XL2 artifacts in 16:9 mode
 

I am using an XL2 in 16:9 mode, 24p, 3:2:2:3, I am getting an artifact on the leftmost side of each frame. The first column of pixels is darker than the rest, the next column of pixels is lighter than the rest and the next three are darker in varying degrees. This causes a faint but distinct line down the left of each frame.

Here are links to frame captures of the problem:

http://192.35.232.110/blowup.jpg - a blowup of the artifact.
http://192.35.232.110/lineonimage.jpg - capture frame.
http://192.35.232.110/lineonimageE.jpg - captured frame with arrows.

Any information or help would be appreciated.

- JR

Jese, I'm not sure if this is due to the image processing of the camera itself or the lens. What lens are you using?

I am using the standard 20X that came with the camera. I have also recorded directly to hard disk, using firewire, and I get the same artifact, so it's not the tape.

Thanks,

- JR

This is considered "normal" by Canon. I went through a big deal with Canon service about this and this was ultimately what they said. They declined to repair it under warranty. They suggested if it bothered me to crop the final output! I think their thinking is that it's outside of action safe and therefore not an issue. It's possible it doesn't appear in all cameras. It is most emphatically not about capture, or the lens, or pulldown, or frame rate (I shoot 30p and I get it with both the 20x and the 3X and even with EOS lenses; I tried every combination under the sun). Like yours, mine is exactly 5 pixels wide in the very same spot. It also doesn't appear in 4:3. Once you know to look for it, you can see this in lots of 16:9 XL2 footage. It's very annoying and clouds an otherwise very satisfying consumer experience.

But one question that nagged me and that I wasn't able to eliminate: Are you using Final Cut Pro for capture?

I wouldn't worry about it.
I have an XL2, and capture with Sony Vegas... and it has been on everything that I have shot since day one, but I only actualy noticed it recently.

Interesting. I don't have this problem. I'd be intersted in knowing whether this was a hiccup in a batch of sequentially produced cameras or an ongoing, sporadic deal. There was an unheralded change to the XL2 mid -stride that involved removal of the film grain switch. The crazy firewire connect/disconnect blown fuse deal seemed to disappear with this later produced version as well. I wonder if this ties into it at all? I have the non-film grain button version and have none of the above mentioned problems.

Hey, Eric --Mine is a post 'film-grain' model as well. Interesting to note that I have also seen the aberration on footage from PAL XL2's.

Maybe we can start doing a bit o' detective work here. Anyone else with the later "version" XL2 have this problem?

Mine is a post film grain PAL version, and, yes, the abberation is clearly visible.

If you look, most dvd releases of major holywood films have similar markings along the side.

I did not want to say this… but I think it looks sort of ‘filmic’, actually. :)

Mine's an NTSC version. Sounds like 2 PAL cameras with the problem. I'm just curious as to what specifically causes this abberation (if I can use that term).

I have captured video with Vegas 6, Microsoft video capture, and via firewire, directly to disk. All have this problem.

I have also noticed a similar artifact whenever there is a major change in color, for instance, along the border of a piece of paper, laying on a desk. I have accepted this as relating to an abrupt change in contrast. The 5 lines along the edge may be caused by a similar situation, an abrupt change in contrast or the start of a change in contrast.

This could be the result of an anti-aliasing algorithm or just what happens when there is an abrupt change in contrast.

My camera is an NTSC version.

Mine is only a few months new. I can't say that I've see the "dark line" off pixels either on my camera or computer monitor when looking at the footage.

The dark pixels are easy to miss, especially on a busy screen. Look at shots where there is a blank wall or other single colored surface that covers the left side of the frame. The effect if faint.

Normal ?
 

Brian, your quote, "This is considered "normal" by Canon," seems to be typical from some companies. They find a problem in their product and it becomes a "characteristic" of the product.

I find it hard to believe that after putting a good lens on a video capture system, they would accept this as "normal". However, I guess it depends on the cost to repair something that they overlooked in QC.

I Fed-X'ed my system to Canon yesterday. The support engineer said they had never seen this before. I can only hope they can offer a solution.

Hi Jesse. I can only repeat what Canon service told me. I sent my camera to them twice. Eventually, after numerous phone calls trying to get them to admit that they even saw the problem (it seemed pretty self-evident to me), the tech informed that the camera was within "spec" and the lines on the left hand side were considered "normal." My warranty has since run out and I will probably take a severe beating when I go to sell the camera because I'll have to disclose the "normality" to the buyer; I suppose I'll be lucky to even FIND a buyer. Good luck. I'll be interested in knowing what they do for you.

Jesse, I guess that Canon (and other manufacturers) could argue, that it is a video camera and that, normally, the artifacts are not visible because they are outside the safe area. Some cameras even show a 5 to 10 pixel black stripe on either side of the picture (my old camera did that).

It's a bit like 35 mm film: you buy a roll of film with 36 exposures. If you manage to squeeze 37 exposures on one roll and the lab cuts frame 37 in two, they won't be liable for the damage (at least it is like that over here in Germany).

Black stripe
 

I guess I could always place my own black stripe on the left side in the editing process but if the pixels were not meant to be a part of the frame, I don't think they should have included them in the frame.

Someone asked earlier if there was a break point where this artifact was introduced or went away during production. It might be good information for future reference.

Don´t want to highjack this threat, but were there any issues with the early XL2s?
Why is there a version with a filmgrain button and why was it removed later on?
We encountered some "noise" issues with our XL2 when we tried greenscreening lately, there was moskito noise all over the place.
We were testing the chromaflex system and even if DV isn´t the best for keying it should have looked better...
We even set gain to -3, but it was still there (we had 2 300watts softlight neons for the key and bounced 2 800w Arris for overall luminosity).
We have a PAL "filmgrain" version, BTW...

