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Is a CRT monitor spectrum same as CRT front projector spectrum?

Discussion in 'Projectors, Screens & Video Processors' started by Gary Lightfoot, Sep 15, 2005.

  1. Gary Lightfoot

    Gary Lightfoot
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    The reason I ask is because PaulB has loaned me his SpyderTV calibration tool for testing. It's a colorimiter very similar to one used in Colorfacts, and I've been testing it alongside my own Colorfacts colorimeter. It's designed for direct view displays but with other software can be used for projectors.

    I used it to set my monitor to 6500K (I don't think there was a D65 option on thos particular software), and then measured it with Colorfacts.

    The CF Trichromat-1 sees all displays (direct or projected) accurately as far as I know (there was a glitch with fresnel lenses in the past though IIRC), so I took some readings from my PCs CRT monitor and compared it to the TR-1. The readings are so close that I feel the SpyderTV can be used for calibration to within 3% accuracy of D65 - ideal for home use IMHO.

    The only unknown is whether or not a front projected CRT produces a similar spectrum to a CRT direct view tv or monitor. I don't see why not but thought I'd ask and at the same time see what interest there is so I can post the info necessary for you to get it working for your own pj, along with some comparative data so you can see how close it was to Colorfacts so you can make your own mind up.

    Gary.
     
  2. theritz

    theritz
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    Don't have an answer for your question, Gary, but if you could give the SpyderTV a test run at calibrating your front projection setup and tell us how it performs, I'd be very interested in reading your findings - I've seen these online but would like to read some "real world" findings about it's use for front projection before buying one.................


    Thanks,

    Sean.
     
  3. Gary Lightfoot

    Gary Lightfoot
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    Hi Sean,

    I tried it on my DLP and it's pretty close using the alternative software, but I whilts reading through one of Pauls avs links I found there is a way to get the x, y, Y co-ords from the SpyderTV software itself, and I believe an avs member had good results with that on his DLP. There is an Excel spreadsheet that helps to model the readings into info that helps you to make adjustments (i.e increase red, or blue), and that is all we need really.

    I'll try out the SpyderTV software on Saturday all going well, and once I've got some overall conclusive results will report back. So far though, using the alternate software with CRT monitors is pretty much spot on and could be the same for CRT front projectors (you will need good contrast modulation though I would think for it to work well). As a last resort, I can put in my readings for D65 and make those co-ords the new target so it will in effect be pretty much D65. All the software does is translate the hardare readings into co-ordinates which can be different depending on the software.

    Gary.
     

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