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Title: Large Screen Video
Post by: Bob Cap on December 14, 2005, 06:09:38 PM
Anybody here into large screen video projection?

I have a Church that we are putting a sound system into that is now interested in a large screen (16' wide x 12' high) video projection system.

The quirk is the projector has to be at the back of the church, 60 feet away.

Any suggestions? Any web sites to look at for calculating the size of projector needed?

Thanks

Bob Cap
Title: Re: Large Screen Video
Post by: Aaron McQueen on December 15, 2005, 11:25:41 AM
To shoot from that far away you will probably need a long throw lens.  Also you will probably need a brighter projector than if the projector is mounted closer to the screen.  Find a good local AV retailer(not Best Buy) and ask them to demo the projector before you buy (good retailers have no problem doing this).  This way you can make sure it will reach your screen and have the necessary brightness.  I tried 4 projectors before I found the one we liked.

Also make sure you use a dual monitor setup. Monitor 1: preview and desktop, Monitor 2: projector.  Also get some good worship software like EasyWorship for projecting the words.  Despite what people may say Powerpoint is not the best tool for worship worship.
Title: Re: Large Screen Video
Post by: Micheal Martinez on December 15, 2005, 05:28:42 PM
Bob,
I found a web site at one time that had a projector calculator on it, however I don,t remember which one it was. I think a Google search would find it pretty easily.
If you are interested my church has a 16x16' motorized remote controlled screen which has never been used and is still in the box, we would love to be able to help out another church who might need one. Let me know maybe we could work something out.

Mike
Title: Re: Large Screen Video
Post by: Brian Kent Tennyson on December 16, 2005, 11:33:23 AM
OK. Few observations, calculations and reeudcations (is that a word).

Observation. 16X12 is a standard format screen. no one should be putting these in anymore, the world is moving rapidly to wide format. Plus four line hymn phrasing lays out better on a 16:9.

Calculation. Determine your screen height by dividing the distance from the screen to the back of the room by 6 (if you are using it for small text and spreadsheets) or 10 to 12 (if you are using it for video or as a replacement hymnal). I will assume that 60 feet is the distance to the worst seat so that would give us a screen height of 6'. screen size of 6'h by 10'8"w.

To determine the lens throw ratio, divide the distance from the lens to the screen by the width of the screen. if your width is 10.68' and distance is 60' you will need a 5.6:1 lens.

Reeducations (there it is again). Distance from the screen has no effect on the amount of candlepower you will need from your projector. ANSI lumen requirements are the product of a calculation of the gain of the screen, ambient light and desired contrast. Less stray light on the screen = less light needed out of the projector.

Photons are not like sound waves, and are not noticeably affected by 60' of "clear" air. If light control is good just buy the brightest thing you can afford and you should be alright.

If you can take a light measurement of the vertical surface that the screen will be on I can do the calculation for the required brightness of the screen.
Title: Re: Large Screen Video
Post by: Brian Kent Tennyson on December 16, 2005, 11:35:16 AM
Also, Christie Digital www.christiedigital.com has a try it before you buy it program. It's worthy of checking out.
Title: Re: Large Screen Video
Post by: Aaron McQueen on December 16, 2005, 01:11:07 PM
Quote:

Reeducations (there it is again). Distance from the screen has no effect on the amount of candlepower you will need from your projector. ANSI lumen requirements are the product of a calculation of the gain of the screen, ambient light and desired contrast. Less stray light on the screen = less light needed out of the projector.


Sorry for my lack of edumication.
Title: Re: Large Screen Video
Post by: Brian Kent Tennyson on December 17, 2005, 05:11:38 PM
Well you're in good company, it's a very common miconception, especialy among sound system designers.
Title: Re: Large Screen Video
Post by: h.s.overman on December 30, 2005, 12:08:31 AM
Just as a benchmark so that you will know that it can be done, our church is using a Mitsubishi 5950 (4700 lumens I think)with a long throw lens to get a 10 foot wide image at 65 feet in fairly strong ambient light.  Room darkening is very helpful, though, when doing full video or tv type signal.  (We use the system for the men's group superbowl party each year.)  For regular worship we use a dual monitor set-up with one monitor that displays the projected image.
Title: Re: Large Screen Video
Post by: Kent Clasen on January 10, 2006, 09:38:06 AM
Hi Brian!

