# How far will a projector reach?



## MillburyAuditorium (Sep 22, 2009)

Hello everyone,

Well, I can just go try it in person, but figured I would ask first.

Well for a thing our town has "The Chain of Lights", one of the towns clubs want to have a couple movies in our theatre, so I am transforming our theatre into a movie theater for a day, and so, I will be simply bringing my own laptop (Not even going to try to do it on the doggy school computers xD) and find the media cart key and remove the projector from it. (  I'll put it right back where I found it) and set it up in the real of the theatre where the sound board is, so I can hookup the laptop to the board and what not. 

Anyways, my question.
The other techy can't make it that day, so im left alone, and I was wondering if the projection will make it to our theatre's built in projection screen on stage, or will the picture be lost. I dont know anything about how projectors work, will it just work from wherever? Mind you the lights will be off. 

If it doesnt reach, I need to get some I REALLY trust, and either a 100 foor video cable, or 100 foor 1/4 inch audio wire...


----------



## ScottT (Sep 22, 2009)

First thing:
What is the distance from the projector to the screen?

If it's one of the crappy little ones that are used in classrooms then it will not go further then ~20 feet. However you can use an online calculator such as this one (Projection Calculator Classic - Throw Distance and Screen Size) to find out the necessary information.


----------



## ruinexplorer (Sep 22, 2009)

My first guess is that you won't be happy with your image (based off of your earlier posts about your theater). Most likely you have a small desktop projector that may have upwards of 3000 lumens. I don't know how large of a screen that you have, but my guess is that the zoom lens (most likely not one that you can change) will not be capable of throwing the distance that you need (your image from back of house will be larger than your screen). Again, the more you can tell us, the more we can help you. If you can find it, get the model of your projector, the distance from where you want it to the screen, and the size of your screen. Most projector manufacturers will have a distance calculator on their website. This will help you figure a lot of this out yourself.


----------



## MillburyAuditorium (Sep 22, 2009)

Well its not the cheapest projector, but not the best. It does have controls to move and re size the image, and does have a lens to adjust the size of the image. It is a pretty big screen, almost spanning the entire length of the stage opening, and almost touching the floor to the top of the proscenium arch. I'll try finding the model of the projector. 

If it just doesn't work, I am sure we could rent a professional one for the day.


----------



## ruinexplorer (Sep 22, 2009)

If you have an installed screen, what projector do you usually use? A good rental could set you back $1000/day very easily. I'd rather try to help you use what you have, especially since you are trying to save money for your other project.


----------



## fredthe (Sep 23, 2009)

In a dark room, you may be OK with your small projector, but it's likely you won't be able to put it at the back of the house, you'll need to move it closer. As was mentioned, check the manufacturer's website for a calculator, or the best way is to just give it a try. Also, don't think that you necessairaly have to fill the screen; a smaller, brighter image is better than a big, washed out image.

Best to have your laptop with the projector. Computer video can degrade over long runs if not done right, but audio can easily and cheaply be run to your mixer. Remember, you can also control the volume from your laptop, and once set (pre-show) you shouldn't have to change it.

If you do need an assistant, consider putting them on the computer... then you can worry about sound and (house) lights.

-Fred


----------



## MillburyAuditorium (Sep 23, 2009)

We do have an installed screen, but no installed projector, would be great if we did :/ We just use a media carts projector, but it is usually down in front of the stage. 
Didn't realize a rental would cost that much : P 
Well, I suppose if when I try it out in person it doesn't work I will try making the image smaller like Fred said, and if that is to no avail, maybe have the projector in the some middle of the middle rows. I can use an S-Video cable if image stays better over longer reaches? I know I could get a S-Video cable, all the classrooms have them to go to their TVs.

As for sound im not worried, one of the boards channels is reserved for non perminant inputs, like, our iPods 

Well guess I will have to hope for the best ^^


----------



## SHARYNF (Sep 23, 2009)

the 1000 dollar a day projector is definitely a high end model, probably a lot more complex than what you are looking for


Basically it will come down to size of the image, It does not have to totally fill the screen. Controlling the ambient light in the room is essential. In our local movie theater we now are using a 2 to 3000l lumen projector to display ads before the show. the screen is 35 feet wide projector is 70 feet back and it works reasonably well. For some film festivals we used a different projector 2000 lumens about 50 feet back and that was acceptable also


You don't always need a Christie ;-)))

Basically control your ambient light, and move the projector around to get the best quality image with a reasonable size. Better to have a brighter and clearer image that is smaller than a huge image that is very dim and washed out

Sharyn


----------



## MillburyAuditorium (Sep 23, 2009)

Thank you sharyn : )

As for ambient lighting, all lights would be off, so, that should be fine.

