Based on the calibration date you are using a CA-6X model probe.  The CA-6X was designed with a separate removable diffuser which may be attached to the suction cups located on the face of the probe.  The diffuser is used only for calibration of front projection television displays when the user wishes to calibrate with the probe oriented towards the projector lens.

The user should set the probe calibration to "FPTV" on the main panel of the software so that the correct calibration matrix is utilized when calibrating with the diffuser mounted to the probe.  The CA-6X is a fixed rate detector design and measures at approximately three measurements per second regardless of light level.  The probe only has detectors located on one side of the instrument, the large White eye which I believe you are referring to is simply the back side of the enclosure.

If you need to get a replacement diffuser for your CA-6X please contact us at the office anytime and we can assist you with getting a proper replacement for it.  The number at the office is 212-254-3541.



Regards,


Cliff
Progressive Labs

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Cliff

Typically CRT projectors do not have very high light output (depending on screen size).  Assuming your Dwin is no light cannon I believe that you calibrated the system correctly by measuring the light from the lens using the FPTV calibration in our software and the diffuser attached to the probe.  Measuring directly from the screen is possible from many of the newer digital projectors as they are significantly brighter.  This methodology provides a more accurate calibration as it takes the screen chromaticity shift from the material into acount which measuring from the lens does not allow for.

Measuring from the lens of a low light output projector has its advantages as you are able to locate the probe as close to the lens as  needed to increase the amount of light available to measure.  This generally improves the Black level readings which if measured from the screen would be inaccurate due to the extremely low light levels measured.  As long as the screen material being used is a Matte White screen with a gain of 1.3 or less you should get virtually identical measurements from the lens or the screen.  The only other caveat is that your room environment needs to be neutral in color so that no stray light is reflected onto the screen which will impart color shift.