If you like to judge a projector based on how well the product meets the manufacturer's claims for brightness, then run the other way. If you want to judge the HD33 base on it's real measurements, then read on, knowing that the HD33 projector still has a goodly number of lumens, even if it measured about a full 1/3 down from it's 1800 claim. Optoma wins no points for the exaggeration. Companies that can't deliver brightness with a watchable picture within 20% of brightness claim annoy me. Regardless of everything else, I looked forward to a projector capable of almost 1800 lumens, one much brighter than any previous 3D projector to come through here, and instead I found a projector only slightly brighter than those others. I'm disappointed.
But, judge the projector based on it's bottom line performance, ultimately, that's what you are buying. I just feel sorry for the folks that don't do any real research and buy this projector over some other, due to expecting more brightness.
OK, enough complaining on my part.
Let's look at the HD33's numbers:
First, all the modes are pretty similar in brightness. Certain controls, though can affect brightness, such as a slight increase when using the higher Pure Color settings...
Those numbers are all "right out of the box", without any adjustments, to settings like contrast, which can affect overall brightness.