Film-Tech Forum ARCHIVE: color meters

This is topic color meters in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Kyle Mitchell (Member # 8059) on 06-14-2014, 04:51 PM:

Which ones are approved by NEC and Christie? Anyone have any for sale?

Posted by Marco Giustini (Member # 4544) on 06-14-2014, 05:07 PM:

Unless Christie or NEC have developed an automatic calibration for their machines which I'm unaware of, there are no 'approved' colour metres.

Posted by Mark Gulbrandsen (Member # 72) on 06-14-2014, 05:51 PM:

It's not if a color meter is approved or not it's if it's designed to do the job you need and to what accuracy. The higher the accuracy the higher the cost. There are three primary meters in use today. I use a Minolta, there are also capable meters by USL and Photo Research. I also carry a Spectra screen brightness meter with at all times since I do not always carry the Minolta which is too expensive to leave bouncing around in the car all the time. Some ONLY measure color space and foot lamberts. The Minolta goes much further...

Occasionally used meters do come up for sale.

Photo Research

USL PC-100

Minolta CS-200

Posted by Marco Giustini (Member # 4544) on 06-15-2014, 04:24 AM:

I like the Jeti, very small and convenient to carry around

Posted by Steve Guttag (Member # 268) on 06-15-2014, 09:18 AM:

I use the USL for the bulk of cinemas...very convenient. By and large, it does the job just fine.

For screening rooms and Dolby 3D, I prefer the Photo Research. It is the gold-standard in the DCinema industry. Its accuracy is the best.

However, while it is great to have all of this test equipment that spits out numbers to plug in...they are near meaningless if you don't have them calibrated. Most color meters need to be re-calibrated once per year for their readings to be accurate.

Posted by Marco Giustini (Member # 4544) on 06-15-2014, 09:38 AM:

I'm not going to argue about the calibration but AFAIK colour meters won't drift like a Dolby Clock if you don't calibrate them! I'm not saying you shouldn't have them calibrated on a regular basis though.

Posted by Steve Guttag (Member # 268) on 06-15-2014, 12:12 PM:

Ask a manufacturer how long they should remain accurate. Have more than one meter and see how long they agree with each other.

Depending on the method of reading the color, they are more or less prone to drift too.

Posted by Mark Gulbrandsen (Member # 72) on 06-15-2014, 12:24 PM:

Steve is right. The sensors they use are very touchy, extremely sensitive and they do require frequent calibration. If you use it a lot or if it lives in your service vehicle then probably twice a year would be safe.

Mark

Posted by Bill Gabel (Member # 1105) on 06-15-2014, 02:03 PM:

We use the Photo Research PR-655 model at my location. For the main theatre and two DI rooms.

Posted by Harold Hallikainen (Member # 5405) on 06-15-2014, 05:51 PM:

Another consideration is the technology used to measure the color. I believe spectrometer-based instruments are more accurate than optical filter based instruments since the filter shape on the spectrometer instruments is defined by numbers in a table instead of layers on a lens. This is important with "spikey" sources like xenon. On calibration, it is unlikely that two instruments or an instrument and a source will drift the same. So, if the projector was calibrated with a recently calibrated instrument and later is still in tolerance, it probably is.

I'd like to again point out the USL LSS-100, which is permanently installed in the auditorium and, with the help of a test DCP, reports luinance, color, and SPL for each speaker.

Harold

Posted by Paul Mayer (Member # 355) on 06-15-2014, 05:51 PM:

The Photo Research Cinebrate spectroradiometer is what I carried with me during my Christie jobs here in NM and TX.

Posted by Amanda Mundin (Member # 3386) on 06-16-2014, 11:55 AM:

How much does the USL LSS-100 cost out of interest?

Posted by Clint Koch (Member # 1179) on 06-18-2014, 05:36 AM:

List price for the LSS-100 is $785.00 US