Axiom Home Page Forums General Discussion Home Theater high cost of anamorphic lens

mdrew,

We did go and look at the Epson UB pro and JVC RS1 at a dealer. Unfortunately they were on much too large of a screen. The Epson was on a 100" 16:9 screen and the JVC was on a 120" 16:9 screen. We only compared a couple of scenes of Pirates of the Caribbean Blu-ray on both and couldn't notice a difference between the two projectors because of this fact. The larger screens were taking away the punch of the images and there should have been a noticeable difference stepping up to the JVC. The front row of the theater with the Epson was 13' away from the 100" screen and we both though that height-wise the screen was too big at that distance. To see the whole screen vertically you have to move your eyes up and down a little bit, which we thought would get old very fast. So we were thinking that at 13' we wouldn't want more than a 90" screen. If his front row will be at 10 to 12 feet then 80" to 90" would be fine.

From my calculations earlier the 87" 16:9 screen with a gain of 1.3 would have around 11fL (after 500 hours with an anamorphic lens using your 50%+10% reduction of brightness) on the Planar. The size of the 2.35 screen with the same area would be 37"x87" which is a good size at 10', I think. He doesn't watch any sports programs so 11fL at worst should be great in a darkened room.

I just found an article that agrees with you saying that you need 12fL to 20fL in a darkened room to have a nice punch to the image. But, it also said not to go more than 1.3 gain since you will start to introduce artifacts.

Here are a few excerpts:

"A screen is a passive device and can't literally amplify anything. It produces "gain" by focusing the light toward the center of the viewing area, resulting in a brighter image on- or slightly off-axis, but a dimmer image as you move further to the sides. High gain screens can also have hot spots; that is, they look obviously brighter in the center than at the sides. The higher the gain, the more pronounced the hot spot."

"High gain screens (over 2.0) can be useful if you insist on a very large screen, or have a projector with a very low light output. While some users swear by such screens, we generally don't recommend them. They are skewed toward brighter images, often sacrificing other important characteristics like color purity, brightness uniformity, and resolution."

"Different installations will have different requirements, but for most current home theater projectors you'll avoid serious problems if you stick with a screen width of 80 to 87-inches, with smaller screens giving you extra reserve to allow for lamp wear. If the projector has good blacks, we recommend a screen with modest gain (1.3 or so), particularly at the higher end of that size range. Very bright projectors may, however, provide better results with a screen gain of 1.0—or even a bit lower."

link: http://www.hometheatermag.com/advicefromtheexperts/707choosingscreen/


The last line, "Very bright projectors may, however, provide better results with a screen gain of 1.0—or even a bit lower.", we could instead keep the 1.3 gain and just go with a little larger screen say 100" 16:9. Also, maybe your figure of a reduction of 50% brightness after 500 hours on the lamps varies from brand to brand and may be less. In this case you could increase the screen size as further if it is say 30% or 40% instead, although this is probably hard to find published anywhere for a specific projector. Sorry for the long-winded responses, but I drank an energy drink earlier and still feel the caffeine (and whatever else they put in there) pumping through my veins.

- Nick