Projector and Screen recommendations

If your room is "not real dark", and you want to do this at "rock bottom prices" . . . then you really should be looking at a plasma. But I'm a quality-over-quantity kind of guy. If you're still going to do projection, the least you can do is to avoid a few very common pitfalls.

First, make sure you're using the correct type of screen for your application. If the projector is going on the floor or a table, then you can use a retro-reflective screen - these are the common, cheap glass-bead audio-visual screens. But if it's going on the ceiling, then you MUST use an angular-reflective screen, or the only time the picture will look good is when you're standing on a ladder. A good screen also hangs flat . . . tab-tensioning is IMO a good investment if the screen is retractable. If your room isn't very dark, then there are a couple of grey-coated gain screens on the market that make a huge difference, i.e. Stewart's "Firehawk" (and the Da-Lite equivalent). You will want an actual 16x9 screen - having the picture framed in black makes the contrast appear much greater than the 16x9 projection area in the middle of a white field.

Second, make sure that the projector's optics will work for your application - that is, double-check the throw distance AND the vertical offset and make sure that the projector and screen will work together in the place you're planning on putting them. Avoid having to tilt the projector (creates a focus discrepancy between the top and bottom of the screen) and using the electronic keystone adjustments (increases scaling artifacts).

And third, put up the SMALLEST screen you think you can tolerate! Brightness follows the inverse-square law, so making the picture somewhat smaller (i.e. from 100" diagonal to 82" diagonal) makes it much, much brighter.

If you get a good screen of reasonable size, and make sure that all of the projection geometry is set up correctly . . . this will make a MUCH bigger difference in picture quality than whether or not your projector happens to have "1080p" printed all over the shipping carton.

A retro-reflective screen throws light back directly towards the projector, just like the reflective coating on highway signs. The traditional material for these kinds of screens is tiny beads of glass (just like road signs). They work best for situations where the height of the projector lens is about the same as the height of the viewer . . . so they're the usual choice for general-purpose classroom and conference-room applications, where one usually just plops the projector on a table.

An angular-reflective screen is designed to be used where the vertical angle to the projection lens is the complement of the vertical viewing angle. They're generally used with ceiling-mounted projectors, because the projector is much higher than the viewers, and the height of the (center of the) screen is somewhere in between. Most modern high-performance screen materials are angular-reflective.

Both of these attributes have to do with the "gain" of the screen, which is a measurement of how directional it's reflection characteristics are . . . kinda similar to how directional a speaker is. A perfectly matte-white surface is considered to have neutral gain (gain of 1.0), that is, it's both retro-reflective and angular-reflective to exactly the same degree, and reflects absolutely all of the light that hits it. Screens with a gain higher than 1.0 increase brightness (and contrast) by sending more light in a particular direction . . . provided, of course, that it's in the direction of the people watching it. If it's the opposite direction (wrong screen choice) then it DECREASES brightness and contrast. Gains of 1.3 to 2.0 are typical for front-projection home theaters.

There's also the matter of the grey coatings used on some screens - what they do is improve black levels by absorbing some of the ambient room light. Of course, the screen doesn't differentiate between room light and projector light, and a coating like Stewart's "Greyhawk" actually has a gain of less than 1.0 . . . I think it's about 0.8. This is a good screen for applications where you're making up for the loss in light by spending more money for a brighter projector. On the other hand, Stewart's "Firehawk" coating is grey and has a gain of 1.3, so it "gooses up" both the black levels and the brightness . . . making it a great choice for a more budget-oriented home theater. The tradeoff with Firehawk is viewing angle (nothing is free) . . . so you definately need to get the projection geometery set up optimally to get your money's worth out of the screen.

The other benefit of a gain screen is (when set up correctly) if the ambient room light comes from a different direction than the projected image, you get double the benefit, because the ambient room light isn't reflected towards the viewers. So in a typical home theater, the WORST place to have an ambient light source is directly behind the seating area. And for an angular-reflective screen and ceiling-mounted projector, recessed lighting (with BLACK trims) is definately the way to go, as this reduces glare from a critical direction, if the lights are to be used at all with a picture on the screen.

And finally for your application, you have to be concerned with the opacity of the screen, because you're also using it as a shade to block out room light. This is an area where many of the cheaper screens have problems . . . and it's also not usually possible to mount the screen so close to the windows that this really works very well. Usually these windows will require shades as well.

Oh and your screen-size choices are refreshingly sensible for a budget theater . . . I can't tell you how many times I've seen people try to use a $1200 Powerpoint-grade projector on a 120" screen with ambient room light, and then come to the conclusion that "projection looks bad". Go figure.

The classic calculation for screen brightness is:

Projector Lumens / Screen area (sq. feet) * screen gain =
Brightness (in foot-Lamberts, or fL).

Target brightness is 12-15 fL in a darkened room, maybe around 20-ish with a little ambient light. But here's the catch -- projector "ANSI Lumens" specifications are so hyped and inaccurate, that a good rule of thumb is to take the projector's ANSI lumen specification, and use ONE QUARTER of this advertised value in your calculation. No kidding, those numbers are really that unrealistic.

Grey screens with gains above 1.0 are made by Stewart (the aforementioned "Firehawk"), and Da-Lite ("High-Contrast Cinema Vision") - I'm sure there are others, too.

Oh and I would personally prefer watching movies with a good two-channel "music" system than a typical receiver-based surround system. But that's definately a preference thing, some people feel the opposite.

Hi Semi,
One thing that seems to accentuate the perception of being "too bright" is if you actually have some "hot-spotting", meaning that your picture is brighter in some areas than others. This occurs with higher-gain screens with short projector throw-distances, because the relationship between projection and viewing angles varies more across different points on the screen as the distances get shorter. 1.8 gain is 'high-ish' for a home theater with a DLP/LCD projector, and your throw distance (less than 2x the screen width) is somewhat on the short side. If you can get the projector further away, or even try it temporarily, you might see if this makes an improvement. I'm assuming of course, that you've set up your black and white levels correctly.

Hi Russ,
The modern "microperf" screens are very good in terms of audio quality, especially when they're used in front of the center channel only . . . which to my ear needs more X-curve compensation (HF rolloff) than the other channels for movie soundtracks.

There is also an optical tradeoff with a perforated screen, that is, at the very least, you lose some brightness . . . this really hurt in the days of CRT projectors when lumens were very, very expensive. But you also need be careful of the reflectivity of what's behind the screen, as sometimes this can show through the perforations.

The best-sounding multi-channel system I have ever heard (by far) is the 5.1 system in Transparent Audio's listening studio . . . big Wilsons (Alexandrias?) all the way around, with a custom Wilson sub the size of an average refrigerator. The projection screen was a Stewart microperf that came down in front of the center channel . . . and in several scenes I could catch a glint of the shiney black Wilson through the screen, and it was a bit distracting, especially given how amazing the picture and sound quality was otherwise.