Are there higher power/lower cost 16:9 native projectors available now, or are you resizing native 4:3 projectors?  Is there a decrease in quality in using 16:9 mode on a native 4:3 projector?

Thanks for the info.
Title: Re: Large Screen Video
Post by: Jon Bannan on January 11, 2006, 10:15:07 PM
Bob,

We are using a large 17x23 (I think that is the dimension) screen for our services and special events.  Our projector is currently located roughly 110-115ft in the back of our sanctuary.  We are using an Eiki 6500 lumen with a long throw lense successfully but as Bryan says light control is a huge factor.  We tend to keep our side blinds shut to cut out ambient cross light which helps tremendously.  We are using a 4:3 ratio.  Let me know if you have any questions.
Title: Re: Large Screen Video
Post by: StJohn Gill II on January 13, 2006, 07:07:39 AM
We have a 3 screen set-up at church with 2 video mixers and 4 cameras. 16:9 is cool but if you are on a budget fairly unrealistic. all our stuff is still 4:3 even though the cameras are all capable of HD 16:9. Anyway, most stuff is still in 4:3. for HOW stuff i think 4:3 is still better because you have more room above words for camera image if that is what you are going to do or may want to get into in the future. If the projection system is only for words, you might as well save some money and stay in 4:3 anyway.

How big is your church? Chances are that a 16x12 screen with a widescreen video in the middle will be fine on the odd occasion anyways.

Easiest way to work out what lens you need. Most lenses  will come with a zoom factor like 3-5 or so. What this means is that the lens will focus and zoom to the size if the screen from a distance of 3 to 5 times the width of the screen. Pretty easy. i.e your projection point is 3.75 times as far away from the screen as the screen is wide, so a 3-5 lens will do you just fine.

To work out brightness: it depends on a lot of things. The way i buy a new projector is to ring up a couple of companies, mark out the size of the screen if i dont have the screen and get them to bring projectors with the right zoom from about $500 below my "budget" to about $1000 above my "budget' and see if i can get one of the "too expensive" ones into my price bracket. Never failed yet!!!! Also, sometimes the cheaper ones will bring a brghter image at a lower quality that may not even be a problem with your set-up, it has happened at a couple of installs i've been helping people out with. Anwyay, just try a few and work out what you want - just make sure you have all the stage lighting that could throw onto the acreen on if possible when testing to make sure you get an accurate representation of what is going on.
Title: Re: Large Screen Video
Post by: Brian Kent Tennyson on January 13, 2006, 12:32:57 PM
Kent Clasen wrote on Tue, 10 January 2006 08:38

Hi Brian!

Are there higher power/lower cost 16:9 native projectors available now, or are you resizing native 4:3 projectors?  Is there a decrease in quality in using 16:9 mode on a native 4:3 projector?

Thanks for the info.


Christie has the LW40U 4500 ANSI for around $10,000. They also have the LW25U with 2200 ANSI for around $6,000. Both are OEM products from Sanyo so they are basically the same. The PLV-WF10 and the PLV-80 respectively.
Title: Re: Large Screen Video
Post by: Kevin Maxwell AKA TheMAXX on January 14, 2006, 01:01:08 PM
I don’t remember where I found this but a standard television (tube type) is equal to 45-foot lumens. So if you want your screen to be equal to a TV you divide the projector lumens by the square footage of the screen. So if you have a 9-foot by 12-foot screen, that is equal to 108 square feet. If the projector output is 5000 lumens then take that number and divide it by the 108 and you get about 46.3 foot lumens, just a tiny bit brighter then a standard TV. Now this doesn’t take into account the type of screen used. If you have a high gain screen it will be a bit different and should be able to be calculated. But the real killer is how much light is hitting the screen. Whatever is brightest wins.

I hope this is of some help.  
Title: Re: Large Screen Video
Post by: Roy Richards on February 07, 2006, 09:32:21 PM
I have a Christie DS30 at work that developed a problem requiring factory service, it took 4 weeks to get it back. It was only 18 months old, but they said it was already discontinued so they could not expedite.

