What were the settings on the camera? I have no idea if this could be the cause, but.... the XL2's coring function is supposed to help decrease detail thats not importantant to the image... perhaps the corings on to high for those images and it decreased the resolution and added artifacts. I don't think it should do that but its worth bringing up.

Barry or somebody else would know a lot more about this than I do, but my understanding is that the Coring adjustment controls video noise levels in areas of the image containing smooth, even surfaces -- and not in busy patterns such as a brick wall. So I don't think the Coring adjustment would be very effective here. But what do I know; I've never used a camera that had that type of adjustment.

did I see it correctly that you use a composite cable to capture uncompressed? Use YC or component if you can. 10 bit Uncompressed capturing is overkill for composite video. Composite video cables can give you a moire pattern even with the best cameras. Composite cables just don't have the bandwidth and all three channels(Y,U,and V) are smashed down to one channel. This was why YC(S-Video cables) were invented. Their main purpose was to try and get rid of moire patterns and it worked for the most part. Component is even better. Why don't you try capturing regular firewire and see how that looks on your computer. If I am mistaken about you using a composite cable then forget this post. Hope this helps however.

To Rob: Yes will look at that feature.

Yes, will try digitising in using different output although I think it will still be there.

Let me explain. The image showing the moire was deliberately taken adding fields since it was the only way to illustrate and show the moire as seen on the video monitor. The image underneath on the webpage shows what is visible on the TFT screen from FCP. No moire. The image above is showing the closest impression of the video monitor NOT what is in FCP.

Therefore, YES it will show artifacting of other kinds through getting it as a web born image but that was not what was intended to show. JUST the moire. Hence the reason why the Gull and Carousel images were posted to make sure people were aware that apart from the moire, the image quality is superb.

Sorry Barry but I we are definately going to have to agree to disagree. From an aesthetic point of view, I would not blame any DOP who would simply not stand for moire or to be limited by such regardless of the format. But that's the catch. This camera is trying to pretend to not be DV. Its pretending to be something it isn't and many are going to fall into the trap of using it thinking they can get a film without shooting on stock. Not everyone would have your knowledge or understanding but at the same time, people will judge with their own eyes. YES the moire is on the screen, YES it is ugly and NO you do not have to accept it as part of the medium when you want to create a great looking film.

Clive,

Thomas is absolutely right - I hadn't seen that you captured this image in composite. Most of the artifacts are in keeping with a composite image. This is, as you know, the lowest quality of video capture. You need to capture this into FCP as native DV digitally then export it as a still.

It is all very well saying to us that your only concern is the moire, and that's all you want us to look at, but we cannot judge the extent of the moire problem whilst we are looking at far more serious artifacts.

I am a little concerned that you are basing feedback to both the BBC and Canon based on this clearly unrepresentative method of capture.

Best regards,
John.

John

The moire was seen in the following ways:

1. In the viewfinder at acquistion

2. Playing out of the camera into a video monitor both s-vhs and composite

3. Moire was seen digitised into Media 100 both firewire and s-vhs and included drop out.

Please understand that we are professionals too and just because every fact hasn't been noted here doesn't mean they haven't been tried.

I'm going to leave this discussion now purely for the fact that until everyone sees the issue at hand with their own eyes, there's no point spending so much time trying to explain it. I was hoping that others had played with the camera and had possibly experienced the same problems we have. Clearly not yet.

As Barry has said the problem of moiré is inherent to some extent in all CCD cameras and was a problem in earlier tube cameras as well.

Part of the artistry of a DOP is to work within the bounds of the medium at hand to achieve great looking pictures. If you must have all the parameters of the “Film Look” shoot film.

When I worked at NBCTV-NY we had producers that hated video and complained about all the technical stuff they could not ignore. They hated the fact that they could not hold a piece of tape up to a light and see an image. I worked on one edit session for ‘Saturday Night Live’ that wasted 36 hours at $800.00 an hour trying to do a croma key for a skit because the producer would not admit that there was way to much green spilling onto the puppet. We were even using an Ultimatte. For another skit we had to “dirty up” footage from an L1 to make it look bad enough for the look the show wanted.

