Projectors can get very complicated very quickly. They have all of the same complexities as other HD TV devices in terms of resolutions, input types etc, but also added complexity due to the open air between the projector and the screen and the parameters of the screen itself, and difficulties creating black and white given the lack of control of light sources/reflections in a home projection environment.
The main projector technologies are CRT, LCD and DLP.
CRT (or Cathode Ray Tube) is the technology on which traditional TV sets and computer monitors were built before LCD became widespread. CRT is flexible due to its ‘electron beam’ as opposed to fixed resolution, allowing many different resolutions to be displayed, and also very accurate colours and black. It also has a long projection life, at around 20,000 hours vs. about a tenth of that for LCD/DLP. However as with its TV equivalent, the CRT projector is a bit of a beast in terms of size, and requires a dark room to be viewable. Furthermore, the upfront investment is very large (back into new car vs. projector territory). This is, in my opinion, not a great idea for a home projector. Maybe if you’re starting up a small cinema it makes sense.
LCD projectors pass light through a small trasparent LCD chip that creates the projected image. They are significantly smaller and more reasonably priced than the CRT projectors. However watch out for a ‘mosquito door’ effect, which makes it look like the screen is being viewed through a fine wire mesh. With a good LCD, this effect is difficult to notice. As with LCD TVs and monitors, dead pixels can be a problem, and cannot be fixed.
DLP, a patented technology of Texas Instruments, gives light colour using spinning coloured filters, and then reflects the light out through the lense using a number of micro-mirrors. The micromirrors are controlled by small tilting mechanisms, which can thus control the composition of the image. This generally gives better image quality than LCD, the only downside sometimes being a ‘rainbow effect’, but this effect is unnoticable to most people on high quality DLP projectors. Furthermore, LCD is rapidly improving to the point where it is more and more difficult to distinguish between the two. DLP is slightly more expensive than LCD due to the complex proprietary nature of the technology, but achieves a slightly better result.
Both DLP and LCD have a bulb life of 1,000-2,000 hours (with bulbs degrading in terms of brightness and contrast towards the end of their lives, and with replacement bulbs costing about 10% of the cost of the projector). Depending on usage, this can become a significant ongoing cost.
The screen is very important, and it is quite easy and potentially sensible to spend more money on a screen than on the projector it is being used for. This is because once the screen is installed, it makes sense to keep it. Therefore it is helpful if it is future proof, even after you have replaced the corresponding projector. Screens don’t go out of date very often, so it makes some sense. The clear market leader in screens is Stewart Filmscreen, but they are very expensive, and there are many different No.2 players depending on who you ask. Da Lite is one, but there are many others.
Screens can be white or grey depending on the ambient light in the room, and the level of ‘reflectiveness’ of the walls, ceiling and furnature. Grey screens cut out more of the ambient and reflected light, where as white gives a slightly brighter picture.
Distance to screen/laying out your livingroom
Depending on your desired image size and the optical zoom available on the projector you’re looking at, you need to make sure you can mount your projector far enough away from the screen to get the image size you want (you may even find your livingroom/basment isn’t big enough!). Be sure to check out a projector calculator to see if your viewing distance and throw distance (distance from theÂ projector to the screen) make sense in the context of the zoom available on a particular projector, and the desired image size. I recommend the calculator on www.projectorcentral.com (Calculator Pro, towards the bottom of the left hand bar).
Summary and final notes
Fighting your way through what can only be described as a jungle of projector-related decisions is tough. The upside is that it is only with a projector that you can get a high quality picture that is larger than 60 inches at a reasonable price, and that cinema-feel (having light projected past you in a darkened room) comes free to boot. However you should also factor in the cost of the screen, the ongoing cost of the bulbs, and the cost of doing whatever else you might need to do to the relevant room when making a purchase decision (mounting of the projector/screen, black-out curtains, replacement of any fixtures/furnishings that get in the way etc).
In the end I went for a DLP projector, although at time of original writing (early 2007) I hadn’t yet picked a screen. I didn’t go all out for a Mitsubishi HC5000 (which I believe is probably the best bang for your buck for a ‘full HD’ 1080p projector based on what I’ve read) and instead went for a 720p InFocus IN76 (narrowly beating out the Optoma HD72) given that it was my first projector, and I’d rather not fork out too much on something I’m not absolutely certain is essential for my survival.
The IN76 – my final decision
The final two considerations I would leave you with are noise and image size.
Some projectors are supposed to be noisy, but even though the InFocus was supposed to be noisier than the Optoma, I certainly never notice it. In retrospect I think that noise is a non-issue, overblown by obsessive, basement-ridden ‘cinema enthusiasts’.
On screen size I would warn you that I had put something up on the wall to get a feel for how big an 80 inch diagonal 16:9 widescreen image would be. I thought that I couldn’t possibly need a bigger screen than that. Then when I got the projector home and switched it on, I decided that I had to have at least 100 inches and had to cancel my screen order. The moral? Set yourself up for the biggest screen you can beforehand because if you do opt for a projector, you will want to squeeze all the juice you can out of your new toy.
Home-made projectors and screens
Just wanted to flag this – didn’t work for me because I’m after better quality, less space and less work rather than something cheaper. However I still think it’s awesome, and I guess many people will agree.
end of sidenote/