Need help to calculate brightness

Thanks for that helpful reply... so, essentially, with the ND filter, my 5700 and the MK2 would have about equal brightness. And I'm guessing lamp fade is probably the same with pretty much all units.


I guess the other important factor would be the lumen rating after callibration for an optimal picture... I took a look at the review in the link you sent and found this:

"With Economy on, and with the High Brightness mode of the Iris, the projector produced 15.3 ftL on my 102” diagonal unity gain (gain=1) DaMatte screen... In the Medium mode of the Iris, (Economy on), the light level at the screen fell to 7.1 ftL (218 Lumens), but the contrast ratio increased to 3085:1. In the High Contrast Iris mode, the light output fell further to 6.3 ftL (195 lumens), but the contrast ratio rose to a remarkable 4394:1. All of these measurements were made with approximately 100 hours on the bulb."


The 102" screen size is very close to my 105", so in it's "best picture" mode, the Mk II would give me maybe 7 ftL.


Without callibration or bulb wear, my 5700 is giving me about 15 ftL. After 1600 hours on the bulb, how much should I reduce that rating?


I don't know that I would reduce it much further due to callibration, since most reviews of the 5700 said the performace was pretty solid right out of the box.


Also, I can't seem to find a review that says if the 5700's 1000 lumens is with high power mode or not... I'm assuming it's in high power mode, since most manufacturers want to list the highest possible number.... I always run in low power mode, so maybe I can knock another 20% off my current brightness, which brings me to maybe 12ftL, not counting bulb wear.


So the Sharp has 7ftL, my 5700 currently has 12, minus bulb wear.


Ok, enough thinking out loud, any more comments or ideas?

I've actually read the black level on the 7210 isn't so hot... but aside from that, the 7210 isn't a very long throw unit, and I need to cast a 105" image from 18 feet back.


According to the Projector Central calculator, the 12000 is one of the few units that would work for me.


And it's a private seller who wants to upgrade.


Generally speaking, how much of a reduction in brightness is a 3000 hour bulb at the 1500 hour mark?


And while I absolutely agree that the Sharp should have a much better black level natively, remember, I am using an ND2 filter in front of my 5700 which dramatically improves black performance.