1. Join Now

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

Lens chromatic abberation

Discussion in 'Projectors, Screens & Video Processors' started by gandley, May 22, 2005.

  1. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    from the off well happy with the PJ except in the process of considering upgrading to the 300E spec and having a few demoes here and abroad, i have noticed that the purple fringing on my optics seems to be a more excessive than the other models i have seen.

    When i enter the focus pattern and use the large pattern to set focus right across the screen the purple fringing is so very noticable that the white blocks are all joined by purple lines so you get a purple and white square, if i defocus the lense the purple turns to a light green colour.

    Now on the 300e,s i have seen one didnt show up a single bit of purple(in fact the focus was pin sharp) another showed up a little and on another 300extra-H again the fringing was barely noticable if any.

    My concern is if i upgrade to the 300E will my optics still show as much abberation(which i guess the answer is yes) or will sim2 take a good look at this and see that its a bit too much(as i think it is to be honest from from what i have seen elsewhere).

    Also be interested if other peeps see the same with there sims.
     
  2. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    31 views and not a single comment.

    Try, no i dont see that with my sim2 or yeah i see that but its no bigy etc etc. :D
     
  3. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,420
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,086
    I'm sure Jeff or Alan will be along any time now to to help you with this. :)

    Gary.
     
  4. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    have you ever seen this with a sim2 Gary? if you can recall that is
     
  5. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,420
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,086
    No, never.

    Sims normaly have very good lenses on their machines so I'm surprised you are getting this. I did se somthing on my HT1000 with a Toshiba DVD player though - it only did it on PAL outputs though. Green tint on the left, and purple to the right, as if the green had shifted left. As soon as I switched back to NTSC the misalignment went away, and it didn't do it with any other player.

    Gary,
     
  6. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    Yes that is exactly what im seeing, Purple to the right on accurate focus, but if i defocus slightly i get the green tint to the left (saying that green is there at normal focus but not quite as noticable.)

    But i havent seen this on the 300e`s i have demoed so i thought things had just got better. Until that is i saw a demo with a 300xtra-H and noticed that there was zero abberation present which kinda made me think what the fudge.....
     
  7. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,420
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,086
    Does it do it with other sources, such as sky or freeview? If it doesn't, then it's not the lens. The DVD player I had the problem with was a Toshiba SD520e btw..

    Gary.
     
  8. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    well its doing it with the inbuilt sim2 test patternes, and its also the sim2 menus that look the worst for it.... It is not source dependent as no matter what im watching if i enter a sim2 control menu its there.
    Its also been present with all the various make dvd players i have had.

    the Pattern to focus the projector realy shows it up and its here that i can see the colour shift between green and purple.
     
  9. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,420
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,086
    Hmm, that does sound like the lens or at least, something optical maybe. Unusual for a Sim2 as well. Jeff or Alan will probably be along soon and help sort this out for you.

    Gary.
     
  10. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    I hope so as i dont really wanna pay to upgrade it knowing that this kinda (im not going to say fault) makes it look a little ropey (maybe fault was a better term)

    Thats for the help though Gary, grateful for the input
     
  11. RTFM

    RTFM
    Active Member

    Joined:
    Mar 6, 2003
    Messages:
    1,014
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    38
    Location:
    Horsham, West Sussex
    Ratings:
    +17
    Gandley

    Chromatic Abberation (CA) in optical systems is very common.
    In a former life as a 1st Assistant Cameraman (Focus Puller) working on feature films, I would spend a week testing the Panavision lenses by shooting tests of focus charts at various distances and also projecting test patterns through these camera lenses by fitting them to a projector. All lenses displayed some CA to some extent or another, depending how big the image was and CA was more evident at the edges than in the middle as you would expect. I would obviously choose the lenses that had the least CA.

    My point is, if you cannot see any CA or other artefacts from your viewing position then don't be concerned. Sure, if you go up to the screen with any projector you will start to see CA, picture structure, dithering etc.
    If you are seeing CA from where you sit then maybe the projector was handled roughly by the courier and some misalignment in the optical system has occurred. If that's the case, take it to your dealer for him to assess.

    Jeff
     
  12. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    No i can see it from my seating position, and on things like film credits if they are white on a black background.
    My dealer will no doubt just send it to sim2 and as i soon want to do the DC3 upgrade i was hoping they could take a look at this at the same time(and do a realign if thats what causes this issue)

    + the fact that my dealer is way up country.
     
  13. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    Ok swaped out dvd player and i now cant see the aberation in the picture so that was down to the dvd player which was a bit weird but then it was a toshiba sd 9500 and it has been seen with other toshibas.

    So looks like it might well be within spec, just me been a fussy git, as it can only been seen now on sim2 test patterns.
     
  14. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,420
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,086
    Sounds like it might be a Toshiba 'thing' as my 520e did exactly the same thing. I'm surprised you can still see it with the Sims own test patterns though.

    What player are you using now?

    Gary.
     
  15. gandley

    gandley
    Well-known Member

    Joined:
    Aug 31, 2003
    Messages:
    5,024
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    106
    Location:
    Paradise Lost
    Ratings:
    +269
    I have a denon A1XV on loan.
     

Share This Page

Loading...