Great, our screen is fairly large, so can definitely make the picture smaller. Hoping for the best ^^


----------



## ruinexplorer (Sep 23, 2009)

There's a difference between a 2-3k lumen projector showing ads which are generally brighter and needing less contrast than the average movie. A midline projector at around 4000 lumens (most likely a step up from what you have in stock) will still run you around $700/day (cheaper by weekly rental) one similar to whay you most likely have would run around $400/day. Like I said, we can probably work it out with what you have and save your money for your other project and prices may vary in your area. 

Another thing to consider is the sound from your laptop. If you haven't used it connected to your system before, try it out first. Many (not all) laptops have a noise problem with their power supplies and you need to verify it.


----------



## fredthe (Sep 23, 2009)

MillburyAuditorium said:


> I can use an S-Video cable if image stays better over longer reaches? I know I could get a S-Video cable, all the classrooms have them to go to their TVs.


S-video will work in a pinch, but won't be as good a signal. Stick with S/XVGA (whatever the projector supports) if at all possible.

-Fred


----------



## MillburyAuditorium (Sep 23, 2009)

Yeah, we arent planning on spending money on this besides the movies, So I can work with what I have, I am sure we will be fine : )

And as for noise problems,
I have a little DJ setup in my house, and I do get this noise problem while the power supply is plugged in, its so weird, anyone know why it does this? Gives a hum through the speakers.

I have resolved this issue by plugging the laptop into a different outlet, but still on the same circuit.
: ) Should work at the school as well, will try it out.


----------



## MillburyAuditorium (Sep 23, 2009)

fredthe said:


> S-video will work in a pinch, but won't be as good a signal. Stick with S/XVGA (whatever the projector supports) if at all possible.
> 
> -Fred



Oh, okay, for some reason I though S-Video quality would be better.

Well, the projector has like, every every input you can imagine. Even audio inputs? Never did figure that one out.
And my laptop has S-Video, the standard blue connector (Don't know the name), and tan. (Don't know the name.)


----------



## ruinexplorer (Sep 23, 2009)

MillburyAuditorium said:


> Oh, okay, for some reason I though S-Video quality would be better.
> 
> Well, the projector has like, every every input you can imagine. Even audio inputs? Never did figure that one out.
> And my laptop has S-Video, the standard blue connector (Don't know the name), and tan. (Don't know the name.)



The blue one will be commonly known as the VGA connection (D-sub 15) and the tan one will be your DVI connection. DVI will have variations depending on the ability to accept analog, digital, or both. On my laptop, the DVI is digital only and I cannot use a cable that will accept analog signals as well (you will know by the four little holes/pins surrounding the blade connection, if they aren't there then you have digital only). 

As for the noise from your laptop, that is a grounding issue. Generally you want all of your audio on the same power to avoid this noise. It sounds like you may be lucky that you can work it that way. I have used other computers where I need to have a Direct Input box between my laptop and the mixer to avoid that noise. Simalarly, the best way to avoid video "hum bars" is to have all of your video on the same power.


----------



## SHARYNF (Sep 24, 2009)

ruinexplorer said:


> There's a difference between a 2-3k lumen projector showing ads which are generally brighter and needing less contrast than the average movie. A midline projector at around 4000 lumens (most likely a step up from what you have in stock) will still run you around $700/day (cheaper by weekly rental) one similar to whay you most likely have would run around $400/day. Like I said, we can probably work it out with what you have and save your money for your other project and prices may vary in your area.
> 
> Another thing to consider is the sound from your laptop. If you haven't used it connected to your system before, try it out first. Many (not all) laptops have a noise problem with their power supplies and you need to verify it.



