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Calibrating with Dynamic Black ON is not going to be as easy as you might think -- I haven't thought about this in GREAT depth yet, but it seems to me that to get best results if you want to use Dynamic Black is to do calibration in 2 phases. This will be required to get decent results...

Phase 1 - Turn Dynamic Black off and calibrate everything as best you can

Phase 2 - Turn Dynamic Black ON to the setting you plan to use and as you fine tune grayscale steps and even colors, you will need to make your adjustments so that you do not change the luminance of the step you are adjusting. For example. Let's make this easy and say with DB OFF you calibrated the grayscale and you measured 10% White at 0.1 fL and you set your gamma to 2.25 (with variations in gamma that are practically inevitable, you managed to maintain your gamma between 2.2 and 2.3 for 10%-100% white). Now remember, this is with DB OFF. OK, so now you have a good grayscale and good gamma. Now, you turn DB ON and pick your setting/level (1-3). For whatever reason, when you measure some steps, especially darker steps, there are color shifts you need to get rid of. So now you measure 10% white as 0.05 fL due to the action of DB. In order NOT to screw up that gamma you set when DB was OFF (remember, your result where each grayscale step was between 2.2 and 2.3 gamma), you now need to remove some green from 10% white but when you do that, 10% white is going to get quite a lot dimmer... you don't want to let that happen. You need to make your 10% adjustments but you have to keep your luminance at 0.05 fL. So you can't just take out some green. If you were to determine that -4 on green would "fix" 10% white... your luminance level might drop to 0.04 or even 0.03... you can't let that happen. To keep that from happening, you might have to make your adjustments something like -1 for green and +3 for red and +3 for blue. That way you are removing green but also adding red and blue to keep that step from getting dimmer (these numbers are samples only, each projector is going to respond differently).

If you maintain luminance of each step after you have calibrated with DB off, you should maintain your gamma performance pretty darn well.

Similarly, when adjusting colors (red, green, blue, cyan, magenta, yellow), one of the things you SHOULD be looking at is color luminance. After you turn DB ON, your first measurement of each of the 6 colors will give you the target luminance for each color that you want to maintain as you make each of the 6 colors accurate. If your Red luminance was 3.36 fL, for example (with DB ON) but you need to tweak red to make it more accurate, you will want to do what you can to maintain that 3.36 fL of luminance which may mean making adjustments of multiple controls to keep your luminance at 3.36.

Doing this should allow you to use DB (or Auto Iris) while not introducing odd gamma behavior as image brightness goes up or down in response to the iris or changing light levels of the LED light source at different calibration settings. You may be used to having your d65 target (x=313, y=329), but luminance determines gamma -- so when adjusting any step AFTER the DB-OFF phase of calibration, you must maintain the DB ON luminance you began with... skipping that step is how we get those strange gamma results when using DB or Auto Iris.