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Discussion Starter · #1 ·
Some of us over in the RP forum have been working on getting the most performance out of HD-2 DLP based RP.


In this endeavor we have engaged the help of the Milori ColorFacts. Since this sort of effort is usually associated with higher end displays I thought I would share the results of an experiment with this forum.


Bill Cushman, reviewer for Widescreen Review, was kind enough to lend his expertise and GretagMacbeth LightSpex Spectroradiometer and Philips Color Analyzer. The idea was to use this equipment to verify the accuracy of the Optimagary Sensor included with CF.


Interestingly Bill was skeptical of the CF sensor and called me several times in the days leading up to the test, preparing me for the results. That proved to be unnecessary as the CF sensor measured almost identically to the Philips!


The LightSpex showed some error in the readings of the color coordinates, so we entered a new White Point Target in CF and recalibrated. The excellent results without this correction were improved upon.


I know there is a lot of interest in CF here on the forum, so I wanted to share this.


Ken
 

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Ken,


That is great to hear!


How did it respond in the low light readings. There was talk of some discontinuity or non-linearity in that region.


For us FP users it isn't that big of a deal since we can always move the color facts meter closer to the projector, but for the RP people it is more of an issue since the closest they can get is at the screen surface. Next time he comes over make sure to do a comparison of On/Off contrast ratios as reported by his Philip's meter and your CF analyzer


Anyway, I am glad to hear of this important verification. Colorfacts software has always been impressive. I am glad to hear the meter is holding it's own as well.


-Mr. Wigggles
 

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Discussion Starter · #3 ·
Yeah, I was pretty happy with the results.


The Optimagery starts to get flaky just south of 20 IRE and is not much help at all below 10 - at least on the Samsung HLM507W DLP. Thats with color. It seems to do much better with luminance readings. (?)


But, since a straight line is all you can do with gain and offsets getting 20-30 and above perfect seems to work great.


Here's a link to the whole thread for those interested:

ColorFacts thread in RP forum...


We didn't have too much time last night, but we plan to do more tests when my set gets here. We'll definitely do your test Mr. Wiggles. Hopefully you will be there anyway.


Ken
 

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Ken,


Give me a time and date. Work is much less hectic at the moment so I should be able to make it.


-Mr. Wigggles
 

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Hi Ken,


Excellent observation regarding the luminance/color accuracy at low light levels. The luminance does read lower than the color due to a single dedicated "luminance only" photodetector contained in the sensor. The other photodetectors do have an issue at low light levels, and it is something that we were unfortunately unable to address during the development phase without introducing other issues.


The dedicated luminance channel helps with taking contrast ratio readings and/or setting the black level, something that neither of our (fairly expensive) spectroradiometers can do, as they stop seeing anything at all below a certain luminance level.


Thanks for writing up your test. Will we be seeing this in a future issue of Widescreen Review? :D
 

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Mark,


Do you use the monochromatic photodetector for the on/off contrast measurements?


And I'm in agreement with your assement that other meters struggle at low light levels. I'm not sure if the LightSpeX falls into that category but I know the Phillips often has trouble reading "low" values.


Once again congradulations. Cushman is a tough guy to please and to have him happy with it at this point is saying something. You might not want him doing a full review because he probably WILL find something wrong with it. He's very thurough and will put it up against very tough standards.


Now if my MasterBrator name had only won the naming contest...


-Mr. Wigggles
 

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Hi Mr. Wiggles,


Sorry for missing your question here. Sometimes these threads just zip right by, and it takes a while before I read back that far. Anyway, the contrast ratio reading from ColorFacts uses all of the sensors.


Regarding the LightSpex, yes, it also has difficulty at low light levels, and we can't even use that instrument as a reference for the contrast ratio checks.


Everyone who read the "Naming ColorFacts" thread knows who the REAL winner was! MasterBrator was the unanimous crowd (and our) favorite!
 

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very awesome post.


colorfacts has been sitting in its box for the last couple of days. I think I might (cough, cough) be feeling a bit ill starting tomorrow morning - maybe I'll be well enough to get a head start on the calibration planned for this weekend.


agree that it would be great to see a full write up in widescreen review.


this should be an interesting weekend.

Mark - just wondering, is there a colorfacts user site active or under construction?

-jeff
 

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colorfacts has been sitting in its box for the last couple of days. I think I might (cough, cough) be feeling a bit ill starting tomorrow morning - maybe .

.....................................


You mean you DON'T calibrate everyday ??

My box say's "use frequently, everything shifted last night" :)
 

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Quote:
Originally posted by Mark Hunter


Everyone who read the "Naming ColorFacts" thread knows who the REAL winner was! MasterBrator was the unanimous crowd (and our) favorite!
For those who weren't around during the naming contest, here is the thread. One of the funniest you'll read within AVS :)


And you may not be aware, but there's an easter egg within ColorFacts too !


Maybe we should start a highscore competition ... lol


Cheers :)


Russ
 

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Things really started cracking me up on Page 13 , after Wiggles opened the flood gates.


Sorry to get off-topic myself. Just reminiscing...
 

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ld -

I will be putting my trusty ol' up-1100 & isco thru their paces. I have couple of filters around that will be thrown into the mix as well. when I start looking into a new pj sometime next year, I imagine that a laptop and Optimagery will help to identify the major contendors.

Quote:
Originally posted by JimmyR
You mean you DON'T calibrate everyday ??
its a good thing that MasterBrator did not win the name game.
 

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Help?


Seems like my colorfacts is somewhat confused. It is recognizing the meter as an ‘ocli micropac spectroradiometer’.


I would really have no problem with receiving a spectroradiometer, but somehow I don’t think that I did. Any suggestions? When I first connected to the meter, it worked ok and I was able to take measurements, but now I am not having much luck.


is there a colorfacts user site active or under construction?


Guess I have to go back to watching the Bears until I can get this figured out (talk about a bummer.)

-jeff
 

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Jeff,


Do you have any serial devices connected? If so, try unplugging them.


If your sensor isn't being "autodetected" correctly, click Edit | Options and pick the Communications tab and select the meter directly instead of "Autodetect".


Jimmy - We only work 16/7 each, but stagger the schedules so it looks like 24/7 :D
 

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Mark,

Thanks for the reply. I did have a serial device connected, but unplugging it did not work. I tried earlier today to select the meter directly, but received an error message.


I was going to try to install the sensor on my laptop, but don’t see the icon for transferring the license in the program files/colorfacts folder. I know that the usb ports on my htpc work, I tested with a mouse.


I sent support and alyssia an email with more details.


-jeff
 

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I still want a dongle for colorfacts which will let me calibrate component signals. Give it YPbPr and let it do the same thing - individual color levels, see if a 7IRE signal is putting out the right voltage, etc...


That way I could use colorfacts to do my entire chain of components. Whipping out the osc. to do this is just a pain.


(hint hint ;-)


-Jon
 

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And a little outboard pattern/color generator (inexpensive) would be nice too.


Plenty of room in the box. Quadruple hint :) Make it that funny shade "blue"
 
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