumer cameras, like the GS400. Here are some examples from the GS400:

http://www.matterofchance.com/gs400/lines01.png (original)
http://www.matterofchance.com/gs400/lines01a.png (enhanced to highlight the lines)
http://www.matterofchance.com/gs400/lines02.png (original)
http://www.matterofchance.com/gs400/lines02a.png (enhanced to highlight the lines)

As I said, I have seen this exact effect on the DVX100B as well. After getting dinged by this a couple times, I use the presets exclusively now, as they don't have this issue.

Josh
 
Thanks Josh and Barry. I appreciate the quick reply's. Barry, as you said, its only on the footage when I look at it on a computer screen. When I am looking at it on my attached tv monitor I see no artifacts.
Joshua, I will try and get some footage with the auto white balance enabled. I'm pretty sure that the previous footage was with manual white balance. THANKS a bunch for the screen shots...they helped a lot. Me and my partner looked at the pictures and yelled with excitement that finally we had found somethink that looks like our problem. Our footage is by no means as pronouced as yours. The problem is very minute, and to the average eye not really noticable to the average viewer...but to someone sitting infront of a computer all day editting, you start seeing it.
So, the question is....are these just issues with the dvx100b that are there and I should learn to live with them? As I said, I just got my dvx100b so I am definitly still learning all the ins and outs of it(By the way Barry, I got your book and its being shipped to my house).
I am doing some shooting in Europe, but not converting to PAL dv...just getting some shots for some promo work that I am doing over here. Everything will be shot and edited in NTSC.
So, I will try some of these things out and see what happens. What I am hearing is that (praise God) I don't need to send my cam to Panasonic...I just need to read and learn more how to use my cam.
Thanks a million,
Ryan

P.S. Barry, I see you live in North Carolina! I live in Greensboro, where do you live?
 
Ryan,

See if you can post a full 720x480 screen grab somewhat uncompressed, and I'll take it into Photoshop and see if it's got the same problem. If it is this problem, it's a pretty pervasive Panasonic issue, proline and consumer cams. It's only when using a manual white balance and shows up mostly when shots are a tad underexposed or in shadow areas.

Josh
 
So, I think what I am dealing with is looking at the footage on a computer. I don't notice the problem on my break out monitor. However, my partner who was looking at capture footage on his laptop saw it, and brought it to my attention. His point is that he doesn't see this verticle blocking/column when he looks at footage of his sony trv900. Its true, his SD sony trv900 doesn't put out footage that I can see these very faint column blocking, but the dvx100b...a way more expensive camera...does have very very some slight columns.
So, here is my question. I do about half work for dvd, and about half for web. Since I have so many viewers watching my footage on computers, should I have bought the hvx instead. Or, is there any tricks for exporting footage from the dvx100b that is well viewable on a computer? I understand that SD footage is meant to be watched on tv, but I am just asking. Any wisdom out there.

Here is another screen shot:
http://i21.photobucket.com/albums/b260/ryan_kee/Seongahtest.jpg
 
To fix (or at least minimize the problem), try applying a chroma blur filter to the horizontal pixels in your NLE.
 
Hey guys, one more thing. Here are some much more clear screen shots. They are the same as the first shots I put up, but when I uploaded them to photobucket I forgot that I had the 800x600 preset. So, I uploaded these pictures.
You will see that the artifacts are much easier to see. Have a look at these pictures, and the pic from the last post and let me know what you guys think.
Thanks

http://i21.photobucket.com/albums/b260/ryan_kee/Running-effect.jpg
http://i21.photobucket.com/albums/b260/ryan_kee/24p-1.jpg
 
Ryan,

It looks like normal result of chroma subsampling (4:1:1), but it actually looks much blockier than that. Do you have chroma turned all the way up or something?

Josh
 
guys, i'm having a problem as well. i don't know what's up, but it's happening on both of my dvx 100b's and i don't know if it's normal. i wasn't editing the footage. at first we thought it was a faulty tape, but i captured this footage on a firestore while shooting. i know that reds and blues are pretty blocky, but this guy's face in the first shot is messed up and it happened on three occasions, with three different dvx100b's. there was very little detail in his eyes and it looked like there was a ghost image on a lot of the image, the footage kept jumping intermittently as well. they were watching the footage full screen on an lcd monitor. on a crt, it's not as bad.

take a look at some recent footage i shot:

2mxe3c1.jpg


f36pvl.jpg



this one was a different shoot, but i noticed it being pixellated around the edges on her body.

343i6pz.jpg


i'm getting to the point where i'm getting scared to use my cameras anymore. one has 93 hours on it, the other has 193. help!!!!

now that i look at it, it's hard to notice in these photos. it's way more prevalent on a computer monitor. would this kind of thing show up on a plasma screen or a large lcd television?
 
Are you just talking about the interlacing? Shoot in a progressive format and you won't see interlacing.

If the interlacing is what you're concerned about, it's completely normal.
 
thanks for the reply. i shot the footage in 60i and when you capture the footage or play it on an lcd monitor, it looks like there's a ghost image (when i say ghost image, i mean it looks like there is a faint second edge to the top of certain area, almost out of phase?). like i had mentioned before, there i had no explanation for it because it had never happened before and we had shot there 6 times previously, and this was the first time the issue popped up. the same issue happened two more times, but i'm thinking it's possible the camera and footage may have been affected by the large magnetic amps that were sitting all around us. the footage plays back normal on a crt tv, but computer monitors look like crap.
 
You are shooting interlaced, so you will be able to see the interlacing lines when things move. You won't see it on a TV, you will see it on a progressive LCD display, exactly as you describe. This is normal. Shoot progressive mode if you don't want interlacing.

Also, you're color blockiness looks absolutely normal.
 
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