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AVIA calibration

Discussion in 'Home Cinema Buying & Building' started by G a f f e r, Apr 21, 2004.

  1. G a f f e r

    G a f f e r
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    After using the avia disc, I thought the picture was a tad too "lifeless" but persisted in using the settings it suggested because I thought it was 'meant' to look like that.

    My bro just borrowed my avia disc to set his optoma h30 up properly.
    Found that the contrast was way off and the whole image looked dull and washed out (too colourless).
    So he recalibrated it by eye and found that the cinema setting was the best (ie the built in one).

    So I went back to my flat and, sure enough, my AE500 projected a particularly dull and washed out image as before. Increasing the contrast didn't help. Ignoring the AVia entirely, howver, and using "dynamic" for daytime and "Cinema2" or "normal" for night time and the difference was stunning. MUCH more colourful, with flesh tones just right.

    Q: Am I not using the AVIA disc properly? I understand that for contrast, you should just about see BOTH dark moving bars against the white background, and for brightness you should see the right black bar but not the left. Can anyone confirm I'm doing it right?
    For colour and tint I adjust the levels until the blue squares don't blink any more. But these settings seem too dull...........:confused: What's Goin' on?
    Should I ditch the AVIA and buy DVE or stick with the preset settings (which at the mo look great)
    cheers for any help
     
  2. gizlaroc

    gizlaroc
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    Stick with whatever looks good for you, I dont think you can get it right on a digital to be honest.
    I think you would be better off doing it by eye, or calibrate it to D65 if you want to get it right using somthing like smart III.

    I always adjust contrast using fine detail patterns and when you start to see it bloom you know you have gone too far.
    I cant see how you can adjust brightness on a digital properly?? most digitals cant give you details below 10ire and the right hand black bar is 4 above and the left hand one is 2 above from memory isn't it ?? So it will looked washed out if you can see the right hand bar I owuld have thought.

    If you are happy with the picture that is all that matters really :)
     
  3. G a f f e r

    G a f f e r
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    Thanx gizlaroc. I'll retry with the left hand bar onbly.

    Problem is I could end up spending my life endlessly tweaking the AE500 (it's got loads of menu's) so I just want to get it right once and for all (for all film types).


    ((the fact that I'm a bit of a perfectionist (and that I read these forums :)) means that I don't know when to stop :D , it's taken me two months to force myself to stop looking for dp's/vb)
     
  4. buns

    buns
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    without being grayscale calibrated (D65) AVIA results are bound to vary. If you took a sanyo Z2 from the box with a basic avia calibration, the image is going to have blueish whites and red skin tones. If you set it by eye you may get a result that is technically not as good but actually gives a more pleasing picture. This is all because the greyscale tracking is off

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  5. Peter Parker

    Peter Parker
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    With Avia using the needle pulse tests, use the large moving black bars screen as the half white/half black one is harder to use due to the bright white causing your iris to open too much and you can't see the black bars too well.

    Adjust the brightness untill the left hand black bar of the two just dissapears, then bring the brightness back up until it reappears. The first black bar is 1 ire above black (whatever black is set to) and the second black bar is 2ire.

    Don't forget that NTSC and PAL encode black at diffetrent levels, so setting for one won't be the same for the other. Having a 'below black', 0ire or similar setting for NTSC helps to make them the same though IIRC.

    This is an interesting read from Guy Kuo who works for Ovation and had something to do with Avia:

    http://www.avsforum.com/avs-vb/showthread.php?s=&postid=3307309&highlight=1ire#post3307309

    HTH

    Gary.
     
  6. G a f f e r

    G a f f e r
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    Thanx gary and everyone.
    I'm gonna read that extensive post very slowly and try to figure out what it all means :D

    thanx again
     
  7. Peter Parker

    Peter Parker
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    I know what you mean - it's kinda like watching The matrix for the first time. :)

    I kinda getthe impression that if you use HTPC, you only have to set the white and black levels once, and whatever format you play (PAL or NTSC) will be correct.

    Anyone know for sure? I may post the question over at the htpc forum. :)

    Gary.
     
  8. G a f f e r

    G a f f e r
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    Right
    recalibrated with different test patterns and have ended up with the NTSC calibration being very similar but the PAL calibration being vastly different (up to 50% out c.f. my first attempt last month).

    What happened to my eyeballs last month?
    There is a world of difference and the picture now looks amazing, animation looks especially crisp and colourful.

    the patterns I used this time were (all from video test patterns):

    white level = Needle Pulses
    black level = Black Bars
    Sharpness = sharpness
    saturation & hue = first using Split Colour Bars alone, then double checking with blue bars, red bars and green bars (using those filters) seperately

    colour temp set at zero, picture set to normal

    I found that with PAL, the contrast had to be increased by 7, colour increased by 4, and tint reduced by 5.

    PS can anyone enlighten me as to the GAMMA test. I can't figure out what they're talking about as the background is stripy not grey. Defocusing my eyes doesn't really help.......how do you set the gamma???
     
  9. G a f f e r

    G a f f e r
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    scratch that....just bought a flourescent day filter and recalibrated. Settings are similar for both ntsc and pal output from player now (with ntsc requiring slightly more tint and saturtion values).
    Picture looks fecking MENTAL now. Demo'd on my bro's H30 has convinced him that he needs one too (it's a corrin flw a036 i think). Reduces the greenish tinge (more noticeable on h30) back to nromal TV levels (ie tinge gone)
    put in finding nemo and it looks like you can "reach into" the fish tank and pick out the characters. Awesome. Contrast and black deatail more improved (on th re-calibration, brightness had to go up a bit but looks like I'm staring at a 6 foot telly now). In fact, I'd even go as far as saying that (calibratied well) it can make a LCD look more like a DLP (but without the rainbows).
    Tried with normal (non-cgi) film and again, picture looks more DLP like wrt contrast and black detail :D
    All this for a measly £7.50 for the filter.......


