Digital Inputs
All the projectors have at least two digital inputs (HDMI and/or DVI), and some with three. All have the standard "low res" inputs - Composite, and S-video, and all have at least one component video input. The projectors with more than two digital inputs are:
The three Optomas in the HD80 series (HD80, HD803, HD8000), each have two HDMI inputs and a DVI input for a total of three usable digital inputs. The Optoma HD81 and HD81-LV, which have outboard processor boxes, have four HDMI inputs each. Panasonic's PT-AE2000U has three HDMI inputs.
All those with DVI inputs are HDCP compatible so count as the same as HDMI, for most purposes.
HDMI 1.3 Compatibility, Deep Color
At this point, all the projectors now support HDMI 1.3, which offers some future capabilities (mostly audio), but also Deep Color, which provides an improved color palette. Unfortunately not all projectors with 1.3 HDMI support Deep Color. I've been trying to get a handle on which don't. Of the 20 projectors, the two Sony projectors (both 1.3 compatible) do not support Deep Color, nor do the BenQ W5000 and W20000 which only have HDMI 1.2.1.
Computer Inputs
All of the projectors (with one brand excepted) have an analog computer input (although the BenQs do that with BNC connectors instead of the traditional HD15 "VGA" connector). The exceptions are the JVC projectors which have no analog inputs. This doesn't prevent them from displaying a computer source, but does complicate things a bit. For the JVC projectors, the computer signal can be displayed if it is DVI/HDMI, in which case it uses one of the HDMI inputs. This requires that your computer support DVI/HDMI. Most do not, but almost any desktop can be fitted with a HDMI output card, for the display. The same should be true for laptops. (My MacBook Pro, like most Macs , has a DVI output, so no problem with them.) Another solution is to buy an outboard box that will convert the standard analog computer output to either HDMI or to component video. Outboard boxes that do one or the other tend to start around $100 but are typically twice that price, or more. Let's just say, that if one of the JVC projectors is your top choice overall, then the relatively small extra cost for an external converter is negligible. I say small, since the JVC projectors, are some of the most expensive.
Anamorphic Lens Support
For those of you not familiar with anamorphic lenses, here's the scoop: Todays home theater projectors are all 16:9 aspect ratio. That is, of course, a perfect match for HDTV, where the image will use all of the projector's pixels, to fill a 16:9 screen (which is what the vast majority of home theater owners buy). Movies however, primarily use the Cinemascope format: 2.35:1. Because of this, we are all used to seeing black "bars" referred to as a letter box, at the top and bottom of the screen, with the movie in the middle. The letterbox area at top and bottom eats up about 20% of the screen's total area (roughly 10% above, 10% below the movie).
With the addition of an anamorphic lens placed in front of the projector's lens (an anamorphic lens stretches the image in terms of width, but not height), you can instead buy a Cinemascope wide screen, and fill it all with the movie, without letter boxing. For a projector to be able to use an anamorphic lens, it needs a special aspect ratio often referred to as vertical stretch.
Today, a very small percent of home theater projector setups are anamorphic, and most of those are high end buyers spending $30,000, $50,000 even $250,000 for their complete home theaters. My best guess, is that of those with under $10,000 projectors, probably no more than 2% have anamorphic lenses. I do believe that the trend is growing slowly. The high cost of anamorphic lenses is still a major deal breaker. The most popular lens, (with the motorized sled to move it in and out of the way when you want to watch HDTV and regular TV, movies in 16:9, and 4:3) tends to sell for around $3000, which is more expensive than more than half of the projectors discussed here. The high cost of the lenses changes the value proposition, of course.
Not all projectors support vertical stretch. That doesn't mean you can't add an anamorphic lens, but it means further expense, requiring the purchase of an outboard processor (they start at around $1000, but most are around $2000).
The projectors that do not support an anamorphic lens (having no on-board aspect ratio support), include: Both Epson projectors, the Sanyo PLV-Z2000, the JVC DLA-RS1, and the DLA-RS1x. Few projectors have a "trigger" to control the anamorphic lens sled. In an ideal world, the projector would recognize the cinemascope aspect of the movie, and automatically select vertical stretch and move the lens in place. In reality though, most projectors don't even automatically adjust for different aspect ratios. (Off hand, the Epsons and JVCs are two lines that do automatically, and there are some others). In most cases, you would use a remote provided with the lens' sled, or program that into your room controller (if you have one).
For those already owning a projector, switching to a setup with an anamorphic lens isn't cheap. Not only the big bucks for the lens and sled, but also replacing your 16:9 screen with a 2.35:1 screen. Most screen manufacturers, including of course, Stewart, Da-Lite, Carada, Draper, among others, offer 2.35:1 screens.
