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I recently returned to using the HMC FL-D filter and have been trying out different color settings and got to wondering how others set their color settings. I'm not quite ready to spend the $150-200 needed to purchase the Smart (store) or Smart (intro) hardware & software either. So I'll try to outline how I set color....


First, using the HTPC I display a B&W photo for wallpaper. I have read previously that the human eye is much more sensitive to changes in B&W than color. I then adjust the colors to make the image as B&W as possible using the RGB controls.


Next, I fire up AVIA and goto color decoder check. IMHO this test is about as reliable as my first car using the supplied filters but at least it gives me an idea if I am in the right ballpark.


Finally, I go on to check my brightness & contrast settings and do it all over again to adjust for any changes.


As far as gamma adjustments and color temp I tend to leave those at normal on the PJ side.
 

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Don't tell anybody, but I do it the old fashioned way: guesswork.


I use a black-and-white picture, and try to get all the grey tones to look neutral. Any trace of color and it's back to the drawing board. (And don't forget the ancient wisdom: write down your original settings or you'll never be able to get them back again. Also, in the immortal words of my college radio station chief engineer: Don't fool with any knobs you're not familiar with. [You can imagine the sophomoric guffaw that one prompted.])


If you succeed in this, and then switch over to color source material, and that doesn't satisfy you, you may have to tweak further. Only problem, of course, is that your b&w will then go to hell. Greyscale bars will help, too.


Naturally, if your projector can't produce a relatively even greyscale, there will be traces of color at certain shades of grey no matter what you do (since many of these units don't permit separate control of bias and gain). My Piano, for example, while very, very good in this respect, seems to run a little colder (bluer) at the dark end, which no amount of monkeying with the user r, g, and b controls will eliminate. This is so subtle with my lamp (and I assume it varies somewhat from bulb to bulb) that it's barely noticeable in b&w, and dark scenes look ever-so-slightly bluer (cf., the fleshtones) than more brightly-lit ones.


If you don't like guesswork, there's always the scientific method (which involves ISF technicians, color analyzers, and money, money, money--how do you think they pay for those gadgets?). Frankly, while I'm not an expert, I wonder how accurately one can set an LCD or DLP with a color analyzer designed primarily for CRTs.


But of course then you'd be missing half the fun of trial and error, such as green skin-tones and orange hair. (It's amazing how much better Billy Bob Thornton looks as a Martian...)


And if all that didn't provide enough hours of enjoyment, consider the fact that as the bulb ages, its color characteristics will change. So just when you think you've got it exactly right...
 

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I am CRT person, but you could use the same idea.


First I set the G2, then I use a subtitle of some sort to find white.


Then I use nokias testpattern to set brightness and contrast.


It can not be called calibration, but better than nothing.
 

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I use a photocell from solar power science kit ($10) plus the Avia color filters and a digital multimeter which I already had. I used mid day sunlight as a reference and measured the current with each of the three filters in place. Then I put the sensor directly in front of the projector and adjusted the color to give the same ratios of currents. This is a cheap way to do it as you calibrate with sunlight. See below for a few variations and gotchas.


The results were somewhat surprising for my LT155.


Some history: The LT155 looked green-yellow out of the box and from reading the posts, interpreted this as too much blue and green. I got a FL-D filter and adjusted the color by eye. It looked much more dramatic but had too much purple.


Later after making the measurements with the photocell I realized that I had high red and green (= yellow) and insufficient blue. So I referenced filters with a curve matching my needed ratios and bought an 82B (blue not red like FL-D) and then the color balance settings are correct when flat. I have bumped up the drives to max to raise the available range.


Moral of the story: eyeballs make lousy color meters because they adapt too quickly to misbalanced lighting conditions.


More procedural details

I originally used voltage instead of current but realized that it wasn't linear with light intensity. If you match the daylight voltage when using the sensor in front of the projector then you cancel out some of the inaccuracies but it is better to use current. I have calibrated voltage versus current and can go back and forth but it requires a 3rd order polynomial fit to the log-log comparison. Even then there's no guarantee the calibration won't shift with temperature.


You will want to avoid light spill around the edges of the sensor which in my case required a bit of electrical tape (it is about 1x2" and 1/4" thick.


You can also measure the light of a nonwhite wall and compensate the color. Though to make this bright enough to stay near your calibration range you will likely need to move the projector to within a foot or so of your screen.


With this sensor I measure full on versus black contrast as 185. And now I'm having fun figuring out how the gamma varies with setting (Nat1 looks flattest across the range).
 

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Hi DRS,


Reference point is everything to start. Without a good reference to directly compare with, one will never know.


So you have a reference, try all the adjustments/conbinations. There is no easy way. When all is done and if it's still FAR from the reference, time for a change.


My reference: NEC XG85 and Sony G70 at their best looking, both DVD and HDTV.


When directly compare to my reference, I still enjoy my AE100.


Usage at 479 hours and counting...


regards,


Li On
 

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I also used the "reference" aproach. In my case I used the best display I had at hand that bieng my PC monitor. I set up the monitor for 6500k (not sure how close it really is but better than nothing). Then I try to come as close to matching the pc image with my Sony projector as possible and the results were outstanding..a lot better than using AVIA alone.

Regards
 
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