1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Vertical line structure on MT3

Discussion in 'Projectors, Screens & Video Processors' started by cg999, Jul 31, 2001.

  1. cg999

    cg999
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I recently purchased a Toshiba MT3 projector having agonised over deciding between the Sanyo PLV-30 and the Tosh MT1.
    The detail and colour reproduction are (in my humble opion) excellent and it even does a good job in the contrast department. My only concern is a vertical line structure which is usually very obvious in sky scenes and dusty scenes or parts of the image that are out of focus (in the background.)
    My question is to any other MT3 owners: is this a trait of the projector that I have bought (and I'll just have to get used to it) or is there something that I can do about it? I am usig a 7m S-VHS lead and a cheap (£120 manual) screen. Any help greatly appreciated!
    (It's strange that the reviews of this projector in HCC and What Video & TV didn't mention anything regarding this problem.)

    Thanks

    CG
     
  2. Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    This is something which often shows up on lcd projectors.<br />I get this a bit on my MT1.<br />Nothing to my knowledge will remove it.
     
  3. Paul O Hale

    Paul O Hale
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    It occurs on some LCD projectors but not all, also it can vary between models and is not dependent on resolution.<br />The vertical lines you describe in this case generally come from the drivers to the pixel array on the actual panel itself, this can vary from panel to panel its not a fault its just tolerances of the semi-conductors.<br />This is not to be confused with screen door which is an entirely different phenomenon or with scaler artifacts
     
  4. Paul D

    Paul D
    Well-known Member

    Joined:
    Dec 27, 2000
    Messages:
    2,620
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Manchester
    Ratings:
    +391
    The faint vertical lines was a problem on my MT1.<br />Using Svideo made the effect worse.<br />I found when using a HTPC the effect was vertually gone.(But not totally)<br />If you can, either get a RGB or Component to 9 pin "d" lead, avoiding Svideo.<br />I believe the effect is cause by something called "Pixel Addressing".<br />Depending on the size of the LCD panel, groups of pixels are grouped together ie on a 800x600 panel the grouping could be every eight vertical pixel row(approx). Depending on how well the phase shift matches this depends on how obvious it is.<br />Go right up to your screen whilst showing a paused picture which shows the effect. You will notice every eight to twelve vertical rows "approx" will be slightly darker. Ie if yours is every eighth row it will be EVERY eighth vertical row that will be darker.<br />My Sony LCD can show this effect, but due to the pixels being so much smaller and the effect being so slight it is only noticeable when stood within a couple of feet from the screen.(and then only on a blue screen!)<br />This was the first thing i checked out after swopping the Toshiba. I was over the moon when i could finally stop cringing when a sky/dull scene etc came on.<br />Cg, try the above things ie RGB/Component or a HTPC to try to minimise the effect. You could make sure the "Phase" adjust is correct in the setup menu, as this may be making the effect more obvious.<br />I agree with your comments about HCC/WTVAV not mentioning this obvious defect. I read and reread every article on the MT1 and not once did any review mention it...<br />I believe i would still have a MT1 if this effect was not present.
     
  5. cg999

    cg999
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    "If you can, either get a RGB or Component to 9 pin "d" lead, avoiding Svideo.<br />Cg, try the above things ie RGB/Component or a HTPC to try to minimise the effect. You could make sure the "Phase" adjust is correct in the setup menu, as this may be making the effect more obvious."

    <br />Thanks Paul

    Please forgive my ignorance, but I'm not familiar with the leads you mentioned. I think that the component lead you refer to has the three jacks coloured red, green and blue on one end and a "computer monitor plug thingy" (please forgive my very technical language) on the other end. However my DVD does not have component out so this is no good to me. The other leads u mentioned are totally unfamiliar to me.

    Also the Phase adjustment is not available, I assumed that this was because I am using Svideo in.

    Conor

    [ 01-08-2001: Message edited by: cg999 ]</p>
     
  6. Paul D

    Paul D
    Well-known Member

    Joined:
    Dec 27, 2000
    Messages:
    2,620
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Manchester
    Ratings:
    +391
    Cg999,<br />You may have to upgrade your DVD player to one with component out.<br />If you do decide to upgrade it may be worth your while getting one with progressive scan.

    Keene electronics do the component(three phono plugs) to computer "D" connection as a custom lead.

    One thing you could try is the "Iscan Pro". As far as i'm aware it converts any input ie Svideo/Composite/component(but NOT 15k RGB) into Component or "Computer" type RGB. Therefore you would get the best of both worlds, progressive scan and being able to keep your existing DVD player. As a bonus the Iscan would also work with other inputs ie sky/video etc.

    Otherwise your only other option would be as suggested is to use a HTPC etc. With a "computer input" (either Iscan or PC) the phase adjustment becomes enabled.

    Even after all that there is no guarantee that it will get rid/reduce the vertical lines, but it would inprove the picture!.<br />Good luck...
     
  7. Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Out of interest, will the phase adjustment really make a difference?<br />What does it actually do?<br />Ive never tried altering it.
     
  8. Paul D

    Paul D
    Well-known Member

    Joined:
    Dec 27, 2000
    Messages:
    2,620
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Manchester
    Ratings:
    +391
    I adjusted the "phase" when using my HTPC by going to "start" (in Windows), select "shutdown". The screen goes very stripey. Adjusting the phase changes the vertical stripes until they are even very thin vertical stripes, rather than thick unsteady vertical bands.<br />On my MT1 the vertical stripes during films were much reduced.<br />It may just have been that they were less noticeable due the picture being so much more detailed.<br />I hope this is of some help!.
     
  9. Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Thanks I'll give it a try. Yet another setting to play with. Great stuff! <img src="biggrin.gif" border="0">
     
  10. cg999

    cg999
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Well I have been very busy trying out various things based on ideas spawned from some of the suggestions above. The first thing that I tried (in an effort to reduce the vertical line structure) was to try a very high quality and much shorter (1 mtre) S-VHS lead. This was a suggestion made by the guy from who I purchased the MT3. (It's amazing how friendly he was when I was buying the projector, and how unfriendly he was when we spoke last week, it just don't figure). Anyway the new S-VHS lead led to no improvement at all.

    Next I dragged my PC from upstairs and planted it on a stool (precariously) within reach of the projector. This allowed me to use the RGB input, and yes indeed there was a marked improvement. My problem now is that my DVD player does not have component out, so in order to benefit from this new knowledge I will have to go the expense of purchasing a new DVD player and 7 metre component to computer RGB lead.

    One (of two) concerns that I have is that I am not sure if the 16:9 mode was working using RGB in. So if anybody is sure about this please let me know. The other is that the (very very sad) owners manual stated &#8220;If NTSC/PAL/SECAM signals are input to RGB INPUT connector, they cannot be displayed&#8221; (That's a quote by the way, despite the little blood in my alcohol system, my English hasn't quite degraded to that level yet)

    So if anybody knows anything about the 16:9 mode and/or NTSC/PAL/SECAM signals with RGB input on the MT3, please fill us in.

    Thanks

    Conor
     

Share This Page

Loading...