Is there such a thing as foot lambert being too high? If so, how high is too high? My room deminsions are 14L x 18W x 8H and there are no windows. I am looking to install a 100' 16:9 diagonal screen. At approx 11.5 to 12 ft throw distance I keep coming up with fl close to 30 and in some cases 40. I am having a difficult time figuring out if this is too high. Any thoughts would be appreciated.
foot lambert question
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I have been using projector central, which is where I got the standard 16 Fl. I have also been looking at the sony VPLHW40ES projector and I am getting Fl of 25 using the calculator on projector central. I have also looked at the cheaper Optoma HD141X, which has a 42Fl. Any thoughts on if these are too high and how this would impact the view?
Personally I wouldn't call the Sony you mention too bright. I like how bright it can get. Keep in mind that you could always tweak the brightness down with a external filter over the lense or by using low lamp mode if it's too bright for your tastes. And the bulb will dim over time anyways.
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I wouldn't use the Projector Central calculator for brightness - it uses the manufacturers specs., which are frequently overstated. Get real lumens from a good review site like this -
http://www.projectorreviews.com/sony/sony-vpl-hw40es-home-theater-projector-review/
And yes, you can have too bright a picture. 16 - 20 foot lamberts is good in my opinion.
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No such thing as too bright.
Actually, there is, but it can be dealt with.
If you find that your projector is overly bright then you can typically put it in 'eco' mode, which will reduce brightness. There are typically other settings to reduce brightness as well.
From there, if it's all calibrated, and still too bright, you can pick up a ND filter (neutral density) filter, and connect it to the front of your projector's lens. This is basically like putting sunglasses on your projector and will reduce light output to more acceptable levels.
Easy to make things dimmer, tough to get more light if you want/need it!
Lumens measured (call it 500) are divided by the square feet of your screen. Call it 25. 500/25=20 lumens per square foot or 20 ft/lm.
Actually, there is, but it can be dealt with.
If you find that your projector is overly bright then you can typically put it in 'eco' mode, which will reduce brightness. There are typically other settings to reduce brightness as well.
From there, if it's all calibrated, and still too bright, you can pick up a ND filter (neutral density) filter, and connect it to the front of your projector's lens. This is basically like putting sunglasses on your projector and will reduce light output to more acceptable levels.
Easy to make things dimmer, tough to get more light if you want/need it!
Lumens measured (call it 500) are divided by the square feet of your screen. Call it 25. 500/25=20 lumens per square foot or 20 ft/lm.
There are many factors that can determine whether it is "too bright".
One is whether the lights are out completely in the room. Not everyone likes pitch dark, some like some lights on over the seating area to be able to see remote controls, pick up a drink without knocking it over, etc. so even if it CAN be pitch dark you may not prefer it.
Another is the size of the screen, since dividing a given amount of light over a larger area makes it less intense. You are talking about a 100" which is very small for your room size and is only 30sf in area. You have the space for a 150" screen in your room and at 66sf would be less than half as bright. Given a real-world 1500 lumen projector, you should see 1500/66 = 22 foot lamberts. This is actually about what you want, as you can start in eco mode and be about 30% dimmer or 16fl, and then switch to normal as the lamp ages so you get some of the original brightness back.
The brightness is also affected by the "gain" of the screen material. Gains less than 1.0 will not be as bright as the calculation above. Some grey screens have gains of only 0.6. With a completely dark room -- and dark painted walls and ceilings, right ? -- you have no need for anything other than a plain white 1.0 surface.
Very few people ever decide they chose a screen too large -- we invariably go bigger with our second screen purchase. As long as you are considering projectors that have the necessary brightness -- like the Sony, Epson 5030, or Benq -- I would start with my seating distance and determine proper screen size based on the height being half the distance to the front row of seats. It is especially important not to pick too small a screen if there will be more than one row of seats, because a larger screen will minimize the difference in field of view for movie watchers. For a front row at 12', a 150" screen is about as big as you want to go, but is barely adequate for a second row at 18'.
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Another point to consider on brightness is that some people are conditioned to viewing images that are "too bright." Many are used to watching overly bright LCD TVs that they never take out of torch (display) mode and adjust to proper home lighting conditions even when viewing at night. Proper front projection brightness of 16 foot-lamberts is based on replicating the experience of commercial movie theaters. Anyone with a personal preference for brighter, punchier images may find 16 foot-lamberts too dim even though that's what filmmakers intended their audiences to experience.
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