I don’t see that the XL2 is pretending to be anything. The spec sheet and the brochure say that it is a DV camera. What it does appear to be doing is pushing the limits of what can be achieved with a DV camera just a little further that any thing before it.

Clive,

"Please understand that we are professionals too and just because every fact hasn't been noted here doesn't mean they haven't been tried."

I am in no way suggesting you're not, and you might have seen this moire problem any which way, however all you've supplied us with is a composite capture still that has its own inherent problems that obscure the moire - the resolution and artifacts on this one still are so bad that it is almost impossible to judge it.

If this were truly the only image I had seen from the XL2 I would be seriously worried about its quality as, and this is no reflection on your ability, it is one of the worst quality images from a DV camera that I have seen.

I agree as well with Barry - moire is a fact of digital video life under certain conditions, but until you supply us with a still from a the native DV capture we cannot comment on how bad the problem truly is with the XL2.

Best regards,
John.

Clive,

it is also possible that some of the artifacts are due to the upsampling process.

Is it possible for you to post an original JPEG 720X576 JPEG (best depth) ?

thanks

Clive, I completely understand your frustration. However, this truely is not a problem with the camera, it is a problem with the current broadcasting standard, both PAL and NTSC. I have a NTSC DVX100a and have been deeling with this for months. In the DVX there are settings for Thin, mid, and Thick vertical detail settings. The thick is meant for broadcast standards and actually ends up reducing the image quality by about 1/3. WHen viewed on a standard definition television, however, the footage looks great. If you really want to look at it, this is not a problem with the camera at all, in that it captures more information than can actually be displayed on a televison, resulting in the moire patterning. I always shoot in thin mode, even if I know that it is only going to be shown on a television. Why, because it gives me more resolution to work with. THIS IS NOT A BAD THING. I have done some tests with the animorphic adapter for a short film we will be shooting next month, and I can't tell you how badly that will have the moire patterning on an NTSC display. Again, I look at this as a good thing not a bad thing. The easiest way to get rid of this is when viewing the clip on a display monitor, I identify the offending clip, and add a slight horizontal blur to the footage, in affect, turning the footage from the thin line resolution to the thick. On a standard defeniton TV you cannot tell the difference. Be happy that the camera has that kind of resolution, it really is not a bad thing. The XL2 looks like a great camera and I have seen some fantastic screenshots. IF you really think about the marketing of this camera, the moire pattern should never be topic. It is being marketed to higher defenition TV (ie 16:9 native resolution) and to film makers, (the more resolution the better).

Stefan,
I used a DVX100A for 9 months and with the anamorphic adapter for 3 months and NEVER experimented any bad artifacts like the ones i see on Clive's grab frames, NEVER.
I have used "thick" and "mid" and "thin" for broadcast applications without any problem. no joke.
"thin" v detail setting has the best resolution and i use it for broadcast applications without any problem.
So this IS NOT normal for a good DV camcorder.


So i think that there are only 2 possibilities in this case (XL2 grabs):

1-Or the XL2 have a real big moire problem.
2-Or the upsampling algorithm (converting 720X576 to 1024X576) is very bad.

i just can't imagine that Canon would release a camera with that kind of problem so i think it has to do with the upsampling algorithm that Clive used to post those grabs.

...but if it comes from the camera, then it is not funny at all...

that's why i want to see full quality JPEGs in native 720X576 res.

Antoine
I would have to agree with you that I have never seen a patterning problem like the one that Clive has posted, however, Higher res footage ie adapter and thin settings do produce some strange flickering when shooting certain patterns, ie. bricks fences etc. I have never seen it look like it does as the grab is posted, however, like Clive said, there is a filter applied to it and that cannot truthfully portray the optical pheonomenon that is seen through an interlaced televion. I hope that this really is the case, as I doubt that canon would release a camera that looked that bad on interlaced television.

