Big Miscalculation

Discussion in 'Projectors, Screens & Video Processors' started by Gadjet, Sep 14, 2007.

  1. Gadjet

    Gadjet
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    Hello everyone,

    I have made a big mistake in buying aa 8ft screen. I am too close to the screen so my HD picture now does not look so good. Cannot move seat back any more and zoom missses out part of picture.

    But the main problem is the projector (Panasonic AE1000) cannot focus out anymore and the picture does not fill the screen, looks bad and is annoying, especially watching Sky HD football.
    So my big question is does anyone know of any black material I can stick to screen to reduce picture viewing size?

    PS screen cannot go back back due to no fault problem

    Hope there is an answer,
    Phill
     
  2. Fred Flintstone4

    Fred Flintstone4
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    Hi Phill, you have my sympathy. I'm always buying stuff to find out that it's not quite right. Bought a USB Skype phone for my friend only to find out that she's got a Mac, not Windows. So I bought a WiFi Skype phone only to find out that she doesn't have a hot spot... Story of my life!!!

    I don't know what are your dimensions: throw needed, throw available etc but there is one way round the problem - mirrors! Or one mirror to be exact. You would need one front surface mirror of the right size, change your pj onto rear projection and "fold" the beam path from your pj. I've done quite a few mirror installs and if you're up for it then I will tell you how to do it. It's easy and it'll be a major talking point...
     
  3. rocketron204

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    Hi Phil,
    I'm thinking of buying a similar set up to you, according to my calculations I should be able to get an 8ft screen image from around a 9ft throw (from the lens of the projector), I'll be sitting right under the projector.
    I would be gratful if you could tell me how far away your screen is from the projector and how far away from the screen you are sitting and what exactly is the problem with the image.
    Also is the noise of the projector a problem?

    Thanks Ron
     
  4. KelvinS1965

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    If I understand correctly, you have two problems: You are sitting to close to the screen and the PJ can't zoom the image to fill the screen? If you could move the PJ to the back of the room you might have my problem, where the image only just fits on the screen at minimum zoom. I'd guess though that the PJ is as far back as you can put it?

    If you want to reduce the size of the screen, a suggestion might be to get some black speaker fabric from Maplins and maybe put some velcro on the screen casing with double sided tape. Then attach the two pieces of fabric once you've lowered the screen, maybe fix the matching half of velcro to the material with contact adhesive or similar? You can also not lower the screen to it's full drop and use even wider side pieces. I actually use a 120" screen that I only lower enough to give me a 2.35:1 visible screen.

    I'm surprised that you find the picture on Sky HD is poor. I only have BBC HD from my PC, but that looks pretty good to me. I view my 120" screen from 4 metres back (mixed measurements sorry:D). Have you tried calibrating the AE1000 using the Sky HD calibration program with Mylene 'what's her name'? If you have the brightness up too far, for example, it might highlight noise in the picture. The other thing to try is using a neutral density filter to dim the picture. This gives better blacks and makes the picture less dazzling; I prefer it, but others might not. Hoya 77mm ND2/4 coated glass filters (not cheap resin that reduces contrast) cost approx £20-25 on line.
     
  5. Gadjet

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    Hi,

    The distance from the screen to the projector is 9ft 10. There is roughly 2" screen between the black border of the screen to the picture edge.
    With Sky HD using full screen it stands out more. Sorry if it come accross wrong but Sky is a great picture but does not look as clear as 6ft screen due to as you say being too close to the screen for the size that it is.
    Films dont look as bad that are letterbox picture so only the side of the picture does not reach the black border.
    So I will look for a black thick sort of tape to place around the screen to take away that anoying missing part of the picture as the pj is as close to the wall as I can get it with HDMI lead coming from back.
    Really p....d with myself for not thinking it through and just thinking bigger is better without thorough thought.
    Ron hope you can get enough distance to choose right size screen you want
    Phill
     
  6. Fred Flintstone4

    Fred Flintstone4
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    Hi Phill, do you know how much extra throw you need to get that extra 2" picture width? Presumably that's an increase of 2" either side so you're looking for 4" altogether. With a normal lens you're only looking for an extra 8" or so.

