I'm someone who installs and calibrates projectors regularly. I see them in manner of installations from dedicated bat caves through to family livingrooms through to bars and pubs. So I just wanted to address a couple of the points raised by Somnambulist
Because things like the news, Neighbours or Countdown just look silly when they're 100"+ inches in size
Granted, Freeview and some of the SD Sky channels don't look great. But remember, this is equally true as we go for ever larger TVs in our living rooms so it's not just limited to projectors.
If you plan to watch a lot of TV then a scaler can be used to shrink low quality channels down to a more manageable and forgiving size. I have a few used scalers from upgrading customers systems that would be perfect for just that sort of job. All are quality items that sold for £700 - £1000 new, but can be had now for between £50 and £100; so it's certainly not an insurmountable problem.
...when you switch to movies, 90% of the time because of their aspect ratio they'll look smaller, which is sort of the opposite effect you want with home cinema. You want movies to be bigger and better than regular TV, not smaller.
Again that's exactly what happens with a TV based home cinema system... except with a projector everything is much bigger.
I know what's being hinted at here, and it's right. In a perfect world there's a TV and a projector in a room; but hey, life's full of compromises too.
...a crappy SD broadcast isn't going to look great when it's over 2m tall and more than double that across.
TBH, that sort of screen size is too large for most UK homes. It's an 11.5ft wide x 6.5ft high image. I have a couple of customers with that size of screen, but these tend to be in games rooms where there's enough space to comfortably accommodate a party with 40-50 guests.
A far more realistic size for an average living room is 6-8ft wide (82"~110" diagonal) with a viewing distance of around 9~16ft respectively.
Blinds won't be good enough on bright days unless they're of the blackout variety, and even then because most people have light reflective ceilings and walls, so the image will still get washed out slightly (unless you have £2K for a Black Diamond screen).
The blinds comment is correct which is why you'd probably go for curtains with a blackout lining. That's what I've got at home.
The quality of projection in high ambient light really depends on...
a) what's being viewed: football or any programmes shot in bright studios or outdoor daytime will be OK
b) a sensible screen size combined with a projector that is reasonably bright. Some of the budget projectors chuck out a decent amount of light for lighting up an 82"~96" screen
c) some skill in how and where the room is lit. I install lighting and can design a room lighting plan that would give enough illumination to read a newspaper quite comfortably but still give a very acceptable picture brightness for TV
You can project onto walls, but generally a screen is preferable,
I'd go a little further and say that a good screen is essential.
A decent screen is an engineered product. It is designed to reflect light equally across the colour spectrum and to do so without causing a distracting hot spot glow. Better screens reflect more light and make the image look brighter than cheap alternatives or projecting on the wall.
Projectors also require a bit more care than TVs, otherwise you'll do the lamp in and then have to fork out £100+ for a new one.
Treat the projector the same way as you do a PC - shut it down properly rather than just pulling the plug. That's all it really needs.
Lamps also have a variable life expectancy, so you have to take replacement costs into consideration, even more so if you plan on only using the projector (because you'll rack up hours that much faster).
Firstly, I'd say if running costs are your prime consideration then don't buy a projector. It's just like any device that needs consumables to run. You wouldn't get very far in your car if you didn't buy petrol for it. It's the same mindset with a projector. Buy it to enjoy because it's a damned sight cheaper than a 96" TV.
Extended viewing is actually good for the lamp! What kills lamps is the start up and cool down sequence. Watching for several hours may rack up more hours but it involves less starts than someone using theirs for shorter stints.
There's also all kinds of things like throw distance and mounting it in the right place, how bright the projector is, sorting out the wiring from ceiling to amp/receiver, surround sound(?), e.t.c. It's not like a TV where you can just buy one, plug it in and you're ready to go.
Again another mindset thing. We're a resourceful bunch here in the OCUK forum, and these are hardly the most challenging obstacles to overcome.
