Mechanical lens focus: WOW! and easier than I thought!

Discussion in 'Archived Threads 2001-2004' started by chris larralde, May 13, 2001.

  1. chris larralde

    chris larralde Stunt Coordinator

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    Since I'm holding off on the purchase of a new 16X9 set or projector, I decided to tweak my 4X3 Tosh TN50X81 as much as I could.
    I've already corrected geometry, 64pt convergence, duvetyne, lens hood, Avia, electronic focus, and general cleaning for dust etc. The only thing left was a mechanical focus of the lenses. I've been holding off because it just seemed too complicated. Well, I was wrong! [​IMG]
    I used the string method and found that my red was off by quite a bit, green was pretty good, and blue was okay. Fixing the red really sharpened things up. Everything is much clearer now. The only drawback is that the crawlies on anamorphic DVDs look more pronounced now. I'm using a first generation progressive player (tosh 5109) and judging from other posts, I'm suspecting that this may be the culprit. I also noticed that sharpening the blue added a yellowish tone to the the whites. I read about this on Chris White's site (I think), and I'm going to decide whether or not I'll need to re-adjust the blue.
    Well, aside from adjusting the grey scale, I feel that I've maxed out the potential of my set, short of a full ISF calibration. [​IMG] I have to say that I'm quite pleased -- this should make my wait for a new set/projector much easier. [​IMG]
    The only thing I'm questioning now is the DVD player. Does anyone know how the new players compare to the first ones? I keep hearing about this "genesis" chip -- what the heck does it do? Do the first gen players have it? Will the new players eliminate all the nasty downconversion crawlies that I see?
    Thanks for any comments/suggestion on the DVD player-- and for those who haven't tried the mechanical focus, I would highly recommend it.
    chris
     
  2. Brian_Reynolds

    Brian_Reynolds Auditioning

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    Can you define "crawlies"?
    Since I focused my Sony 53HS10, I have noticed that skin tones are somewhat "grainy". Especially when they move across the screen. It's almost looks like the screen has a grit to them. This is while viewing DVD players. It is also apparent while viewing cable, but it is so bad with cable that I assume it's just the DRC (Sony's line doubler) making a mess out of a poor signal. [​IMG]
    Is this what you would refer to as the "crawlies"?
    Thanks!
    Brian
     
  3. chris larralde

    chris larralde Stunt Coordinator

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    After doing some research on my Toshiba 5109 progressive DVD player, I've found posts indicating bad 3:2 pulldown and a chroma bug. Both of these things make reds streaky and "shimmery". When watching anamorphic films on my 4X3 HD ready set, closely spaced lined jump around and "crawl". Now that I look for it, it's really driving me nuts.
    I was watching Fifth Element last night on a DLP front projector through a PC, and the above mentioned effects were non-existent.
     
  4. MarcS

    MarcS Stunt Coordinator

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    I assume your 4:3 Tosh does the "squeeze" trick?
    While the Tosh 5109 does have the chroma bug, so does almost every other player made...if I recall the articles on this issue correctly, only a few players don't have the chroma bug. Additionally, from the postings showing examples of the chroma bug, it seems to be detectible in only some movies, specific scenes, and then only if you are looking very closely.
    I have to wonder if what you're seeing isn't maybe related to your set doing the squeeze trick?
    I'm using the Tosh 5109 on a Pioneer SD582, and don't see the effects you mention...
    How do you set up your 5109? Do you tell it your screen is 16:9 or 4:3?
    Have you looked at the stadium scene in VE (or is that AVIA)? Are the seats smooth looking during the pan, or do you get jagged lines there? They look perfectly smooth with my setup...
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  5. chris larralde

    chris larralde Stunt Coordinator

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    My TN50X81 doesn't squeeze the picture. I leave the player on 4:3 since 16:9 compresses the image. In fact, when I view sources through 16:9, I don't see any of the artifact problems.
    Sounds like I need a new tv [​IMG]
     
  6. RyanDinan

    RyanDinan Stunt Coordinator

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    Actually Chris, 16x9 mode on your DVD player outputs the video untouched, as it is on the disc. The 4x3 letterbox mode on your DVD player is removing lines/interpolating and adding black bars to adapt any anamorphic images for your 4:3 set.
    Other than that, your DVD player doesn't squeeze/compress anything. The TV is resposible for displaying an anamorphic image correctly - They do this by drawing their scanlines closer together vertically. In video, there's no such thing as "un-stretching the picture".
    The artifacts you are seeing are most likely caused by the 4:3 letterbox conversion in your DVD player.
    -Ryan Dinan
     