Antoine,

I don't think it's anything to do with the the upsampling algorithm. I have no problems in exporting 720 x 576 to 1024 x 576 - this is normal to get 16:9 export still from anamorphically squeezed PAL - it should not look bad.

The reason this still looks so bad is given by Clive himself - he captured it into Media 100 via composite analogue - when he should have captured it as native DV.

Best regards,
John.

Clive, why haven't you posted an image captured in native DV as requested? It certainly would help put some issues to rest.

Jay

Possible explanation
 

Well I guess the moire problem is not connected nor with upsampling of the image into 1024x748 nor with any TV or PAL issue.

I bet it has something to do with deinterlacing method. As interlaced material doesn't have a moire, and "progressive" has I would turn the spot on the fact that there's something wrong in the way in which the camera does "progressive" scan.

Look at the lamp in http://www.showreel.org/XL2/morray.html
The interlaced one is smooth, but the "progressive" one is jerky. The jerkeness is very similar to the look of interlaced footage treated with deinterlacing algorithm which IS NOT the same as true progressive scan of the image.

My bet is XL2 DOES NOT utilize the true progressive scan (as in DVX100), but is rather something like "frame mode" in previous models.

Can I refer you to a frame grab I made in Progressive scan and with Cinegamma?

http://www.simplydv.com/Reviews/cano...2_popup10.html

If there was to be a problem with moire, I would have thought it would show up on the slates on the roof.

However, I have heard from Canon that the beta version of the XL2 which people were playing with was probably only at 85% of the final picture quality that we can expect in the release models ;-)

Robin
SimplyDv.com

guys,

...captured via analog with media 100...OK, didn't know...
...and yes, i too believe that the deinterlacing method may produce such results....

"My bet is XL2 DOES NOT utilize the true progressive scan (as in DVX100), but is rather something like "frame mode" in previous models."

I think there is little doubt that the XL2 uses true progressive scan - look at the resolution of Robin's shots.

Again it has nothing to do with deinterlacing either - the break up on the lampost and sign is diagonal. It is clear to my eyes that it is simply a low quality composite analogue capture, and that is confirmed by what Clive has said.

It is exactly the sort of artifacts I see on my monitor when the picture is turned to composite rather than component or s-video.

Best regards,
John.

<<<If there was to be a problem with moire, I would have thought it would show up on the slates on the roof.

The funny thing about moire is that it only shows up a certain pattern frequency/ chip resolution frequencies..lets call it the M-factor...The way to test it with a video camera is to find a suspect pattern and zoom through a range of focal lengths....depending on the pattern, a moire pattern will appear, change, disappear, and possible reappear....the greater problem, is, as clive found...moires will occur at different times depending on the output device...the viewfinder, monitor, or computer screen...because they all have different resolutions (ie screen frequencies).

The thing to remember is that moire is a natural expectation given this type of image capture. The fact that the xl2 resolves at a slightly higher level make it more likely to "see" the offending patterns, and thus will perhaps, in some situations, create a moire pattern in situations where the lower resolution xl1s wouldn't have (and transversly, not produce moire in situations where the xl1s would have). The second thing to remember is that the problem is much worse at the output end, as monitor resolution is typically quite a bit lower than the aquisition resolution....as clive's image shows us....we see it on the monitor version(I still don't know how he created this), but not on the actual image.

Barry

John, Antione, and all who are concerned with the method of capture. Read Clives comments and you will find that the method of capture is irrelevant because Clive wished to show an "Impression" of what he saw in the camera, and on the video monitor. And all other faults, problem areas are to be ignored because they ARE, as Clive admits, a product of the capture. This does not present us with any greater an oportunity to assess the footage because visual "impressions" or representations are not really telling us much. However, understanding this might help us to stop chasing our own tails.