I guess we will have to agree to disagree
The ads we are running are infact video clips, and we have run some film festivals again using projectors in the 2-3k region. is it perfect no but with ambient light very low it does work especially if you keep the image size to around 20 feet diagonal. It is worth a try. for our huge screen that is about 50 feet wide we do use a Christie 12k

Personally I would NOT run it from a pc, all the up and down converting etc etc does not help. I would get a dvd player, one with Progressive scan output and use Svideo to make the short run from the DVD player to the projector. Send your audio to the booth. 

Again your milage may vary, but try it. Get your projector on the cart and see how it looks and the size of the image and the quality. Most low budget productions don't have it available for 400-800 dollar per day projector rentals. 
While a huge screen is nice and impressive but scaling down can work

Sharyn


----------



## MillburyAuditorium (Sep 24, 2009)

Thanks ruin ^^

Well, I would like to use the laptop because I could just control it a bit better.
Either way, if I can get the projector to work good from the back of the house where the control "center" is, then all connections will be within 2-4 feet. 

One video cable out of the laptop to projector right next to me on a stand/cart.

And one audio cable out of the laptop to the sound board.

I will bring the laptop and charger I would be using in advanced to make sure I can get a way to stop the hum if there is any.
It is a problem in the outlets is it not? Or is it in the battery system in the laptop? Because if I simply put the laptop on a different outlet noise goes away, as I said.


----------



## fredthe (Sep 24, 2009)

On the hum: It's likely an issue with how the grounds on the outlets are wired. (I'm assuming your laptop charger has a ground connection)

On brightness: I came accross this bit of information (though I haven't verified it): The SMPTE standard for projection brightness is 16 footlamberts, with a range of 12 to 22 fL. Now, you just need to get out your calculator and optics handbook 

As a bonus question, what's intersting about the footlambert as a unit of measurement?

-Fred


----------



## ruinexplorer (Sep 24, 2009)

SHARYNF said:


> I guess we will have to agree to disagree
> The ads we are running are infact video clips, and we have run some film festivals again using projectors in the 2-3k region. is it perfect no but with ambient light very low it does work especially if you keep the image size to around 20 feet diagonal. It is worth a try. for our huge screen that is about 50 feet wide we do use a Christie 12k
> 
> Personally I would NOT run it from a pc, all the up and down converting etc etc does not help. I would get a dvd player, one with Progressive scan output and use Svideo to make the short run from the DVD player to the projector. Send your audio to the booth.
> ...



You can say that we are agreeing to disagree, but the point that I was trying to get across is that we have many unknown variables here. The setup in a movie theater can be quite different from a traditional theater. First of all, a movie theater usually will have a higher gain screen due to a more direct viewing area, especially in the theaters with smaller screens. As you saw, I have made an assumption as to the brightness of Mill's projector. We don't know how bright it is. Since we are working with unknowns, I definitely support your idea of trying it out with what they have. I also agree that a DVD player (though I'd recommend component to S-video) is a better solution. 

Oh, Fred, could you maybe reword your question and post it to the Question of the Day forum?


----------



## museav (Sep 24, 2009)

I agree that there are too many unknowns, although there shouldn't have to be so many. If the screen and projector are existing then getting the actual screen size and projector model should be possible. And the ambient light level probably could be measured. Of course that still leaves factors such as the loss through the lens, loss due to lamp age, screen material, etc. unknown.

Keep in mind that a composite or S-Video out of a computer and then displayed on a large screen may not look that great. Also consider that if you have a native 4:3 format projector and show widescreen 16:9 movies then you are using only 75% of the total image area the projector displays for the actual image and thus also only 75% of the projector's total output.

Last, I always cringe when I hear about "movie nights" as people too often do not consider the related rights and Intellectual Property issues. Make sure these are covered, don't put the school in a position of liability for their presenting any copyrighted material without appropriate rights or permission.


----------



## Lotos (Sep 25, 2009)

museav said:


> Last, I always cringe when I hear about "movie nights" as people too often do not consider the related rights and Intellectual Property issues. Make sure these are covered, don't put the school in a position of liability for their presenting any copyrighted material without appropriate rights or permission.


 
Ditto... I'm surprised it hasn't come up sooner.

This is what qualifies as a 'Public Exhibition'... You know, the things those lovely blue warning messages say that you can't do.

