I'm not sure what situation you are in, so perhaps you could elaborate...

For home theater, 3,000 lumens is WAY to much light for 133" screen generally speaking.

For business, it could work properly, but I believe that rear projection tends to offer about 1.5 gain and often has a narrower viewing angle than front projection, yet it allows for greater ambient light in the room you are in.

If it is home theater that you intend to use it for and the room you are in isn't overly bright, than any decent home theater projector should work fine. Something like the Epson 8500UB would likely be excellent.

If it is a business setup where lights will ALWAYS be on, then a 3,000+ lumen projector likely makes a lot of sense.

Quote (clarakwan on Oct 7, 2009 1:13:21 AM): I want to find a projector for my rear projection screen (133"). There is a rear projection room behind the screen, and all lights are turned off in this rear projection room. In this situation, can I source projector which has fewer lumens (say 3000 lumens)? As my understanding, the fewer the lumens, the lower the price of projectors. Is it true?

Here are the elaborations:
- It is a system designed for business use
- Size of room for audience: about 500 sq feet
- Ambient light of room for audience: most lights being turned off, there will only be dim lights enough for audience to walk round the room
- Depth of rear projection room: <2m
- Ambient light of rear projection room: Very dark (all lights being turned off and no windows inside)
- The whole system is on for 8 hours a day

In this case, is 3000 lumens-projector suitable? Many thanks for your help. What are "lumens" for actually? If the projector's lumens are more then needed, what will be the effect? Will it affect the quality of projection?