16 FOOT WIDE Movie Screen at home help please


xx.
Until now, I have been throwing a 12ft x 9ft image on a blank wall that is approximately the color of the pale yellow that the page you are now reading. The projector is about 20 feet away from the wall. For three or four years, this has been very satisfying to view movies.

My projector is a Sharp XR-20X with brightness of 2300 lumens and 2000:1 contrast ratio. I paid $1,000 for the projector.

Now I want an even bigger picture. So, I went out and bought myself an actual screen. The screen will hang from the ceiling and will roll up when not in use.

I have just purchased a Da-Lite 16ft wide by 12ft high movie screen.

I discovered that in order to get the picture to be 16 feet wide, I had to move the projector back further. Of course when I moved the projector back, it was not bright enough to my satisfaction. On really bright scenes, the picture was fine, but when darker scenes appeared....there was not enough contrast and the whole scene appeared dark.

I looked on the Projector Central website and found that in order to get a projector to throw an image that large with a longer throw distance, I would need a projector with an output of 6,000 lumens. Or, roughly three times the output of my current projector. Those projectors start at $6k to well over $20-30k. Waay out of my league.

I found a company that makes a wide-angle lens adaptor that will allow a shorter throw distance for a larger image. I asked the sales person what effect the adapted lens would have on the image. She told me that it could decrease the light output by 5 to 20 percent. The new lens would give me a 50% larger image from the same throw distance that I have now.

The room is 22ft wide and 70ft long with 22 ft ceilings. The screen will be suspended from the ceiling. The ceiling is concrete. The projector will be on the floor.

Please share your thoughts on all of this please.

Please click on my system page to see the room that the screen will be in. The screen will be against the wall where the window is. I am going to re-configure the whole room in order to accommodate viewing movies.

I am able to make the room pitch black. The window in the picture is the only source of sunlight.

Click here to see the conversion lens I am thinking about getting: CONVERSION LENS

Click here to see the screen that I have MY SCREEN

I will have the screen installed next week.

Click here to see MY ROOM and my system.

My home theater sound is a 5.1 configuration. I just can't imagine any more speakers than I have now in order to go 7.1 or 9.1.

I have tested the 16ft by 12 ft image on a beige painters drop cloth at the end of the room where the window is. I think I may be on to something...it looks promising. Sitting from 20 feet away from the screen, it is like sitting in an IMAX theater.

This room will serve as my living room and my 2 channel listening room. The screen and projector have to be put away when not in use. (well, the screen will roll up)

The big question mark is the conversion lens.

Worse case scenario is that the screen can be rolled down to a 12ft or 9ft height.
128x128mitch4t
Mitch4t: Congrats on the setup for going big, but I would recommend posting this on www.avsforum.com They will definitely be able to provide a ton more information.

Another thing that will help is painting the ceiling flat black from the projector to the screen as this will reduce reflections onto the screen. Since this is a shared room this might not be an option.

If you haven't received the screen, sometimes people will buy a higher gain screen that will reflect more light. Common screens are 1.0~1.3 gain (like your wall would be close to 1.0). I use a Vultec Silverstar which is rated at 4.5-6 gain which is awesome for dim projectors but it has to be a dark room or it picks up any type of surrounding light and reflects it on the screen.

Also if you have less than 200hrs on your LCD projector (DLP's don't typically suffer as much as LCD's), keep in mind that the bulb will get dimmer over time. Another thing to factor in.
you may want to go to a high gain screen . i used a 1.3 gain projector paint system and it looks better than the 120 inch da lite pearlesant i was using.
Hate to tell you that you are the lucky victim of the laws of optics - Given the same light source and lens, a bigger image will always be dimmer then a smaller one. (ie measure less lumens on the screen) While it is true that light falls off with distance, that is not what's happening here.

To measure the same brightness on a bigger image you need a bigger lamp and or a faster lens, and or a brighter screen. No way around it. Just like you will need more watts to achieve the same SPL in a bigger room.

The other thing that is going on is that every lens has a range. At x distance it
will project an image x size. Move it further back and the image gets bigger, closer and it gets smaller. This is why zooms are popular. The conversion lens you found is designed for a worst case scenario where there is enough height in the room to get a reasonably sized picture, but not enough depth to back up to throw it with the stock lens.

Also a wideangle adapter will quite probably not be as sharp as what you are used to - optics again - you are likely to notice curvature on the edges as well as the image being brighter in the middle then on the edges.

The right way to do it is to size the projector to provide a given lumen level at a specific image size, then find the right lens that can deliver that image from the desired projection distance. Of course a fast lens (low f stop) will deliver more of the light to the screen - sort of like a more efficient speaker will be louder with the same watts.

The other part of the equation is gain (reflectance) of the screen. The higher the gain, the narrower the viewing angle but the brighter the image for a given lumen output. Think of gain with light as something like gain with a cartridge - certain screens amplify it.

Did you buy the glass bead or the matte surface? This will be an important clue as to how bright the image will be - with a glass bead you will find its a whole lot brighter then your wall or your sheet.

So what to do?

Well one thing you could consider is cancelling the screen and paying the restocking fee. Then you can get some special paint - a bright white is good but you can get better stuff - and simply paint your wall. Just Google "screen paint" (Once you determine an optimum size you can put a nice frame around it or dress it up however you like.)

Then put the projector on a ladder and start backing up till you feel that you have reached the optimum compromise between brightness and size. Rehang the projector there.

Keep in mind that as the image gets bigger its also going to look progressively worse as the pixels become more and more apparent. This is a function of resolution. Based on a quick Google search your projector outputs an XGA picture - meaning 1024x768 pixels. Since the viewing distance (where you sit) will remain the same the image will appear progressively coarser as it gets bigger. Will you be sitting 20 feet away per your test? If not, you should sit at the actual viewing distance and see if you can live with the resolution.

The brighter image will be a lot punchier and more dramatic and by keeping the image size under control you will enjoy higher resolution for a more cinematic experience.

Then save your pennies for a better projector - one that can handle progressive scan or maybe even hi-def.

Sorry to be the messenger here - its why home theater guys get the big bux =) So you know, I spent thirty years designing and staging projection in everything from conference rooms to stadiums. this very basic advice is based on hard-earned experience...
I recommend you get a smaller screen and just sit closer.
Your perception will be the same.
....unless you need that much room because a ton of people are there enjoying the view at the same time. If that's the case.....invite ME to the party!!!
Best,
John