Check here for a good resource: Motion Picture Association of America


----------



## SHARYNF (Sep 25, 2009)

Here is a link Annual License to Show Multiple Movies | Public Performance Site License | School Movie Night

There is some latitude for showing movies in a "Classroom type setting with a teacher present etc" that allow for an ability to show them

I have seen schools set up a class (no one says how big or small the class needs to be) assign a teacher to be there, set up a general curriculum ie "Cinema as an art form in our digital society" and hold a pre/ post showing discussion... all perfectly legal with no license required as long as all attendees are members of the class.



Sharyn


----------



## museav (Sep 25, 2009)

Sharyn,

What really concerned me was the comment "Well for a thing our town has "The Chain of Lights", one of the towns clubs want to have a couple movies in our theatre, so I am transforming our theatre into a movie theater for a day...". That does not sound at all like an educational application and much more like entertainment or fund raising. If the "movies" are original content those groups produced themselves then that is one thing, however since the school is apparently providing the venue, equipment and operator they could definitely be the party liable if there are any problems.

I also want to go back to the brightness issue. With movies, between the actual image format, losses from a long throw lens, reduction in output due to lamp age, etc., you could have an effective brightness on the screen that is well below what you might get with an image matching the native projector format, a standard lens and a new lamp. The actual media or content will also be a factor. I believe that the 16ftL level mentioned for the SMPTE standard is for film projection, the digital cinema standards actually allow for a slightly lower image brightness. However, those criteria are addressing the actual brightness reflected off the screen and they tlso identify very low ambient light levels in order to maintain good image contrast at that brightness. By the time you factor in any optical and other losses and the actual ambient light levels found in many venues, in order to get the desired result you typically need much more projector output than you would calculate based solely on the 16ftL number and the screen size.


----------



## MillburyAuditorium (Sep 25, 2009)

Well, I will be getting the projector model and everything, and trying it in person, I was simply wondering if a standard school quality projector would have good enough quality to be shown from the rear of the house. Will probably make the image smaller for better quality. All lights will be off, and there is no windows, etc, in the theatre, if thats what you meen by ambient light.



As for copyright and what not, I have been told they will not be charging to get it, so its free. Thats legal right? If you don't charge to get in, and buy the DVD?


As for eduational,
It is not during school hours, weekend, and the school lets the town use the gym for a little, market type place, so if any group wants to book the auditroium, they are free to do so. I am thinking there want be many people there anyways : P


----------



## fredthe (Sep 25, 2009)

MillburyAuditorium said:


> As for copyright and what not, I have been told they will not be charging to get it, so its free. Thats legal right? If you don't charge to get in, and buy the DVD?


 Unfortunately, no. This is a common misconception with copyright, just because you aren't charging for it doesn't make it legal. A DVD you buy at the store is licensed for home use, showing it to an audience in a theater is not covered. Now, the fact that you are not charging admission may reduce the cost of the license, but it doesn't eliminate the need.

Think of it this way... don't you think that Disney would get upset if you were producing High School Musical without their permission, even though you weren't charging admission?

-Fred


----------



## fredthe (Sep 25, 2009)

MillburyAuditorium said:


> I was simply wondering if a standard school quality projector would have good enough quality to be shown from the rear of the house.


Back when we still had 16mm films in schools, projectors were pretty "standard" (most schools had Bell & Howell projectors )

With video projectors, there is a wide range in brightness and quality, and with technology getting better and cheaper, a projector bought last year will likely be better than one bought 5 years ago. So, tell us the model, and go try it out.

-Fred


----------



## ruinexplorer (Sep 25, 2009)

Search this forum as we have discussed public viewing of films as an option for fund raising. One of the most often used services for film release (provide the DVD as well as the rights to show it) is through Swank:Public Performance License | Obtain a Public Performance License to Show Movies Legally. 
There are very few ways to publicly show copywrited material that does not involve a fee. That includes public showings of sporting events as well as television shows, not just movies.


----------



## museav (Sep 26, 2009)

If you read the FAQs on the site that Sharyn and ruinexplorer referenced you will find that the Public Performance license they do offer for K-12 institutions requires that no admission fee be charged other than to cover costs, if you did charge admission then there would be a different license required.