"However, understanding this might help us to stop chasing our own tails."

I think this is unfair Bill.

Firstly if there is a serious moire problem with the XL2 then the only result that matters is the full quality end one - i.e. native DV capture.

Secondly if we are talking about a problem with the viewfinder LCD and composite out to a monitor whilst shooting, then let's be clear about that.

I often shoot on the XL1s with an external monitor attatched to the composite out of the MA200, and this kind of thing is common, plus things like moire do become accentuated. It's not ideal but I have become accustomed to being pleasantly surprised when I finally capture the footage into the NLE.

Best regards,
John.

John I think you misunderstand my intentions. I agree, there is a need for
an actual, true "this is exactly what was recorded" type of thing, and not what Clive has admitted to as being an interpretation of what he witnessed. An "interpretation" that could just as well be a pen and ink sketch as far as I'm concerned. And yes, you are correct, a native DV capture would do the trick- or at least it should be enough for a fair(er) analysis. But, taking this into account I have no idea why anyone would bother with this CREATED "representation" no matter how it was captured. On another note the gull looks superb and apart from moire testing, the smoothness of the background is very telling, not to mention other factors like the detail and highlight rendering etc. Clive is in a position that demands a more accurate approach than simply trying to describe what he feels is an issue. We need head to head comparisons and other fair methods of assessment.
All the best.

This thread is starting to chase it's own tail. If we read Clive's last post, he says he is leaving the discussion.

"This thread is starting to chase it's own tail. If we read Clive's last post, he says he is leaving the discussion."

Sorry Jeff, perhaps it is over until he responds further, but I thought it was quite interesting and it seemed to me that Clive left without answering the key question.

All he has to do is provide a native DV capture of the same image - then we can properly judge if the XL2 has a more than unusual moire problem.

Best regards,
John.

yep, easy...

just post a native DV grab frame...

Hi guys.

Just thought you'd like to know that I've finished my test of the XL2 for Showreel and I've managed to figure out how to eliminate the moire patterning that was evident when shooting in 25P mode. The magazine is at the printers today and we'll be out next week. As to my knowledge we are the first magazine to complete a full test of the camera, my publisher has agreed to send to article in pdf form to international subscribers at the
same time as it's received by UK subscribers, as international subscribers usually receive it a week or so later.

If you are interested, please email denise@showreel.org."

Clive--

Why haven't you posted the native DV capture as so many of us have requested? Sure would like to see it!

Thanks.

Jay

Sorry. Been busy lately.

Will post in a minute.

Clive

Thanks for your information and feedback regarding the xl2. What was your solution in eliminating the moire patterning in the 25p mode?

Barry

hi everybody...
 

What happened to this section ? no anwers....if clive left...somebody who has xl2....doesn't they observed anything about moire pattern.? Or no one is going to answer . This dv community is becoming fireworks...after releasing canon xl2.....
we fight about 8 bit .....found a solution lately but its 12 bit.
now with this image pattern issues.......no solution or hiding...may be canon guys might be observing this forum carefully.. might be coming with an answer..well....its hot in jamaica...everybody is hot for canon xl2....... well thanx buddies and folks.........

vamshi

varnshi

glad it's hot in jamaica...its nice, but not too hot here in california...

repeat after me....there is no moire problem...there is no moire problem...there never was a moire problem.....


hope this helps.

Barry

hi barry
 

Sorry barry................i cant follow you in your band wagon....

keep cool my xl2 is coming soon.....if i observe....this pattern/that pattern ....you are going to buy my camera....?

<<...you are going to buy my camera....?>>

Varnshi

sorry...got my own on the way...no money back guarantees here at dvinfo.net.