Christian, I have 2 XL2 (PAL), one old with the filmgrain and one newer without. I have done some greenscreening with both cameras without any noise issues, as far as you can expect from the DV-system.

My trick is to light the greenscreen as evenly as possible (I'm using almost the same amount of lights as you are). Then without any talent in front I adjust the XL2 with zebra on to find that the screen is evenly illuminated. I adjust the aperture to fill the entire viewfinder with the zebra-pattern and then adjust the aparture so the zebra-pattern disappear, it should disappear in two aperture-steps or so. If not adjust the light again.
Then place the talent i front, check that no shadow from the talent hits the screen. Light the talent carefully and the check for the zebra-pattern and any shadows on the screen again.

I also found the the quality of the keying in the NLE have a major effect on your finished result. Some third party programs like Ultra from Serious Magic will also help you to get a good result even with an unevenly illuminated screen.

- Per Johan

Hey Per,
as stated we´re using the chromaflex system for greenscreen work, it is a reflective material iluminated on camera axis by a green LED lightring.
This results in an almost evenly lit surface.
The matte itself produced with keylight in AE is ok, altough ultra2 or DVmatte will probably perform better.
We just noticed that our footage was very grainy, this isn´t normaly an issue when doing standart filming with the XL.
We were also using Canons PC-Recorder (I started another threaqt on this...).
Since I wasn´t aware, that there are to versions of the XL2, I thought maybe this grain button caused the noise due to some bug or sth...
Maybe you could share your settings with me?
We´re trying to shoot for maximum resolution always, "filmlook" if desired, is achieved in post.
Thanks,

Chris

I am amazed that you guys think this is a non issue, especially on a camera of this price and class. The old XL1's had black lines on the sides of the footage and I thought that was bad, but people put up with it. Now, we're many years on from that camera, and there are still issues. On top of that it's not with all cameras, so it's not a design flaw, it's a defect IMO. I would go to whatever department deals with consumer affairs in your country and take action. If you're making a film for projection (not TV) then you don't the lines and you shouldn't have to "crop the final output" - what a joke.

Aaron

National Geographic
 

I watched some of a National Geographic show on crocodiles. I was amazed that almost every frame had similar "artifacts" on the left hand side. Even some of the commercials.

This is the first time I've ever noticed this. I usually can't see this on my TV because it cuts off pixels on the borders. I was watching this on my PC which shows the entire frame.

Currently, much of the video I shoot is for distribution on PC's. As such, there is no "safe zone". The entire frame shows up. I may have to live with the artifacts, but I don't like it. It just seems a little less than it should be.

- Jesse

Same Here
 

Hi, I too have the problem with the line down the L/H side of the frame in 16:9 mode using a PAL sytem XL2 (purchased new in March this year) in either 25p or 50i mode. Slightly annoying, though not as bad as an old Panasonic MS4 (S-VHS, single chip) I have that gives an area with no colour about 20/30 pixels wide on the right of the frame. In truth though, never a problem withTV's only apparent on PC's. More annoying though is that following your advice re capture I bought a Canon MV790 for £180.00 to play back tapes for capturing only to save wear and tear on the XL2. This little camera has both 4:3 and a 16:9 mode that (per the manual) 'uses the full width of the CCD' sounding similar to way the XL2 produces 16:9 by using more pixels. Guess what, the cheapo camera does not display any artefacts at all! Explain that one! Bear in mind though, I paid around £1,600.00 for the MS4 in the early 1990's and that was a not incosiderable sum then. I have paid £2,800.00 for the XL2 around 13 years later. I know it's still a lot of money but it's far better value than was the MS4 and is a far better camera. I also think that as we are getting a very good camera for the price then something like this is a thing that I at least,can put up with it. Had I paid out broadcast type money for a real broadcast quality camera I would be extremely disappointed/annoyed, but I haven't. Like anything in this world I suppose to a degree, you get what you pay for.

I could not see it until I looked at the blow up portion. I mean do you think someone watching footage on their PC is going to notice this?

If it is only 5 pixels and your crop 5 pixels from the side and the top to keep the same ratio, the resolution is not going to change enough to be noticable, right?

Mine has been fixed?
 

I sent mine into Canon for warranty repair.

They said they found a tiny piece of tape stuck in the transport and that MIGHT be the problem.

The camera sill exhibits the artifact but much more faintly, in some cases it doesn't show at all.

Funny thing is, I tested the camera, before I sent it in for warranty, capturing directly to disk, not using the tape transport. It had the artifact on the the files captured directly to disk.

It makes me think that they may know what the problems is, can adjust the camera to minimize the problem but don't admit it and then tell customers the problem was something in the transport to draw attention away from the real problem.

I have several theories on why they do this but probably shouldn't go into it here.

It's not that I don't like the camera, I do. In fact, I love what I can do with it. But the logic of what I've been told doesn't jive with what I know.

- Jesse

It's probably not as big a deal as I've made of it.
 

Neil,

My background has been more with still than video. I also do a lot of work in Photoshop and other graphics packages. Typically, if a pixel is out of place on a 2000 X 1500 image, I know it and I can't stand it until it's fixed. If it were a 5 pixel wide problem in the same image, it would be unacceptable to me (and probably my clients).

It seems, in video, that this artifact is within acceptable parameters. Something I will probably grow to appreciate in the future.

- Jesse

I got my xl2 2 months ago and I have that artifact at left thin vertical purple line in 25p 16x9, but I m accustomed to see such artifacts in some commercial programmes. also I have faced same line with sony vx200 4:3 pictur so I try not to see it. and I now feel more relaxed that everybody has it :)

alkim.