Gregg Loewen pays an ISF visit to Pennsylvania

Discussion in 'Archived Threads 2001-2004' started by Shawn Sefranek, Jan 17, 2002.

  1. Shawn Sefranek

    Shawn Sefranek Second Unit

    Sep 30, 1998
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    Like Ron Epstein and a few others, I had my RPTV calibrated by Gregg Loewen this past weekend.
    I first met Gregg last September out in California during the HTF National MEET.
    When I read on the forum that he was coming to New Jersey and had a spare day to do some calibrations, I asked him if it would be possible to take a 100-mile side trip into Pennsylvania.
    He agreed, so we set it up for him to do calibrations on both my set and a friend’s who lives nearby.
    I have a 50” Toshiba 50H81 that was purchased in August of 2001.
    I was pretty happy with the picture “out of the box” except for a few geometry errors.
    My theater room is in a basement with no windows so glare has never been a problem, but the (4) wall sconces needed to be turned off or WAY down for movie watching.
    Like Ron Epstein mentioned in his review, the major item that I was afraid of was the removal of the glare screen.
    I had visions of this ultra fragile screen element being exposed that could be damaged with a simple touch of your finger.
    While there are some concerns in doing this, it’s well worth the trouble.
    Its not like you just sit back and watch this guy work, you get to be part of the action as he does his magic.
    Gregg started by taking some pre-calibration readings of the set with some instruments that are WAY too expensive for most Home Theater junkies to have on hand.
    The “Grayscale” readings showed that my set was running a bit HOT.
    It wasn’t as bad as some he has seen, but he was getting readings of 6900 to 8300 for settings that should be as close as possible to 6500.
    The first step was to physically disconnect the SVM connections on each of the three guns.
    This takes all of about two minutes as long as you know which wires to pull from the hundreds that are inside the set.
    Next he attacked the glare screen.
    “Re-stacking” the screens made the BIGGEST difference to me.
    It only takes about 10-minutes to do if you are handy like Gregg.
    Zip-zip-zip with the cordless screwdriver and after assisting him with the swap my set was looking better then ever.
    While reducing glare is the main goal, it also allows you to obtain better black levels from the unit.
    After re-stacking the screens he had to manually refocus the three lenses.
    According to most technicians, this is impossible to do from the front of the set with the screen in place.
    Without giving away any trade secrets, lets just say they are WRONG.
    He did it without a problem with the assistance of a tool that only costs a couple of pennies.
    After the focus, Gregg noticed that the geometry was off pretty bad on my set.
    I didn’t have the overlay templates for my screen so he got out the measuring strips, strings & masking tape.
    He went to town stringing up my set for the convergence calibration.
    On some of the older sets you have to do this for each picture setting.
    On mine you only have to do it ONCE and the setting holds for the Full, Normal, TW1, TW2, TW3 & Hi-Def.
    This takes well over an hour and looks like really tedious work.
    I could see things were coming along nicely.
    He also performed the “Herman TLV Maneuver”.
    I’m not quite sure exactly what this does, but I think he said it improves the “crispness” of the picture.
    It looks kind of creepy as he adjusts the convergence lines to “bend” like that.
    After the convergence and overscan adjustments, he started to work on the grayscale settings.
    All of this was done from inside the service mode so the user controls weren’t touched.
    Gregg has one eye on the TV and the other on the laptop to see the readings.
    My job was to hold the analyzer up to the screen because without the glare screen, it doesn’t stick on its own.
    The goal is to get as close as possible to 6500K.
    The final reading showed a definite improvement
    Pre calibration readings were as high as 8200K.
    After calibration the numbers were between 6350 & 6800.
    One final tweak.
    Even though the grayscale readings were much improved there was still a slight variance when moving the color analyzer left-to-right across the screen.
    Gregg solved this with two strategically placed pieces of electrical tape over the edges of the outer guns.
    This brought the numbers into a nearly uniform value across the entire screen.
    Gregg did my friends set earlier in the day and after a late dinner break he was working till just past midnight.
    After he was done I watched some scenes from Gladiator, Fifth Element Superbit, Toy Story 2, Pearl Harbor, Moulin Rouge & Dinosaur.
    The results are simply amazing.
    I am so glad I decided to do this.
    I haven’t had much time to evaluate the set by watching an entire movie yet.
    I sold my (2) SVS Subwoofers and delivered them to their new owners this past Sunday.
    I’m anxiously awaiting their replacement “PLUS” versions to arrive in the next week or two.
    Watching a move without Subwoofers is not the thing to do even if the picture is beautiful.
    If Gregg lives near you or is planning a “tour” to your area, give him a ring and you won’t be disappointed.
    Thanks again Gregg, I appreciate your hard work.
    If I missed anything or described something inaccurately feel free to correct me here.
    Shawn S
    PS……Here are a few pictures I took while Gregg was operating on my set:
  2. Gregg Loewen

    Gregg Loewen Video Standards Instructor, THX Ltd.

    Nov 9, 1999
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    New England
    Real Name:
    Gregg Loewen
    argh!! the dreaded strings...

    The new toshs are quite kewl as convergence is the same in all the modes. So I figured since I was staying the night anyways, we might as well get it dead on and out came the string...I think Shawn's picture gave a good depiction of the event. The good of this is perfect geometry nad no need to do image centering and overscan. The bad is you have to settle for 5% overscan when you can actually get the toshs down to 2-3 % (does the difference really matter??).


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