    I wasn't kidding when I suggested mirrors. One of the first LCD projectors, which I used to sell, had no way of switching the projector into rear projection mode. It seems that the back room boys thought that everybody wanted front projection only. Consequently somebody came up with a small mirror, about 6" x 4" which was fitted with a bracket that attached to the front of the projector. The projector was then place at 90 degrees to the screen with the mirror at the horizontal centre at 45 degrees across the lens. This produced a laterally inverted picture on the screen. How will this help you? If you set your pj to rear projection then point it at a mirror then, depending on the size of the mirror, you will lose the length of the pj from the throw equation as the pj will be along the back wall. If you try it with a normal mirror and find a way of permanently mounting the mirror and then you can replace it with a front surface mirror. These are available from specialists and if you're interested then I'll let you know where they are. They might even give you a small offcut.
     
  7. Gadjet

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    Cheers Walter,

    Waiting for new subwoofer to come as well now so my budjet is to the limit. Idea sounds good but would this slightly deteriate the picture quality?
    I think for me to fill the screen I need to go back 8" from where my pj is set into roof.

    Thank you for the thought Walter :smashin:,
    Phill
     
  8. Fred Flintstone4

    Fred Flintstone4
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    Hi Phill, the installations in which I have used mirrors have not brought any adverse complaints and that includes broadcast television studios (they are notorious for underestimateing the throw distance required so you are in good company!).

    A front surface mirror will lose you some brightness but with modern pjs I don't think you would notice. I am used to doing it with CRT and laser projectors, not today's single lens pjs. You can get fs mirrors on 6 mm float glass for a reasonable amount of money. You can also get them on foil, they weigh nothing but looking at the size of mirror you require I would stick to 6 mm float glass (the biggest I used was 300 cms x 150 cms). Both types of mirrors usually have optical coatings designed to reduce the amount of loss, not that you will notice it. If you want to know the calculations to work out the mirror size then I would be more than happy to tell you, it's really easy and anybody can do it (I do...).

    Out of the options that you have available (stick black bits on your screen - you must be joking, different screen - cheapest, different lens on the pj - expensive, different pj - ouch!, move the back wall...) it's one of the cheapest and one of the most elegant. Most people will want to know how you did it and you can say "It's all done by mirrors!" Just try putting a small mirror in front of your pj and you'll see how ridiculously easy it is. You have no convergence problems as that's done in the pj. Put the pj parallel to the back wall and the mirror where the lens would normally be (horizontal centre) - easy. By the way, I'd love to sell you a new, smaller screen but I do have a conscience!
     
  9. rocketron204

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    Hi Phill,
    sorry about the late post but I work away from home and have only just got back:clap:
    Is the 8ft measurement diagonal or across the width?
    It seems like the most popular size screens are 92 inch diagonal (80 x 45) or 106 inch diagonal (92 x 52).
    According to the Panasonic web site the screen size from 9 ft throw is 92 inch diagonal.
    You should have a maximum 100 inch diagonal (87 x 49) image from a 118 inch throw or am I missing something.
    I can't take the projector back any more than 9 ft because of a wall so it would have to be a 77 inch (67 x 38) screen if my info is wrong.

    If I eventually go for a projector instead of a bigger plasma (been saving and looking for months) all the cables and sockets will be sunk into the wall so its a lot of work if I'm not impressed with the set up.

    Is it really worth the hassle?

    Ron
     
  10. Azzin

    Azzin
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    Yes. :smashin:
     
  11. tonymotty

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    The wall.......is it an outside one...if not then a little hole in it and it will be like being at the movies!!...esp if you put a piece of expensive optical glass over the hole to keep fan noise out. Tony.
     
  12. binbag

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    Or just paint the screen down to the size you need...

    Set your pj up to project the ideal size for you on your too big screen. Mark the projected area and take the screen to somewhere where you can spray paint it - easier to do if its hanging - get a few large cans of matt black car spray paint (I used Halfords). Mask out the area you wish to keep (sellotape and newspaper) and taking your time with lots of thin coats you'll have a much better screen for your needs. Plus the black surround will do your PQ no end of good. (Obviously don't move it until its very dry)

    I did this a couple of years ago when I when from CRT to DLP. My manual pull down hasn't cracked or rubbed or smeared or anything. The whole job took a day and cost about £20.
     

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