# projector education needed.



## mixmaster (May 28, 2009)

I'm a sound guy. My boss is a lighting gal. Neither one of us are video or projection people. Until now, when we have an event requiring projection, we combine our efforts and have usually managed to come up with reasonable solutions using equipment available from our university's IT department. As projection technology has progressed, we find ourselves in need of projection beyond what we can do with classroom sized projectors and finally arranged to purchase something more useful to us. I'm hoping that people here can give me some ides as far as things to look for when buying projectors and lenses, and maybe some resources that I can look at to get a crash course in projection, so I know what I'm looking at when I see spec sheets. So far we have had a couple people come in who have snowed us with a bunch of techno-babble that I only half understand and then of course they "just happen" to sell a projector that does exactly what they say we need. I guess I'm looking ideas or information from something a little more independent. I've done some searches and some research but still don't feel like I know enough to make an informed $10000 decision. Any ideas or things to consider would be appreciated.
Ultimately, I have 2 venues that this needs to be designed for. Primary venue is an 800 seat proscenium theater. We would like to be able hang the projector from a DS pipe and shoot to the white back stage wall or shoot from an US pipe and rear project onto a screen hung all the way DS. That's 20 ish feet either way. We would also like to be able to shoot from the balcony rail to the stage, either the screen DS or the wall US. that would be a distance of 100 feet or so, Depending on where the screen gets hung or if we go clear to the back wall. I understand this would require different lenses and a very bright projector. Since this is for both theater applications and PowerPoint delivery during lectures, it need to be capable of cutting through stage and house lighting.
This projector will also get used during our graduation. Currently we hang the screen above the stage in our gym and rear project an image from the cameras so everyone can see students walk across the stage. Currently we use 2 2500 lumen Sonys with the images overlapped to make the picture brighter. It's almost bright enough. They put new brighter lights in the gym this year and everyone noticed the screen seemed darker and that's part of what's driving this whole thing. Given our 2 2500 (5 thousand lumens total? Does it work like that??) doesn't quite cut it anymore I'd guess we need to be in the 8000 lumen range maybe?
I'm still learning this video stuff so if anyone has suggestions, recommendations, or things I should consider, please help.
Many thanks
Matt


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## museav (May 28, 2009)

Yes, the two 2,500 lumen projectors, if they were perfectly aligned, would be equivalent to a 5,000 lumen projector. The problem with using your existing projectors for comparison may be that they and whatever projector you look at may be specified at X lumens but that is likely with a new lamp and the best possible lens at its optimal operating point. What you may be actually getting from the existing projectors may be less than 2,500 lumens and you may not get the full rating from a new projector for that long nor with a short throw lens like you may require. But it's probably a good place to start.

Other than brightness some common specs to consider are throw distance (the distance from the screen to lens for a given image size), contrast (realistically not an issue anymore), native resolution and format (4:3, 16:9, 15:9, 5:4, etc.), physical inputs, noise levels, single or multiple lamp (the latter can provide longer usable life and redundancy or high brightness when you need it), lamp life and replacement lamp cost and warranty. Some newer projectors also offer filter cartridges that automatically move new filter matrial in to place rather than having to clean the filter, this may not be a big advantage for desktop projectors or portable projectors but can be a very nice feature for projectors installed in difficult to access areas.

Don't overlook the role the screen may have in image brightness, image contrast and viewing angles. Many materials may work as projection screens but may vary greatly in how well they work.

Having different lenses can be helpful and many projectors in the range you seem to be noting offer lens options. But lenses can be expensive and some, especially very long throw lenses, incur significant optical losses, in fact some lenses can reduce the brightness actually achieved by 25% or more from the published projector performance. Some projectors are also very difficult to change lenses while a few are designed to make it easy. This sometimes takes a little more digging to discover such as going beyond the specs to read the manuals.

The one critical component missing in your description is the image size. Brightness, lens selection, throw distance and other factors are all going to be directly dependent on the image size. So a good place to start is usually the desired image size (or enough information on the audience area, applications, etc. to determine that) and the desired native resolution and/or format.

Da-Lite screens has a lot of good basic image information on their web site including their Angles of View series. Projector Central is a good resource to narrow down projector product choices based on specific criteria or specs.


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## ruinexplorer (May 28, 2009)

I have relatively little to add to Brad's well informed post.

On the issue with contrast, I agree that in the applications you listed, contast will not be a selling point in your projector choice. The only reason to consider contrast is if you plan on doing any cinema presentations. 

Other things to consider (that a salesman will bring to your attention) is the type of inputs that you will need: VGA, DVI, composite, component, RGBHV, HDMI. Since you plan on moving the projector to many different places, you may need to consider how you plan on controlling it. Will the IR remote be enough or will you need the abiblity to extend the remote or use IP control? 

Last, do you want LCD, LCOS, or DLP? Here's a very basic rundown of those technologies. LCD filters the light that passes through it and will tend to lose the ability to filter the light over time. This will make your color rendition poor as colors bleed through where they are not wanted. Conversely, DLP has mirrors which reflect the light, but run at a higher cost than LCDs. Your colors will last longer this way. When cost is a factor, they will try to sell you on a single-chip DLP. These are priced competitively with LCD projectors. They use a color wheel that spins rapidly and the mirrors are timed to allow the light to pass through with the appropriate color. In my experience, these projectors have a lower apparent output to their three-chip counterparts or comparable LCD projectors. The last type is Liquid Crystal On Silicon, which is kind of a hybrid of LCD and DLP projectors. Instead of filtering the light like a standard LCD, these reflect the light similar to a DLP. They will still suffer color loss, but will run many more hours before this is noticeable. Also, with DLP, the light engine is normally sealed on new projectors, which keeps your optics free from dust.

As for your question of training, you have found a great resource right here. If you are looking for reading up on the subject, Amazon has a wide variety books on video presentation (after you weed out the broadcast and video production books). If you are looking for workshops, Infocomm offers some great online videos as well as in person training. Also, you can check out the Master Classes offered by Live Design a couple times per year.


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## mixmaster (May 29, 2009)

museav said:


> The one critical component missing in your description is the image size. Brightness, lens selection, throw distance and other factors are all going to be directly dependent on the image size. So a good place to start is usually the desired image size (or enough information on the audience area, applications, etc. to determine that) and the desired native resolution and/or format.



And in that lies on of my bigger concerns. We have an existing (read that as very old)9x12 fold up screen that we hang or stand up anywhere we do rear projection or need a large portable screen like for our graduation. We also have some of those small rollup screens that hang on a tripod for small lectures and stuff. From there we jump up to the back wall of the theater. We have had clients who want to shoot an image up the for a backdrop to a performance, and we use it as an US screen at times for lectures and corporate presentations. It's not uncommon for us to need an image 15 feet wide, and we could easily need an image up to 20 to 30 feet wide. I'm concerned that we will have trouble finding a single projector, even with multiple lenses, that will give us the flexibility we need.
Thanks for the help ideas and the reading material. I'll get right to that.
Matt


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