# Projection for an Outdoor Movie



## spiwak2005 (Jun 8, 2009)

Let me run through my setup and ask a couple questions:

1 - movie under a tent. The tent is HUGE because it is going to be for dinner and other activities and finally a movie at the end of the night. Tent is 40' x 100'. However, no can tell me height of the sides. Anyone have a guess as to what standard height might be?

2 - they have a retractable 10' x 12' screen they are "borrowing" from a classroom. Does that sound like an adequate size for an 80-100 person screening?

3 - can a screen that size be hung off a horizontal beam in a typical 40' x 100' rental tent? I know this borders on being a rigging question and yes I do have certified riggers/union crew that will do the actual hanging, but are these tents possibly strong enough to hold that or is this a definite no-no?

4 - they want me to use my Blu-ray player for this which I normally never allow out of my booth. Using a standard "classroom" style 2500-3000 lumens LCD projector (front projection), is there any benefit to using a Blu-ray player in this situation? The projector most likely only has VGA (I do have a Component to VGA cable that I normally use with this player) or standard Video inputs (no HDMI option). Plus, I won't be able to do 5.1 audio (just a single amp and 2 EV louspeakers). So am I justified in demanding they make do with a regular DVD player?

Any other suggestions about the setup?


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## aminorking (Jun 8, 2009)

1. I would imagine that you will be able to reach the top of the sides with out being on your tip toes. You may just need a step ladder (or chair) to reach the top of the sides.
2. On screen sizes the ratio that i am aware of it 6:1 for maximum distance:screensize. With your screen I calculate your distance as 93'. Could some one else provide a similar figure?
3. This depends on the marquee (this a purely UK term?). If it is a traditional marquee you may not have beams in the right direction i.e. there will be beams running down the centre of the tent, but not necessarily across. If it is a newer style "Clear-span" marquee then there will be regularly spaced beam running down and across the roof.
I do not want to breach ToS but you should remember that the marquee will have to be strong enough to stand up in strong winds and with rain and water on the canvas.
4. I would have thought that a Blu-Ray player would be overkill, but I am really not in a position to comment as I have not seen a comparison. Obviously however, I the projector has a resolution of 800x600 then you will probably see no difference at all.


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## NickJones (Jun 8, 2009)

Question 1 I have no idea, consider contacting the company they are hiring it from.

Question 2 it seems adequate but the larger the screen gets, the dimmer the projection will be, you may even be able to effectively project strait onto the walls of the tent, depending on the materials.

Question 3 the only time I use tents is when I go camping in dome tents, not ones this size, so I can't help you there. 

The answer for question 4 could be one of these it gives you 1080p. Depending on what the projector can handle.

Nick


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## museav (Jun 8, 2009)

1. Don't really know. This could definitely be important as you want the bottom of the screen to be high enough to not get too much interference from people seated in front of other viewers, etc. A related issue might be where and how you locate the projector.

2. First, 10'x12' is not a standard screen size, that would be 9'x12' or 10'x13'-4", so that could make a difference. This is also impacted by the format of the image being projected, if they want to project a 16:9 format image then the image itself would only be 6.75' high for a 12' wide screen. The 6:1 ratio for the distance from the screen to the most distant viewer is generally used for computer graphics, you can typically use 8:1 for video presentations and some people get away with even more. With a 100'x40' tent where the screen is located and the orientation of the audience to it, for example whether the screen is at one end or centered on one side and whether the audience fills the space, can make a big difference in this distance.

3. Not knowing the tent, I don't know for sure but based on the ones I've seen, I sort of doubt it. I certainly would not want to find out the hard way that it didn't!

4. Unless the projector has a DVI-D/I or HDMI input and supports HDCP, then some Blu-Ray players are going to force you to at best use the analog component output and 720p resolution. So there probably wouldn't be much advantage to it in that situation.

On the projector output, 2,500 to 3,000 lumens is going to be really pushing it for the nominal 12' wide screen noted. Chances are that your control of both the ambient lighting in the tent and of any external light sources will be limited. That combined with the screen size noted, the fact that a 16:9 image would use only 75% of the total projected image and a lamp of unknown life may make it a real struggle to get a bright enough image. But that all depends on people's expectations, something which concerns me more if they believe a Blu-Ray player is required to get the quality they want.


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## BillESC (Jun 8, 2009)

The screen you're considering is way too small IMHO.

We do an event every year in a 60 x 140' tent and project onto the ceiling of the tent achieving a 15 x 20 image. That's what you need.