  7. MarcS

    MarcS Stunt Coordinator

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    That confirms my suspicion... you've got a progressive output player, but can't use that capability. The 5109 does not do letterbox conversion very well, other less expensive players do it much better...
    Keeping the player and getting a new tv sounds like a great plan! [​IMG]
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  8. chris larralde

    chris larralde Stunt Coordinator

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    Which of the newer players would be recommended for letterbox conversion? I've heard Toshibas aren't the best.
    chris
     
  9. MarcS

    MarcS Stunt Coordinator

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    I did a quick search of the forum for "downconversion" and found this thread:
    http://www.hometheaterforum.com/uub/...ML/037386.html
    I'd suggest doing a similar search here, and maybe on home theater talk forum, and AVS forum.
    But...people do like the Panasonic models...
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  10. Carlo Medina

    Carlo Medina Executive Producer

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    Chris, Toshiba drops every fourth line of resolution. Thus you get a sharp picture - but when straight lines or text are scrolled vertically you get "jaggies" as every fourth line is omitted.
    Sony uses a mathematical process that combines 4 lines of res into 3. What that does is give you a stable picture (no jaggies) but at the cost of a softer picture overall.
    Some say the Panasonics are better, but the only one I've seen (the old A110) used a process similar to my old Toshiba. I've been happy with my 2 Sonys ever since I gave my old Tosh away. The ultimate remedy is to get a TV that does the squeeze trick or a 16:9 set--which I'm about to do next month.
     
  11. chris larralde

    chris larralde Stunt Coordinator

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    This is a little off topic, but since were talking about DVD playback ... how come anamorphic, and non-anamorphic DVDs look equally as good on a DLP front projector?
    When standard letterbox movies are upsampled (or stretched?) on a 16X9 set, they look terrible. On my loaner DLP, they look super. In fact, I can't really see the benefit of the anamorphic transfers at all. To top it off, I get no motion artifacts on any of the disks I've viewed. BTW the projector is an Infocus 425z (800X600).
    chris
     
  12. chris larralde

    chris larralde Stunt Coordinator

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    Ooops, forgot to mention that I'm running the DLP off of a Mac G4 with resolution set at 600 x 800 with a 60hz refresh rate. [​IMG]
    chris
     
  13. RyanDinan

    RyanDinan Stunt Coordinator

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    Chris,
    The reason why you don't see a difference is because a DLP projector uses a set amount of pixels to draw the picture. In order for the DLP projector to display an anamorphic image, it needs to do some interpolating to display the image in a 16x9 aspect -This means throwing away lines of resolution. An anamorphic and letterboxed version of the same DVD will use the same amount of pixels on a DLP/LCD projector, as they are unable to "squeeze" the vertical resolution like a CRT. They only have a set, fixed amount of pixels to work with, whereas a CRT can squeeze their scanlines together vertically, to allow for more resolution. The only way to get the benifit of an anamorphic DVD on a DLP or LCD projector is to use an anamorphic lens, much like how a movie theatre projector works.
    Hope this helps,
    -Ryan Dinan
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    [​IMG]
     
  14. Randy Boecker

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  15. chris larralde

    chris larralde Stunt Coordinator

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    Well, jeez guys ... after a week of torturing myself, I went ahead and re-ordered the Toshiba 56H80! [​IMG]
    This has been the most indifferent week of my life! I ordered a 56H80, then canceled it. I then had my sights set on a front projector, but my wife canned the idea when she saw it hooked up. So in despare, I tweak my 50X81 and decide that it looks so good that I have to get a 16:9 set! [​IMG]
    Well, it's arriving tomorrow morning and I can't wait. The knowledge that I've gained from this site has convinced me that I've made the right choice and that I will be able to reach nirvana with my set -- I can't wait to get it set up and properly calibrated.
    For now the 5109 is going to stay -- If the artifacts still bug me, then I'll look into upgrading the player. Until then I'm going to enjoy 33% more horizontal resolution! [​IMG]
    This is truly a disease!
    chris
     
  16. Timmy

    Timmy Stunt Coordinator

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  17. RyanDinan

    RyanDinan Stunt Coordinator

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    Randy,
    Could these artifacts be the chroma upsampling bug found in most DVD players (Toshiba included)? Panasonic players are one of the few that don't have the chroma bug. If you know someone with a Panasonic, ask if you can borrow it, and see if the artifacts are there.
    -Ryan Dinan
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    [​IMG]
     
  18. Jim Christian

    Jim Christian Stunt Coordinator

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