how many lumens for a HD projector do i need for this room?

Question

how do i tell how many lumens i need?

Answer 1

Other responses are OK, but don't really provide all the info you need. The rule of thumb -- for a light controlled room -- is to have about 15 foot Lamberts (fL, see link) of light (the incident illuminence) on the screen. Actually, 16 is the minimum for movie theatres. But more is not necessarily better since more than about 25 fL begins to get too bright (except when competing against ambient light).

Illuminence is a factor of projector brightness (usually measured in actual (vs rated) ANSI lumens, throw distance (lens to screen distance), screen gain and screen size. Note that rated lumens quoted in projector specs are usually 50->100% higher than actual (HT optimized for colour accuracy) brightness). For a given projector, greater distance to the screen and the larger the image the lower the illuminence, and the higher the screen gain, the more the illuminence.

This can be calculated experimentally using suitable instruments, but the easiest way to find out for usual purposes is to use the Projector Central "Projection Calculator Pro" (see second link). This on-line tool allows the illuminence to be estimated for specific projectors and uses (e.g. presentation, movies) as a factor of throw distance, screen size and aspect ratio and screen gain. The current value for a given set of conditions is even indicated using a colour code (with green indicating suitable values).

Sooo ... pick your projector, and input the values for your intended setup, and adjust as necessary to optimize the estimated illuminence. A less mathematical way to get confirmation is to read reviews of projectors of interest at projectorcentral.com or projectorreviews.com and pay attention to their comments on actual (vs rated) brightness, screen size and type recommendations.

Hope this helps.

Answer 2

The problem with trying to do this mathematically is that the pj manufacturers are very stingy when they list their lumen ratings. I've found plenty of pj's listed as 800 lumens that look like 2000 depending on the ambient light source, so you could end up wasting money if you get a 1500 lumen pj that looks like 2500 lumens.

My reccomandation would be to visit

www.projectorcentral.com

and check out the reviews. My personal preference is the InfocusIN72 (480p) or IN76 (780p) DLP projectors. You can get both for less than $1000 easy, and I think they look great.

Secondly, like I tell everyone else, there are so many projectors and opinions out there that you can really get confused if you listen TOO much. Just find a pj with good reviews with about 800 - 1000 lumens and pull the trigger. I bet you won't be dissapointed with whatever you get

weeder

Answer 3

The lumens depends on the lighting (controllable?), gain and material of the screen, projection distance and size of the image. There is no magic number for all rooms.

If you can control the lighting, you probably can live with a 1000 lumen projector. If you cannot control the lighting, then you probably want 1500-2000 lumen projector.

The larger the image, the dimmer the image will be. If you keep the image under 92 inches, then the above specs should be fine.

If you get a standard gain screen, which is 1.0, then the above specs should be fine. Obviously, a higher gain screen will reflect more light and provide a brighter image to compensate for a low lumen projector or high ambient light.

If you are serious about your home theater, consult a screen manufacturer and they will help you. If you don't want to spend alot of money, then you can try it yourself.

Answer 4

There is no way to tell in advance .All modern home theatre projectors have enough lumens for any room.It depends how dark you can make the room.Anyway resolution and contrast specifications are just as important as brightness .The whole three determine the quality of the image you get.

Answer 5

The size of the screen, distance to the screen and the lighting in the room are key factors. Lighting being the most important. If you can make the room really dark when you watch the movies - you can get away with under 1000. If the room is light - you might go as high as you can - from 2k up.
Best is to consult the store or the installer.