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## Thefoxygranpa (Jun 8, 2009)

BillESC said:


> The screen you're considering is way too small IMHO.
> 
> We do an event every year in a 60 x 140' tent and project onto the ceiling of the tent achieving a 15 x 20 image. That's what you need.



Agreed to the screen size being too small. Also, I would check with the owner/rental company of the tent, as they may or may not want a screen being hung from the tent sides.


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## museav (Jun 9, 2009)

Just wanted to point out that a 100'x40' tent is less than one half the floor area of a 140'x60' tent. However, what really matters is not the tent size but the audience area and its relation to the screen. Using the 100'x40' dimensions, having the screen at one end could make it over 100' to the furthest viewer but put the screen centered on one side of the tent and the furthest viewer is less than 69' away. Also, 80-100 people in theater style seating could fit in a fraction of the overall area while banquet style seating may require a much larger area for the same number of viewers.

With what we do know it may have to be looked at from the other direction. Given a 12' wide screen, that is a 6.75' high 16:9 image and thus a 54' recommended maximum viewing distance for video. If you went with a 4:3 image then it would be 9' high with a 72' recommended maximum viewing distance. Also, assuming the projector is a native 4:3 format such as 1024x768, then a 2,500 to 3,000 lumen projector would be a maximum of 23 to 28 ftL on a 12' wide screen, likely less unless the projector lamp is new. We don't know the screen gain in order to calculate the light off the screen but those are pretty low values unless you can really control the ambient light hitting the screen, but I'd typically be looking for maybe twice that. A 1024x768 projector displaying a 16:9 format image would also be a 1024x576 resolution, so any thoughts of 720p resolution or anything like that would be out, that would require a projector with a minimum 1280 pixel horizontal resolution.


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## spiwak2005 (Jun 9, 2009)

Thanks for the input. Just a couple more details for clarification...

It is 80-100 people theater style seating - only using a small portion of the tent. I probably have to put the screen along the 100' side and have 40' deep for the seating.

Ambient lighting will be minimal - the movie's at 9pm and all tent lights will be out at that time.

Lamp in the projector is probably less than 50 hours - I changed 4 of them this semester so I have several to choose from.


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## NickJones (Jun 9, 2009)

The smaller the screen the better it will look, but harder to see.
The less light the better.
Make sure you pick the lamp that is the newest and least used. You don't want it to blow mid movie.
Nick


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## len (Jun 10, 2009)

spiwak2005 said:


> Let me run through my setup and ask a couple questions:
> 
> 1 - movie under a tent. The tent is HUGE because it is going to be for dinner and other activities and finally a movie at the end of the night. Tent is 40' x 100'. However, no can tell me height of the sides. Anyone have a guess as to what standard height might be?



Most tents are 8' side walls. 


spiwak2005 said:


> 2 - they have a retractable 10' x 12' screen they are "borrowing" from a classroom. Does that sound like an adequate size for an 80-100 person screening?



I would think so. If you can get the bottom of it 2 - 3' off the ground, even better.


spiwak2005 said:


> 3 - can a screen that size be hung off a horizontal beam in a typical 40' x 100' rental tent? I know this borders on being a rigging question and yes I do have certified riggers/union crew that will do the actual hanging, but are these tents possibly strong enough to hold that or is this a definite no-no?



I've mounted truss off two tent poles. A movie screen will be fine. BUT YOU BETTER MAKE SURE QUALIFIED PEOPLE ARE DOING IT.


spiwak2005 said:


> 4 - they want me to use my Blu-ray player for this which I normally never allow out of my booth. Using a standard "classroom" style 2500-3000 lumens LCD projector (front projection), is there any benefit to using a Blu-ray player in this situation? The projector most likely only has VGA (I do have a Component to VGA cable that I normally use with this player) or standard Video inputs (no HDMI option). Plus, I won't be able to do 5.1 audio (just a single amp and 2 EV louspeakers). So am I justified in demanding they make do with a regular DVD player?


The chain is only as good as the weakest link. So if you can get better this or that, do it. 
Doesn't the media dictate what type of player is required? If it's a blu-ray disc, a standard dvd player won't do any good. And if it's a dvd, I doubt a blu-ray player will be noticeably better quality regardless.


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## jongaduet (Jun 11, 2009)

yeah with that projector, blu ray won't do you no good, but it will still play standard dvd too. imho you need a brighter projector BADLY!!!


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## ruinexplorer (Jun 12, 2009)

Unless you have a projector with a native resolution that falls within the realms of HD as well as the ability to connect with the proper digital cables, you can feel justified in not using your Blu-ray player. As has been stated, you always need to plan for your weakest link. With the projector that you have stated that you will be using, you will not be able to project HD. Whatever you send it will be downconverted to the native resolution of the projector. 

