Does lens shift on ae700 affect picture quality

Discussion in 'Projectors, Screens & Video Processors' started by fallwood, Oct 13, 2004.

  1. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    Does using lens shift on the ae700 affect the picture quality at all. my mate got his 700 today and i went round to help set it up. After id installed all the latest graphics drivers and 1:1 pixel mapped it i notiiced that it didnt look anywhere near as sharp as my ae500, i have a 5'7" across screen with the projector ceiling mounted at a distance of about 9 foot, my mate has a 6"6" across screen with the projector at a distance of about 13'. The focus seems to be off from about halfway down to the bottom and in the top right corner of the screen, you can easily see this by dragging an icon around the desktop and watching it go in and out of focus, the projector is mounted in line with the top of the screen and then lens shift used to bring the image down. Would the increased screen size and distance plus use of lens shift affect the picture so dramaticaly.
     
  2. theritz

    theritz
    Active Member

    Joined:
    Aug 17, 2002
    Messages:
    2,455
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +27
    Sounds more like the screen isn't perpendicular - whatever about focus in the extreme corners, if the lack of focu is right across the screen from half way down, it sounds like the screen is "leaning away" at the bottom... did you try shooting it without lens shift ?


    s.
     
  3. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    The focus seems to be off towards the bottom but cannot be corrected, the bottom half is blurier than the top half even if focus is adjusted . The bottom of the screen is flat against the wall while the top is held off about 1" by the hanging brackets, bringing the bottom of the screen out to match the top has no effect on the focus, if picture is moved to the left with lens shift the top right corner becomes clearer as it gets closed to the center of the screen, same applies when the picture is moved up. I was also surprised to see that the lens shift does not keep the image perfectly straight and keystone still has to be used to correct the picture, i thought the whole point of lens shift was that you didnt have to use keystone correction.
     
  4. MikeK

    MikeK
    Well-known Member

    Joined:
    Oct 9, 2004
    Messages:
    2,231
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    83
    Ratings:
    +316
    Is the problem the same throughout the zoom range of the main lens?
     
  5. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    havent had a chance to do more tests as i had to go home for sleep, will be going round tonight for more testing to determine the problem. when i got home last night and switched on my projector the difference was enormous the pictures so sharp you could cut your eyes on it. How much sharpness would be lost due to the increased screen size and projector distance that my mates using (if any).
     
  6. Darwock

    Darwock
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I wonder about this... I imagine that everybody using an AE700 so far will have used the lens shift, as the default just doesn't look practical. If it needed additional keystoning it would surely have been mentioned elsewhere by now?
     
  7. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    Thats what i would have thought. This is an example of whats happening with the lens shift. The projector is set dead central with no lens shift at all, the image is perfectly aligned to the edges of the screen, if i then move the image up using lens shift you can see the bottom of the image get narrower the further it is moved up the screen surely the picture should maintain its geometry as its moved with the lens shift, then the image needs correcting with keystone defeating the object of the lens shift. I suspect a faulty lens or optic block as at its best the image is no where near as sharp as my 500.
     
  8. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    No, the focus seems to get better when the image is made larger, the smaller it is the worse the focus seems. Id have thought that it would get worse the larger you made the picture. Thinking about this , i have my projector on maximum image size and then i moved it towards the screen till the image matched my screen size so the projector is basicaly as close as it can be while attaining the screen size i require (5' 7" across at a distance of 9 feet, ceiling mounted with -2 keystone). Does the zoom effect the image sharpnes at all.
     
  9. theritz

    theritz
    Active Member

    Joined:
    Aug 17, 2002
    Messages:
    2,455
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +27
    If this is not an issue with screen placement, then maybe the unit is faulty ? I too would have thought that if this was a widespread problem it would have been reported before now - plenty of examples in folks hands at this stage.

    S.
     
  10. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    Can someone just clarify if its best to place the projector far away with minimum zoom or closer with maximum zoom, does it make a difference to the picture.
     
  11. MikeK

    MikeK
    Well-known Member

    Joined:
    Oct 9, 2004
    Messages:
    2,231
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    83
    Ratings:
    +316
    Or in the middle with medium zoom! :)

    Seriously though, all zoom lenses will have a sweetspot (ie a point in their focal length range at which they perform at their best), but for such a limited range as a projector's zoom range, then it should really be a pretty negligable difference.

    I would be inclined to agree with theRitz - if the problem is as easily visible as you say, and you've checked everything else, it could well be a faulty unit - if all production units were similarly afflicted, I'm sure this and other forums would be on fire with the issue by now.

    Where did you get it from - can you take it in and demonstrate the issue to the dealer?
     
  12. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    Thanks for the advice, will have another play with it when i go to my mates tonight and advise him of what youve said, i was hoping to make a decision on whether to upgade my 500 or not based on seeing his, guess ill just have to wait till he gets a properly working unit.
     
  13. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    Quick update. Went round to my mates tonight and the picture has improved considerably ,the blurring is gone and focus seems to be fairly even over the entire screen, lens shift also seems to be working correctly now. Its not been moved since last night so ive no idea why its improved so much (no we werent drunk) . Do these projectors settle in after a few days or is this just a weird unexplainable occurance , anyhow the bottom line is it seems to be fine now. Thanks for the suggestions and info.
     
  14. Tup

    Tup
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    So now how does it compare with your 500? Or do you need more time to tweak it?
     
  15. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    Blacks are definately better and vb is only noticable if you really really really look for it wheras on my 500 it can be seen quite easily on certain scenes, black levels and vb aside I wouldnt consider the general pq to be any better than the 500, its hard to compare as the unit is farther back than mine and the screen is a foot wider so it doesnt look as sharp or bright as my 500, space scenes and dark scenes definately look better but standard scenes look about the same to me. If black levels and vb are a big issue for you then yes its worth upgrading , personaly i think ill wait for d5 panels as ive only had my 500 for 3 months .
     
  16. theritz

    theritz
    Active Member

    Joined:
    Aug 17, 2002
    Messages:
    2,455
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +27
    Fallwood,

    That's got to be the weirdest thing I've come across here...... and that's sayng something !! :D If you can isolate the particular form of pixie-dust that provided the solution, you'll have a steady line of customers....... ;)


    S.
     
  17. bentleg

    bentleg
    Active Member

    Joined:
    Aug 16, 2004
    Messages:
    330
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Notts
    Ratings:
    +6
    Just make sure you don’t get any if that pixie-dust trapped in your lens :laugh:
     
  18. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    According to a few threads over at avs forums its not quite the black magic it appears to be. A few people have reported increases in picture quality after the projector has been used for a few days, I wonder if it could have been caused by condensation inside the machine that has now dried out.
     
  19. Darwock

    Darwock
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    The angle thing is pretty weird though, I don't see how condensation could affect the direction the lens shoots at.
     
  20. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    I think the lens shift problem was to do with the projector not being level (I know , Im an idiot) , just plonked it on the shelf and assumed it would be ok as the shelf is level and the image looked level on the screen, i suppose even the tiniest fraction out of level will create an effect when moving the lens shift up and down, didn't realise it was so critical. Does the condensation theory sound feasable as to why the pictures improved so much and could it have caused any damage to the internals.
     

Share This Page

Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice