How to increase black levels
Several folks have asked what Neutral Density filter they should buy to increase the black level of the pro8200. That question can’t be answered because it depends…
This has been my experience with projectors so far. I’m sure more knowledgeable people will chime in.
I’ve watched one movie so far, and it had no dark scenes, but the projector OOTB seems to blow out the highlights. I noticed the same thing watching HDTV. It’s just too bright!
But first, if you have any ambient light in the room and if your walls and ceiling are light colored, forget about inky black levels. Couple this with the light leakage from the projector and you fighting a losing battle. First you have to control the light bouncing around the room. I don’t think enough exclamation points can be added to that.
Paint the walls a dark neutral gray. Any color on the walls will affect the color balance of the projector. This can be used to your advantage if the projector has a problem with a particular color. Since the whites tend toward red, you might go with a blue-gray color for the walls, which would tone down the red without needing to raise the color temperature.
Since a ND filter is doing nothing but cutting the amount of light evenly across the color spectrum, how dark a filter you might need depends on the screen size, the throw distance and how dark your room is.
The standard for movie viewing is 13 foot-lamberts, but you’ll read on this forum folks that run as little as 4 foot-lamberts in their home theater.
So if your goal is 10-13 fl for movie watching, the amount of lumens the projector needs to produce is a function of the square feet of your screen. The formula is FL X Area(screen sf) = Lumens, or Lumens / Area = Foot Lamberts.
Projector Reviews measured this projector at about 850 lumens in Dark Room mode, which pretty much is in line with the fl calculations of the projector calculator on the projectorcental website.
Here’s some calculations from the screen calculator there using the midpoint of the throw distance assuming a gain of 1:
100” screen(29 sf) @ 12’4”= 29 fl, which calculates to 841 lumens.
120” screen(44 sf) @ 14’9”= 20 fl, which calculates to 880 lumens
135” screen(54 sf) @ 16’7”= 16 fl, which calculates to 864 lumens
Some variations, and slightly above the measured lumens in Dark Room mode, but certainly in the ball park.
Here’s at the far end of the throw distance:
100” screen(29 sf) @ 15’6”= 25 fl, which calculates to 725 lumens.
120” screen(44 sf) @ 18’8”= 17 fl, which calculates to 748 lumens
135” screen(54 sf) @ 21’= 14 fl, which calculates to 756 lumens
As you can see, you can tame the light somewhat by moving the projector back, but that makes it even more important that the walls are dark to minimize reflected light.
I would suggest you have all your guests wear dark clothing when watching a movie. LOL
Now, assuming you’ve completely controlled the light in the room and the projector is at the mid-point throw distance, you want to shoot for 10 fl for movie watching.
With a 100” screen you would want a 1.5 stop ND filter. (Actually a little less)
With a 120” screen you would want a 1 stop ND filter.
With a 135” screen you would want a .5 stop ND filter. (Actually a little more)
Here’s the ND filter I ordered. It’s a sheet of polyester gel rated at .5 stop. I’ll probably cut it to fit the snout on the projector and tape it on. You can just stack the filter to get the 1 and 1.5 stop. Then you can move the projector and change the throw distance to fine tune the fl. Once you’ve decided you like the results, you can replace it with a glass filter if you want. I used a CC40 poly filter on my Hitachi without any noticeable degradation for several years.http://www.bhphotovideo.com/c/produc...l_Density.html
But with all this talk of black levels, shadow detail, to me, is more important. There is nothing more frustrating with a dark scene that is nice and black, so black that I can’t make out what is happening. And according to the review, the projector does this well, at the expense of overall black levels:
“All considered, the Pro8200 reveals more of the dark shadow detail than just about any other projector we've recently worked with. Most impressive. In reality it was essentially identical to the HC3800, but our photo of the Pro8200 is a little darker.” – Art Fein
Hope this helps.http://htrgroup.com/main.php?section=brightness