Also, I agree that you may want to consider a different projector. With that large of a screen, your image will be relatively dim and you will need considerable control over ambient light levels. I would recommend something at least in the 5000 lumen range. Of course it depends on your content. If you are watching something that is generally bright all the way through, you might be able to get by. On the other hand, if you are watching something dark (horror movies, or something like that), you will likely be very disappointed in your projectors performance.


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## museav (Jun 12, 2009)

len said:


> I would think so. If you can get the bottom of it 2 - 3' off the ground, even better.


In orde to avoid having the image blocked by those sitting in front of other viewers, it is typical to try to have the bottom of the image around 4' above the floor/ground with a minimum of 3'. The seating arrangement can also affect this, if the seating can be staggered such that any viewer is looking between those seated directly in front of them then that can help, but if the seats are all nicely lined up then it is even more important to get the image higher. Also keep in mind that with front projection you need a clear path from the projector to all of the screen, or at least the image area on the screen, so unless you can get the projector up high or have a large projection path cleared through the vieweing area, you may need to have the screen a bit higher so that you're not shooting through people's heads.


len said:


> I've mounted truss off two tent poles. A movie screen will be fine. BUT YOU BETTER MAKE SURE QUALIFIED PEOPLE ARE DOING IT.


I took it that the original question was about hanging the screen directly off a horizontal support that is part of the tent structure, which would likely be quite different than hanging off a truss or other dedicated support element rigged between two poles. 


len said:


> The chain is only as good as the weakest link. So if you can get better this or that, do it.


I would normally agree with this but I doubt that even a standard DVD player with a DVI or analog component output would be the weak link in this case. In fact the idea of starting with the best can work against you in this type of situation as at some point the video signal has to be scaled to match the projector's native resolution and the more processing required to do that the more negative impact it may have on the result. While projectors can usually handle higher resolution signals than their native resolution, using a higher resolution source can actually negatively impact the result.


len said:


> Doesn't the media dictate what type of player is required?


That's a very good point. If they have a Blu-Ray disc then their request makes sense but otherwise I don't see any practical benefit to it in this application.


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## len (Jun 12, 2009)

museav said:


> I took it that the original question was about hanging the screen directly off a horizontal support that is part of the tent structure, which would likely be quite different than hanging off a truss or other dedicated support element rigged between two poles.



Could be. But assuming the tent wall is 8' high, no 9' + tall screen would fit. The only way then would be to stand the screen up away from the wall. I was thinking attaching it between two poles in the tent. Or if it's a clear span, hanging it from the roof beams. Or just ground supporting it. Too many unknowns to really say what the best way is, however. Depending on the formality of the event it might just be easier to show it on the tent roof.


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## museav (Jun 12, 2009)

spiwak2005 said:


> 2 - they have a retractable 10' x 12' screen they are "borrowing" from a classroom. Does that sound like an adequate size for an 80-100 person screening?
> 
> 3 - can a screen that size be hung off a horizontal beam in a typical 40' x 100' rental tent? I know this borders on being a rigging question and yes I do have certified riggers/union crew that will do the actual hanging, but are these tents possibly strong enough to hold that or is this a definite no-no?


I don't know if "retractable" means electrically operated or manual, but since dealing with power for a screen has not been mentioned, I assume it is a a manual, pull down screen. A 9'x12' screen may weigh around 80 lbs and that load would be spread over at least two hang points, but there would be additional load imposed when you go to pull the screen down and that load may not be evenly applied and may not be purely vertical, it could also apply some torque. So unless you have a solid hang, you probably need to be careful when you do pull down the screen. As Len said, too many unknowns regarding the screen and tent to really say.

What I can find online indicates that 40' x 100' tents are available as eiter frame tents or pole tents, although for that size pole tents seem much more common. A typical 40' x 100' pole tent would have a 7' wall height and four 17' to 24' high poles spaced every 20' down the center of the 100' length. A typical 100'x40' frame tent would have 8' walls and around an 18' center height. Both seem to be available with up to 10' high side walls but as an optional extension and not as a standard configuration. So Len's comment on the height is a very good point, between the limits the tent may impose on the height and the projector brightness, you may be best off to go with a smaller image and not try to fill the screen. If the screen is on a wall, you use theatre seating and you want everyone to see all of the screen, then you might be limited to a 3' to 4' high image, which should work much better with your projector but might be a little small depending on the media displayed.


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