I forgot, I wanted to publically thank Cliff for chiming in about the progressive labs/Ovation OptinONE. After doing quite a lot of hunting, and getting input from some big dog calibrators, his is looking very attractive to me. Add to that a deal at onecall and AviaPro to boot and.... I was further swayed his direction by a informative personal explanation to some specific questions direct to me.
I've used the SmartIII system with a very sensitive light meter. I found the results of aiming and distance to be profound, *drastically* affected by the clightest change in either. Taking the readings off-screen would have been a drastic reduction in light to measure at low IRE's IMO. A few folks prefer the CF/EyeOne off-screen method, but more pro's who gave me input didn't, The 'ol choose by forum opinion thing again.
FWIW, Cliff told me (hope he dosent' mind the quote) they use the very high $ sensors to do their meter and offset calibrations (as I'm sure all of them do) but he said: "No other manfacturer offers our screen offset function which in the end makes a huge difference as it takes into account the chromaticity shift of the projection screen surface. This can be considerable when one is using a Gray screen for enhanced Contrast. The error of the screen can be dialed out during the calibration to provide perfect results.
The offset file allows one to calibrate the projector with the probe
oriented towrds the projector which is an added benefit as there is
considerably more light available from this position then reading from the
screen. The offset has the user calibrating the projector as if it were
being viewed from the screen instead of directly to the White target (ie
D65) value that other would be adjusting to. Without the offset file the
degree of error can be anwhere from minimal to very objectionable."
I have a Firehawk. Several folks I spoke to felt the stewart screens, even the Firehawk were pretty neutral with color shift so it may not be a big deal in my case, dunno. I didn't ask Cliff about that screen specifically (yet).