Brian, what kind of support have you had from Christie? I have been less than impressed, as they will only deal with the vendor I purchased the unit through. I prefer to cut the vendor out of the equation once I own the item.
Title: Re: Large Screen Video
Post by: Brian Kent Tennyson on February 08, 2006, 11:25:42 AM
All of my support issues have been delt with through the vendor. Since Christie protects their line (you can't buy it at a knocked off price from an internet dealer in North Dakota) their whole system is probably set up to serve their vendors. I have found that most of the more reputable vendors have protected lines, it keeps much tighter control over what clients are promised, how service is handled and who is trained to handle field service.

Of course, on any forum, we will find exceptions to every rule, good or bad. I'm sure Christie's service satisfaction isn't 100%. Nor do I have any vested interest in Christie as a company.

My suggestion, to anyone who cares, is to find a good vendor and let them do the dirty work on warranty. You pay a higher price for a Christie projector, or Wolfvision Doc Camera or Bi-Amp audio processor, but a lot of what you are paying for is service from you vendor, don't be afraid to rely on them for service.

My three issues have been with out of box or during installation, and they may have been delt with quicker because I'm a consultant (I never really thought about it that way before), one issue was fan noise, they replaced the unit, one issue was color matching with two other LCD projectors, they replaced the unit and one was from me pushing the lens adjustment beyond the acceptable range in a 10k Rodie and damaging the light engine, they flew a guy out and replace the light engine the next day and apologised to me for not making the instruction manual more clear.

I have contractors that swear by Eiki (i don't like their processing) Some that love NEC. I just looked at a $3000 3500ANSI single chip DLP form Optoma yesterday that looked awesome.

Anyway, I would give your vendor a chance, you might get farther that way.
Title: Re: Large Screen Video
Post by: David Hadfield on February 09, 2006, 04:57:17 AM
We are currently running 2 16x12 rear projection screens using NEC MT1050 2100 lumen LCD projectors. We paid $10,000 (Aus) each for them 4 years back and are looking to upgrade to 16x9 format. We upgraded our camera system in July to Sony cameras (SD) and have been running 16x9 on the 4x3 screens. This photo gives you an idea of how it looks and/or will look when we make our existing screens wider (front projected with Mitsubishi 3900 lumen proj.)

index.php/fa/4009/0/

We are looking at getting the brightest projector we can for the best price and will still go rear projection as it works better for us - the only problem is the extra expense of short throw lenses as to get the width we would lose to much space backstage (looking at $16,000 Aus, each for NEC 6000 lumens with lens). We blank out the area so no ambient light gets onto the back of the screen. Going front projection wouldn't work for us with our current PA - but even a new PA (hopefully sooner than later, line array???) wouldn't allow such. We also use smoke regularly which would impede the front option.

I have also found that as far as auto screens, 4x3 is far cheaper than 16x9 (like half the cost) and you can still do 16x9 just without a pretty black border.

We use a local (Aus) product called Presenter for word overlays and have found it to be easy to use and almost fool proof.


Title: Re: Large Screen Video
Post by: Roy Richards on February 09, 2006, 02:29:58 PM
Interesting that Powerpoint was originally called Presenter before Microsoft bought it. Wonder if the Aus version is related.
Title: Re: Large Screen Video
Post by: Roy Richards on February 09, 2006, 02:37:29 PM
Have you checked into using a mirror or two to increase your distance? I have a system at work that fills an 8 foot wide screen rear projected in a 36 inch deep case that uses two mirrors to bounce the signal making the depth 3 times actual. Works nicely.
Title: Re: Large Screen Video
Post by: Brian Kent Tennyson on February 09, 2006, 05:58:33 PM
Also, beware of anything below a 1.3 lens as you will start to get a hot spot in the middle of your image.
Title: Re: Large Screen Video
Post by: David Hadfield on February 10, 2006, 12:14:32 AM
Interesting that Powerpoint was originally called Presenter before Microsoft bought it. Wonder if the Aus version is related. Roy Richards NRBC Media


I think you will find it is somewhat different - made specifically for churches. Have a look

http://www.discoverysystems.com.au/presenter/default.htm

We haven't used/seen any of the other stuff available but this works well for us.
Title: Re: Large Screen Video
Post by: Hansel Anasarias on May 31, 2006, 12:58:45 AM
??? are there any online stores that show the cost of these kind of products.  my church is in the process of planning a permanent install.  right now we have a dell computer and projector on a cart, and it's getting really annoying.  we're eventually using Song Show.  thanks.
-Hansel