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Discussion Starter #1
As Mflaster reported in this thread: http://www.avsforum.com/ubb/Forum10/HTML/008093.html

he has corrected the green solor shift caused by the "tearing" fix of revision "L" for all Davis 650 and clones.

I just installed his new software and *viola* - color is back to normal!

What a great acheivement for us 650 (clone) owners and this should also mean that the Davis 450 and clones should be able to be "tweaked" to perfection as well.

Ahh, an XGA DLP with zoom, 6000 hour bulb capability, low rainbow and (now) decent colors: I don't feel so bad about missing out on the LT150 train!


THANK YOU MIKE!


Robert


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Robert Clark

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Its great news for the 650 owners who now have great color and no tearing but I am keen to jump on the bandwagon for the DL450 tune up...


Is this tune up performed on a projector by projector basis to fine tune the performance of each fingerprinted projector or is this a blanket adjustment that takes fixed values for the DL450 (primarily a business projector) and adjusts the gamma to a more HT friendly setting and can therefore be a one update for all...


What I am trying to say is... Is this something I may have to send my PJ away to have done to it or am I likely to be able to do this myself without specialist equipment ???


Also how much (I realize quantitive measurements of these things are near impossible) does this improve the (already good) image ??


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Discussion Starter #3
Phat,


If you're speaking of Mike's fix, then all you need is the upgrade cable from Davis. I'm sure Mike can help you (or adapt it for you) to alter it in any way you like.


If you're speaking of Thumper's fix for the 650, you'll have to send it to him...


Robert


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Robert Clark

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This is really great news for Davis DLP owners. updating the gamma table is really the last step I would like to take to maximize my DL450s performance.


Like Mike, I have also recently had my Davis Thumperized and so I think a full calibration process would need to be done to find the optimal gamma table for a custom projector like mine. The most important part of this process has now been solved. it is now possible to rent or buy the appropriate equipment to determine the proper gamma curve for you projector, but if you can not update the table in the projector this knowledge is of no use. So it is just a matter of time before Davis owners can take advantage of the kind of gamma calibrations that have been available for other digital projectors.


Thanks again Mike!
 

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Quote:
Originally posted by Robert Clark:
I just installed his new software and *voila* - color is back to normal!
That's great! I'm actually a little surprised, to be honest. You see, I've figured out how to extract the gamma curves, and how to modify them and replace them, but I haven't really been able to figure out what to replace them *with*. I tried a bunch of mathematics to try to push the colors in one direction or another, but unless you're exact, it ends up looking pretty bad. So, for Robert, I just took the gamma table from 'K' (with his color setting of choice - "True Colors") and put it in the 'L' software. I also left L's "True Colors" in a different color map so that he could swap back and forth and compare them. I verified that K's color map had much more blue and red than L's, but it was late, and my setup was calibrated for a different color map, so I had no idea if it would look good.


The reason I'm surprised is - if the exact same color ramp from 'k' works fine in 'l' - WHY DID THEY CHANGE IT??? I had assumed that by doubling the speed of the color wheel for 'l', for some reason they needed new color ramps. But if 'k's map works fine...


But just to be clear, this does *not* mean I'm prepared to calibrate projectors. As Jim points out, the *capabilities* now exist for modifying the Davis' gamma tables, but so far I'm *not* the person to figure out what they should be modified to. Heck, I couldn't figure out what to do to correct a major green shift (other than use a completely different table). I'm currently trying to resolve that through partnerships with people that know something... http://www.avsforum.com/ubb/smile.gif


One thing I was thinking about doing. These gamma ramps currently start putting out some light at about 2.5% IRE. Unless you're using a DVD player that renormalizes the signal to 0% IRE, that ramp should really still be 0 at 7.5% IRE as far as I know. *That's* something I think I can do. I think it should make the blacks much crisper, but who knows.


Mike



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Quote:
Originally posted by Phat Phreddy:
Is this tune up performed on a projector by projector basis to fine tune the performance of each fingerprinted projector or is this a blanket adjustment that takes fixed values for the DL450 (primarily a business projector) and adjusts the gamma to a more HT friendly setting and can therefore be a one update for all...
Well, right now, it's not performed at all!


For revision 'L' for the 650's, I think clearly there was a mistake made. It's easy enough to correct that mistake by taking the gamma ramps from 'k'.


Really, though, what people want (especially people like me and Jim that have had our projectors Thumperized) is an individual calibration. I'm hoping that what I've done is eventually a piece in that.


Mike



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Quote:
Originally posted by mflaster:
Really, though, what people want (especially people like me and Jim that have had our projectors Thumperized) is an individual calibration. I'm hoping that what I've done is eventually a piece in that.
Mike, I think it will turn out to be the most important piece, because it was the part that no one thought could be done http://www.avsforum.com/ubb/smile.gif


The exact thing we need now is a calibration routine like Mark has put in Dilard. In fact, if Mike would be willing to share his code so Mark can create a Davis capable Dilard (the name doesn't make sense in this case) we would only need to rent a photometer like the one available through AVS to be able to calibrate our projectors right in our own theaters. That may be a little ways off, but we Davis owners should try to convince Mark that there are a lot of potential Dilard sales out there from Davis owners http://www.avsforum.com/ubb/smile.gif
 

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Mike are you or anyone aware if the older Davis (power beam ) can be adjusted in anyway or the firmware accessed. I know they are getting long in the tooth but the SVGA DLP still puts out a fine picture and I know that more people have them than let on http://www.avsforum.com/ubb/smile.gif . There is a firm ware version in the OS menu but I have never seen an upgrade at all. The PB6 was also capable of being controlled by commands via the rs232 port.
 

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Any chance of fixing the scaing on these things to accept

720P or 1080I.


I think we would really have something if this could be done.


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Discussion Starter #11
Quote:
Originally posted by Alan Gouger:
Any chance of fixing the scaing on these things to accept

720P or 1080I.


I think we would really have something if this could be done.

Agreed. I have never tried as I have no HDTV hardware of any kind. I remember vaguely someone successfully using a Davis 650 clone with either 1080i or 780p but I could be wrong...



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Robert Clark

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Quote:
Originally posted by Alan Gouger:
Any chance of fixing the scaing on these things to accept

720P or 1080I.
Unfortunately, I think you're well outside of my capabilities with this. My plan would be to just get some HTPC card that can output 768P - I think the Hipix does that. Then you should be fine with any XGA DLP. Or is this wrong?


Mike



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Quote:
Originally posted by JohnMP:
Mike are you or anyone aware if the older Davis (power beam ) can be adjusted in anyway or the firmware accessed. I know they are getting long in the tooth but the SVGA DLP still puts out a fine picture and I know that more people have them than let on http://www.avsforum.com/ubb/smile.gif . There is a firm ware version in the OS menu but I have never seen an upgrade at all. The PB6 was also capable of being controlled by commands via the rs232 port.
I'm not sure what projector you're referring to, but if you have firmware for it, and you have the programming cable that can load new firmware, then I would bet yes, without really knowing.


Mike




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