If someone walks in front of the screen and blocks the beam, it's only for a second or two AND someone passing by with a short-throw projector may not block the beam but will still be between you and the screen and blocking it just like someone walking in front of the TV. I wouldn't limit yourself to short-throw for this reason, it's a huge limit for a fairly trivial reason that the short-throw won't always fix anyway.
Manufacturer listed contrast is a lie outside of the medical industry and the real-life measured contrast of all those DLP projectors you listed will be visually the same..VERY similar.
To a lesser degree, brightness specs are somewhat policed (unlike contrast, where chaos rules) but brightness numbers are still easy to fudge to a pretty large degree. Don't expect any lamp-based projector to be brighter than 1400lumens in a decent looking setting, and expect a non-RGB DLP (any rated 2500-3500lumens) to only give around 600-750lumens..ironically it's the 1000-2000lumen-rated ones that will be brighter in accurate settings.
Likewise, no matter what they claim, you won't find an LED or laser/LED-hybrid that puts out much over 500lumens in any decent looking mode. Also, full-LED models tend to be more stable than the hybrids..so don't be fooled by the exaggerated brightness claims.
In a dark room (all projectors look fairly poor in a lit room), you're aiming for about 14fL from that calculator..basically everything will be fine for a 85" screen. 500lumens is usually good enough for most people up to 100". Going bigger than 100" can have some people looking for more than 500lumens and different folks prefer different brightness levels. Movie theaters aim for 14fL. Most theater 3D films are around 2fL-3.5fL and aren't set to look good at such low brightness so it's a common complaint, but many are very happy as low as 10fL.
That 10,000hour lamp-rating isn't a real use scenario, the actual use life will be closer to 4000-6000hrs for both of them. If you used it for 4hours every day, it should still last about 3years before needing a new lamp. Toss $8 in a jar each month if you use it a ton.
If you want an affordable lampless projector, that LG pf85 or upcoming pf87 is the best there is if you can get past the non-short-throw. Otherwise, look for a 1080 native resolution DLP rated for 1000-2000lumens by a reputable brand like Benq or Optoma. If you can't find that within your price-range, either lower native resolution to 720/wxga OR raise claimed brightness up to 2500lumens. I'd lean towards the lumen raise if you watch a lot of bluray.
Almost every LCD projector under $2000 has significantly worse black-level than even the poorest DLP, so stick with DLP unless someone is particularly RBE-sensitive which is pretty rare.
Last edited by Ftoast; 07-26-2014 at 08:29 AM.