    PS oddly though, whereas before the picture was bareable in subdued light conditions, it looks pants now if I try to watch in daytime compared with before. Doesn't matter too much as all my serious watching goes on at night. Just thought it a bit odd...
     
  10. jasonjbj

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    flourescent day filter
    WHERE DID U GET THIS FROM/?
    WHATS YOUR SETTINGS NOW??
    THANKS
    JASON
     
  11. Peter Parker

    Peter Parker
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    Gaffer - the filter does drop light level, so maybe that's why it's not as watchable during the day?

    Gary.
     
  12. G a f f e r

    G a f f e r
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    Gary - very good point. Should've thought of that :D

    jasonjb - go to your nearest Jessops high street shop.
    The Corin A036 filter costs £7.50 alone. Ive blutacked it onto the shroud, leaving a gap so that hot air can escape and you get a circulation. This filter is plastic. Don't buy the lens adapter that goes with it though (extra expense and no real need). If you do want a snug fit, go for the multicoated Hoya flourescent day filter. This is made of glass. The size you need is 52mm i think (but check you can return it if wrong size- i think 52mm is the ae300/500 size). As it's a pre-made lens filter it should fit snugly with less need for air circulation as it won't melt. (the corin filter is really just a square bit of lightly coloured plastic). The Hoya filter has to be ordered from them and costs £18.99 i think.

    Remember, let the projector warm up for a bit first (i leave it 15 min or so) before recalibrating. I don't know if this has any effect but it's what AVIA recommend (doesn't hurt either :) ). Recalibrating for me resulted in mainly putting the brightness up a tad and deiciding wether or not to alter the colour temp to more blue (which I didn't in the end).

    Keep the reciept. Jessops said if I wasn't happy, I could return the filter (not that I'm going to)



    Settings off the top of my head (for PAL discs):
    Contrast -4
    Brightness +1
    Colour -12 (-10 if ntsc)
    Tint +1 (+2 if ntsc)
    Sharpness -1 (used to be -2/-3 without filter)

    These settings should be a guide as yours will obviously be different in your surroundings. The settings are when viewing at night (+blackouts ie as dark as possible for me)

    I've got memory1 for PAL discs/output from dvd, memory2 for NTSC discs, and memory3 for console/gaming
     
  13. G a f f e r

    G a f f e r
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    Sorry to bang on about this (i'm having a dumb&Dumber day), but gizraloc & Buns - how do I calibrate the grayscale?
    are there patterns on the avia disc that do this?
    I have since found that (compared to a well set up tv), the filter reduces green favourably but a tiny bit too much, so I've increased green brightness a tad to make it seem more natural. Overall, this still results in less green than before and a stunning picture.
    Just thought I could improve things further? (it's that damn 'tweaking' gene of mine you know :( )

    oh and do you do the greyscale calibration before the avia one or after?

    thanx
     
  14. Peter Parker

    Peter Parker
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    Idealy for grey scale calibration, you'll need a colourimiter that can measure the colours as the eye sees them. You need to adjust the individual RGB brightness levels for the lower IRE ranges, and the individual RGB contrast for the higher IREs.

    You can adjust the basic brightness and contrast first, then adjust the colours, then recheck the B and C again.

    It can be done by eye to a degree if you've done this before (apparently Alan Roser, MD for Sim2 did this, much toe everyones amazement), but it'll take a lot of trial and error to get something accurate. :)

    The colour filters supplied with Avia may have a use here - I've not used them myself, but maybe someone can shed some light on this.

    An affordable calibration tool such as SMART III form the USA costs around £200 inc vat and postage, and is quite useful, but is time consuming and doesn't see light in the same way as the human eye. You can balance the RGBs, but they won't necessarily end up as D65 which is the colour temp of film you aim for.

    Colorfacts is the tool to have, and apparently Milori will be producing a low cost tool to that effect sometime in the near future - I read this on the US crt forum, but don't know if it's going to be available for digital pjs.

    Gary.
     
  15. buns

    buns
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    Sorry to have missed this Gaffer, im moving away from projection so dont spend as long in here.

    I second everything Gary says about greyscale. Colorfacts is a fantastic system and I'll add that you can hire it from millori directly at probably £250 a month inc postage back and forth.

    all the best

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  16. G a f f e r

    G a f f e r
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    THANX for all your help guys, I can set the panny up properly now :smashin: .
    I'll try to do it by eye until I can save up enough to use the colofacts.

    thanx again
     
  17. RTFM

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    Gaffer74,

    You'd be surprised how sensitive the eye is to the colour of grey.
    When you put up the Avia 10 IRE grey scale bars it's very easy to see any variation in the colour of grey at the various IRE levels.
    You can soon see whether there's too much red, green, or blue at a particular brightness level.
    With a bit of practice you can get the grey scale to look pretty even across the range.
    If you make a pig's ear of it you can always go back to the factory defaults and start again.

    Regards

    Jeff :rtfm: :D
     
  18. G a f f e r

    G a f f e r
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    cheers rtfm
    will try tonight (first need to update the dvd player firmware and see if i can use 720p via the component, in which case, I'll need to start over again anyway)
     

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