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Z2 Gain, Bias and Gamma - Help!

Discussion in 'Projectors, Screens & Video Processors' started by Wilster, Dec 4, 2003.

  1. Wilster

    Wilster
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    Hi folks

    Having cracked the 1:1 DVI on HCPC problem, I am now moving on to colour settings for my Sanyo Z2. I have read up on AVSForum about the service menu settings, but I think it would be much easier to adjust things to my liking if I really understood what each of these terms mean. So if some knowledgeable person could step in and explain what these things are, and what they do, I would be very happy!
    To see if Im going in the right direction, to remove the 'red push' in dark scenes, I should increase the gain (to make the light scenes 'redder' too) and decrease the bias (to decrease general red levels). Is this right?
     
  2. buns

    buns
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    i have played with a couple of devices using colorfacts which actually tells me exactly the changes that I have made..... i strongly recommend that you leave things alone unless you have hardware to measure, it is very easy to get things totally screwed

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  3. Wilster

    Wilster
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    Ive got a copy of the original settings, Im not scared of playing Already have in fact, managed to make some things better and others worse. A point of reference would be good I guess :)
    Question: How much does such kit cost, and how much would it cost to get an expect in to calibrate it all?
     
  4. Gary Lightfoot

    Gary Lightfoot
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    A copy of Avia would be useful - it has grey 'ire' settings so that you can see if adjusting the colours has altered the colour temp anywhere along the ire range. 0ire is black, and 100ire is white, so you can tell which way you're going. Avia costs around £25 form a chap on these very forums. He can be found in the bargain fotum I think.

    There's a product called SMART III which will allow you to do all those adjustments with some accuracy using a light meter and colour filters, but you have to get from the States. It works out arround £200 all in. Colorfacts is another product (Buns has it) but is somewhat more expensive. I don't know how much the rates are for calibration, but Gordon of Convergent may be able to give you an idea.

    HTH

    Gary
     
  5. buns

    buns
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    i only warn becausem even using avia...... i got things on my monitor to look pretty good..... but it ended up screwing other things up...... although i thought it was reasonably ok, the contrast actually was alot worse and i had managed to crush whites and (the word eludes me) the blacks...... this didnt bother me until i did it right and noticed how horrendous it actually was.

    the alternativem hardware wisem is to rent. As far as i knowm both smart and colorfacts are now available for rent for a reasonably good fee.

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  6. Wilster

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    Have just noticed the PJ settings thread is much longer than when I last read it... am working my way through it now :) Thanks for the advice, and I dont suppose either of you want to come over to Plaistow and practice calibrating a z2? hehe

    Strangely the red push has gone of its own accord, cant for the life of me figure out why. Have also noticed that many DVDs have an odd colour balance anyway, so no use as a reference for correct colours. Odd.
     
  7. Gary Lightfoot

    Gary Lightfoot
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    I wonder if that's down to the hours on the bulb? Lamps don't supply an equal amount of each colour, which is a filter and calibration can help a great deal. As the lamp ages, the amounts of each colour it emits gradualy changes too, along with the light output..

    Gary.
     
  8. Kramer

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    Doubtful he's accumulated enough hours given the length of time the Z2's been available.

    Now, if it was Calibos............................

    :D
     
  9. Wilster

    Wilster
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    Only about 20 Hrs so far (got the PJ on monday). Havent tried checking on the PJ yet though. Putting up some lightstop blinds from John Lewis today so I can watch during the daylight hours. This PJ is the best thing Ive bought in a long long time, even my wife has been out buying DVDs for it!
     
  10. buns

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    I have a few mins...... seems that the way you adjust is to get both an 80% and 30% gray field with the colors balanced.......ie so that they dont have any tinge of blue red or green present. I think you fiddle the gain for the low IRE and the bias for the high IRE. One further problem i can see by using your eye...... avs has reported menu 1-6 as being the gains and biases, but the service menu spreadsheet over there points to 1-3 being something else which has knock on effects later in the menu while 4-10 are the settings you actually wanted.

    I am going to be doing a proper calibration with hardware by the end of this week. I will document it fully and will document the whole thing and show what exactly what seems to do. I will have it available for anyone wanting it as a guideline perhaps. I dont know it will do any good, but at least maybe it will clarify how things work.

    all the best

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  11. rob@rar.org.uk

    rob@rar.org.uk
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    Thanks for that ad, looking forward to your report.

    Regards

    Rob
     
  12. buns

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    If anyone has anything specific they want trying (using the dvi input) let me know....... I'll fire through contrasts and color tracking for the color temps, contrast/brightness for the lamp/grayscale/iris....... calibrate via NTSC then fiddle pal via the pc.

    Anything else?

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