Look...if you read through the thread you'll see a pretty good consensus amongst the more experienced voices that moire is a fact of life with all video cameras, and it has always been this way ....If you should stumble upon some with your new xl2 (which you probably will if you look hard enough) then you are in good company...(go grab two pieces of window screen and overlap them...see if you can do it without some secondary pattern --moire-- being formed.) This is exactly what you are doing with a video camera when you photograph a brick wall, or a set of venetian blinds...or a window screen. Monitors, tv's etc are even more likely to introduce moire (in fact as clive's stills show...they will show moires even when there isn't one in the camera image).

IF, and this is definitely an if.....the xl2 exhibits a higher degree of moire than another camera then it is simply because the xl2 is resolving at a higher, better, level...which is what we all keep saying that we want.... DVX users have had to deal with similar issues relative to line twitter ( a form of moire) as the resolution of the camera in progressive mode is simply higher that it needs to be for SD monitors (but play it back on a HD set and you'll watch the patterning go away and swear the image is HD).

Varnshi...if you get moire in an image, there are several strategies for dealing with it...and they are detailed earlier in this thread. Its your job as a videographer to understand not only how good your medium is, but also its shortcomings and limits, and to take the appropriate steps to avoid those shortcomings.

I think I'm out of hot air for awhile.

Cheers

Barry

Doesn't sound like hot air to me -- sounds like an experienced operator who definitely knows what he's talking about. Thanks as always Barry,

<<IF, and this is definitely an if.....the xl2 exhibits a higher degree of moire than another camera then it is simply because the xl2 is resolving at a higher, better, level...which is what we all keep saying that we want.... DVX users have had to deal with similar issues relative to line twitter ( a form of moire) as the resolution of the camera in progressive mode is simply higher that it needs to be for SD monitors (but play it back on a HD set and you'll watch the patterning go away and swear the image is HD).
>>

This is an interesting point Barry. I've actually never viewed any of our work directly on an HD monitor because...well, I've never shot in HD. Are you saying that, in theory, Xl2 footage will look similar to HD on an HD monitor?

Similar, no...if you put a good HD source next to DVX footage the difference is clear. But you'd be surprised how good DVX progressive footage looks on an HD set. Especially in limited movement, relative close-up type shots...like interviews. It certainly looks as good as the compressed HD streams that typically come over satellite and cable. (lots of movement in high contrast situations will typically start to show some aliasing).

The point being that the DVX's 480p ( and now the xl2's) are somewhat overkill for SD monitors, and there can be a price for that extra resolution. This is why both of these camera's have detail settings that essentially lower the resolution when you get in trouble.

On a side note (actually, the original note)...I just did a camera test with my DVX on a home made moire chart...fun stuff...lots of rainbows...shimmering all over the place...guess we better recall all those panny's. Funny thing happened...I noticed that when I got a certain distance from the chart...I started SEEING moires with my eyes (no camera) --guess this is what the Op-artists were doing... my eyes must be defective too....oh I am tired....see y'all.

Barry

Howdy from Texas,

"When new lines meet your eye
from two screens as they ply,
that's a-moire."

Where strange colors now shine,
they weren't there the last time,
that's a-moire."

(apologies to Dino)

I think you need to apologise to us all for that one Chris! ;)

Aaron

Love it. Can I use it, chris?

I went home last night, and I was trying to explain this moire thing to my girlfriend--she was watching the olympics- 400m hurdles I think- and I looked up at the screen as it was pulsating like electro shock therapy from all the lane lines on the track surface...

I said, "its like that honey"...

she just nodded in that knowing way.......

Barry

hi
 

hi barry...

nice convincing factors, may be your girlfriend listerns...but no body is ready to nod like a goat....


Well Chris...

Nice poetry.....I think you should publish in the book
After all you are head to all of us...This is kiddish man.

I went to some other sites they were real ,saying that chris is the moire pattern for canon....i never believed....well....this forum is becoming foolish.....I think better to find some other forum...where i can get professional strategies....... I am saying good bye to this forum....

well wish you a good luck ,for every one....


bye bye....


vamshi