For a LED projector, you can best look at the bulb wattage, to get an idea of lumen.
Most of the time, if the wattage is about 50Watt, ANSI Lumen are about 280-300 lumen, and peak lumen are about 1000-1500. Good enough for an 80″ display in a pitch black room, or 50-60″ indoors.
Unless you live out in the sticks where there’s no light pollution, it’s not a recommended projector for outside events, or perhaps with a smaller than 60″ screen diameter.
For projectors smaller than 50Watt, usually the 25 Watts are good for 50 lumen, and 1-8 watt projectors for upto 10 lumen (good for about the size of a pc monitor), I have very little experience with.
At 100Watt, it’ll usually have 500 ANSI Lumen, and 2000 PEAK Lumen. Bright enough for the 80-100″ bedroom screen, with some night lights on, but not a fully illuminated room. This projector might be just a tad too bright at 80″ for a pitch dark room, and is suited for 100-120″ in these conditions. It also works well with a 60-80″ screen in a normal lit room.
At 150Watt, it’ll usually have ~700 ANSI Lumen, with a peak of about 2800 to 3000 Lumen. Great for a 100″ screen outside, with minor light pollution. Too bright for a bedroom screen of under 100″, in a pitch black bedroom.
At 200Watt you’ll reach about the upper end of the (Chinese) LED projectors fabricated today. Some manufacturers like Casio make higher powered projectors by combining them with lasers; but at 200Watt, you’ll be looking at roughly 800ANSI lumen, and 4000 peak. Great for the outdoors after sunset, for screens of upto 120″, or in the bedroom upto 200″. Screens of this size are harder to get.
Some concert projectors have 3000 ANSI Lumen, so LED projectors are still a far cry from this. But for personal home entertainment, they provide quite a nice experience, and oftentimes of this writing (12/2015) $400+ projectors can easily replace HD tvs, in both energy efficiency, and overall experience, if you can live with the lower resolutions (of ~720p).
FULL HD (1080p resolution) projectors, at the time of this writing, are still too expensive to cover the cost.
Most 3D Ready projectors are not 3D capable out of the box, and only work with personal computers.
If you want to have a 3D experience on a projector, with 3D glasses, straight from blu-ray, there used to be $600 devices from Optoma and some other brand, but for some reason they stopped manufacturing them. I guess either the standard hasn’t been set yet as to which glasses and system to use to transfer the 3d content.
There is a $400 alternative, but works only with optoma DLP projecors. All others will have to go with a $2k Sony or JVC converter; which is way too expensive.
At the time of this writing, the first Chinese converter boxes are being manufactured, to work with active shutter glasses, either through RF, bluetooth, or IR, at an affordable price of $80.
At the time of this writing, it is not yet recommended to invest in a 3D home entertainment system, for at least another year or two, until finally a standard will be fully adopted by most manufacturers. The standard issue might make you buy technology today that will be outdated tomorrow (like how Blu-ray was chosen over HD DVD; and people with a HD DVD player (as well as a laserdisc) spent hundreds of dollars into a device that really got nowhere, and where there’s not a lot of content available for, and that which is, is oftentimes hard to get.
3D glasses come in several forms.
The easiest ones are the ones in the movies, passive glasses. These need a special screen, or projector with a special lens (polarized).
At the time of this writing, it is more common to see active glasses with projectors.
Of these active 3d glasses, there are those working on infra red signal emitted from the converter box, a bluetooth signal (these glasses need recharging), and an RF signal, which imho, is just radio (or microwave) waves going through your body that you want to avoid.
Let’s see what standards the future will determine will remain!
At this current moment, there are nice sub-$100 projectors available for kidsrooms, sub $400 projectors for the bedroom, or outside activity.
Casio $1k-$2k projectors are also great for outside movies, but are for those who have more $$$ to spend.
Most of these projectors can not convert the full 5.1 surround sound, but convert it to 2.0 stereo sound, which you can play back from a Tripath amp (search amazon or ebay for them), and a set of desktop speakers.
For outdoors, you can easily buy 2x 8″ 100W stage monitors, from Samson, Hartke, or Behringer. They all sound great for the money!
If you are aiming for a party of more than 10 people (eg: 50 people movie night outside), a lot of brands sell 12 to 15″, 300W stage monitors as well, or, you can use 4x 8″ 100W stage monitors,
2 speakers on the front for L and R channel, and 2 on the rear, for the coupling effect (louder sound in the seating area).