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Okay, so I understand the SD, but what's a scanline?


Is there a good description of scanlines in the forum somewhere? I can't seem to find one. People talk about them for the AE300, but nobody seems to be able to put their finger on what causes them. Lots of talk in the forum of the up-and-coming release of the AE500. People have been concerned about whether this machine will demonstrate the same error as it's predecessor, the 300. So what exactly is a scanline and can it be fixed?


:confused:
 

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First off, I believe the whole scanline issue on the AE300 has been blown way out of proportion.


The simplest way of explaining a scanline...a brief and I mean brief screendoor effect on part of a image (usually light in colour) ie. sometimes I can see it if they do a fast pan on a actors face.


I think that the smoothscreen technology works so well that any imperfection is picked up on immediately. I have had this projector since Oct of last year and am still amazed at the picture it produces. I rarely see the scanlline artifact unless I am programmed to look for it. Sometimes I think this forum is as much of a curse as it is a blessing....we seem to spend so much time trying to pick out any minute flaws in our beloved projectors and harp on them forever.


I have a buddy who spent $4000 on a rptv Sony and he kicks himself every time he comes over especially on HD material.
 

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I agree that the "scanline" issue has been blown out of proportion. I see it pretty regularly, but it doesn't interfere with my enjoyment of the projector.


"Scanlines" are a deinterlacing artifact where the projector picks the wrong deinterlacing scheme. When large areas change brightness, the effect is noticeable because alternating lines of light and dark show where the projector picked odd lines from one frame and even lines from the other frame. The effect is better known as "combing" due to the way edges of objects look when they move horizontally. The AE300 has a pretty poor deinterlacer, so it's better to feed it a progressive signal whenever possible. This doesn't really bother me, so I watch a lot of DirecTV (interlaced) on my AE300.


I can demonstrate the artifact at will with an interlaced source. Cartoons are particularly good for this, since they have large areas of a single color which switch quickly to another color. And any satellite channel with horizontally scrolling text will show combing.


When using a good progressive scan DVD player (Panasonic XP30), I almost never see the artifact.
 

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The "scanline artifact" is a deficiency of all LCD projectors to some degree. I have seen it on my Z1(and reduced it) as well as on a Panny 75U, not to mention many other LCD non-projection devices. It has nothing to do with deinterlacing of a non-progressive source. I use a Panasonic CP-91 with my Z1 and still see it on vertical pans. I know what triggers the effect and it is slow vertical pans, but do not know the cause. The "scanline" looks just like the description. It appears to be a dark grey or black line that appears horizontally in the image, just like a scanline on a CRT. It can actually be seen if the PJ viewer moves his/her head up and down slowly on a solid colored screen(doesn't have to be, but it becomes easier to see that way), even if the image is paused. It is a nuisance, but it is inherent in the technology...at least to this point.


Bricktop
 

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Good words Bricktop. The scanline artifact has nothing to do with deinterlacing. I see the artifact all over the place on my L300u with a progressive signal from a RP82. I've seen this scanline artifact on every single LCD PJ I've ever seen including the HS-10. There was a very technical explanation given for this a few months back. I believe it was by Guy Kuo but I could be wrong about that. Wish I could remember the main gist of it.


Brent
 

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I have probably one of the most "picky" set of eyes in existence and I **ALMOST NEVER** see Scanline artifact anymore. You simply need to do the flicker tweak and MAYBE a slight defocus. You won't see it anymore. :)


I do see vertical banding though (and it drives me nuts!) :(


-Tim
 
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