The type of use noted has several aspects that require some form of license to be obtained. For one, it is a public performance, it is not limited to members of any specific group or organization. For another, it is not academic in nature as it is not part of a class setting nor related to a core curriculum. The fact that it is a City event also does not matter, that is not exempt from Federal copyright laws.

Where this should matter to the school is that they are likely to be liable for what is shown. From the Movie Licensing USA site referenced:

> *What if an outside organization such as an After School Program or Summer Camp wants to show an entertainment movie in our facility?*
> This is only legally permitted if the school itself has a Public Performance Site License from Movie Licensing USA. Schools without such a license will be held liable if an outside organization involves them in copyright infringement by permitting movies to be used in their facility.


It is typically the venue that is required to have the appropriate licenses and that is liable for any action or penalties, something the school may want to consider addressing when they let outside groups use their facilities.


On the projector, you have several time mentioned using a smaller image. If you are using a typical portable projector then you will likely have some zoom capability but you can't just put the projector anywhere you want and get any size image you want, the lens will be limited in the image size possible based on the distance the projector is from the screen. Also consider that if the projector was intended for typical classroom use then that is likely the size screen and viewing area it will support. If the Auditorium is darker then you may be able to have a larger usable image than in a classroom, but unless the projector is overkill for the classroom applications or you have very large classrooms, then it may be limited in the image size and projector location possible.

The ambient light levels my require some balance. Not being clear on the application, it sounds like you may have a situation with people coming and going during the event, if so that may require having more ambient light in the space for people to safely enter and exit than you might in a normal cinema application.


----------



## MillburyAuditorium (Sep 28, 2009)

Thanks everyone~

Well, The Millbury Music Parents Association, who is putting on this movie(s) have always done everything they do lawfully, getting a raffle license when they put on raffles, etc etc, so I am sure they will do right with this as well. I will inform them of it and if any copyright where to be ensued then charges would be against them. But first I would ask nicely if they have the license 
But either way it really isn't up to me what the school lets people do in the theatre, although I have some say, the school wont pass up the money offered to rent the facility 
I just need to do what I am told 

Museav,
The projectors aren't made for the classroom, classrooms are supplied with Over-Head projectors, so the couple media cart projectors we have, one of which I will be using, are intended for the auditorium or even the gym. We project videos etc. on the walls of the gym if a school wide "concert" is to be held.

I will have to ask the association putting it on if they are closing doors when the movie starts, etc.


----------



## museav (Sep 28, 2009)

MillburyAuditorium said:


> Thanks everyone~
> 
> Well, The Millbury Music Parents Association, who is putting on this movie(s) have always done everything they do lawfully, getting a raffle license when they put on raffles, etc etc, so I am sure they will do right with this as well. I will inform them of it and if any copyright where to be ensued then charges would be against them. But first I would ask nicely if they have the license
> But either way it really isn't up to me what the school lets people do in the theatre, although I have some say, the school wont pass up the money offered to rent the facility
> I just need to do what I am told


Personally, I would feel it was my role to inform the school of the situation rather than dealing directly with the User as it is the school that you represent and who will be liable unless they are otherwise covered by their agreements. Many schools that rent out facilities will have agreements or contracts for rentals that address issues such as licensing as well as liability for personal or property damage, supplied personnel and so forth. If you currently have no such existing agreements then this might be a good opportunity to pursue the school developing them.


----------



## SHARYNF (Sep 29, 2009)

Typologically the fee is about 100 dollars or 50 percent of the gate. (this is why most folks make sure to just as for DONATIONS. Some movies are restricted over 200 people etc.

It is the venue that ultimately has the responsibility. 

Fact is that it is only in rare instances that this gets enforced, usually instead of someone like SWANK going after the venue it is the original copyright holder.
From a legal standpoint the reason these are not widely litigated is that the law only allows a penalty of up to 5000 dollars so it is in a different ball game than illegal downloading with its huge penalties and high visiblity

Most organizations are not aware of the issues, and also that there is an organization that can handle the licensing etc. Just because a group makes sure they have gambling or alcohol licensing in place does not mean they are aware of the other issues. Since public exhibition penalties are civil based on suite, and not criminal and not locally enforced they do tend to get overlooked.

Certainly not trying to induce anyone to do the wrong thing, but at the same time I do think it is important to present a bit more information on the topic. 

Sharyn


----------

