Not logged in
 
Author
Topic: Need help buying projector
member
Joined: Apr 18, 2017
Posts: 2
Reply to PostAlert Moderator
Hi guys,
This is my first post. I am a LED wall guy and can answer questions about that all day but I try to stay away from projectors as they intimidate me a bit haha.

Got a client wanting to spend some money on their office, trying to get it "pop".
They have 2 walls in 2 different parts of the office building.
The rough specs of said walls will be 40 feet wide by 12 feet tall.

I use Resolume for all my LED walls and that software has some Great projection mapping and edge blending tools.

I am planning on getting 2-3 projectors per wall and using a Datapath FX4 to have all the projectors sync'd up as one continues image.

The walls are a dark brick and the client wants to throw images up on the wall to projection map it, in order to bring that wall to life.
I make a ton of content so I can make this happen, but what I have absolutely no idea on is:

How bright should the projectors be? (looking at a 10K Laser projector)

What lens should I use? (looking at a 0.8-1.0:1 lens??)

and at what distance should I put the projectors?
Would 2 work at 20' per projector or would that be stretching the intensity down too much?

This will be in an office building with overhead lights and windows. The projectors will be mounted from the ceiling (about 16-18 feet tall exposed ceiling)

Since there's no screen, how many projectors and how bright should they be?

I would like to keep the cost of the projectors below $20k each. Preferably below $15k as if we have to do 2-3 projectors per wall (4-6 total) that can add up.

And yes I know..... possibly $120k+ just for office bling!!??!! yeah... Wish I had that kind of dough #smh


Thanks for any help you can send my way. Sorry for being a noob at this. More than happy to share Novastar and Resolume with anyone needing it
moderator
Joined: Mar 28, 2005
Posts: 12,390
Reply to PostAlert Moderator
The big issue is going to be the reflective characteristics of the wall and reading light output before hitting the wall and what is coming off of it. Assuming a .6 gain on the wall (nearly half the light is lost), then that increases the necessary light output by about 80% on the projectors to achieve the same impact as a neutral gain screen would.

Typical specification is 80 advertised lumens per square foot of screen space to achieve a 12:1 contrast ratio in a boardroom under typical florescent lighting. I would expect a need for no less than 150 lumens per square foot of screen space.

Projection DISTANCE does not impact lumens other than what the lenses may do, which often isn't much. As well, longer throw is better, especially with edge blending, as shorter throw lenses introduce barrelling and pincusioning issues. So, use the longest throw distance possible. It will increase reliability and lower maintenance costs.

There will be maintenance costs due to color shift and alignment drift. Unlike a video wall, projectors just aren't locked in place next to each other and a millimeter of drift equates to inches of misalignment on screen.

The math on brightness is easy after you know the square footage and the requirements: 12x40x150=132,000 lumens.

A typical BLACK movie theater uses screens about 40 feet wide and typically uses $100,000 projectors in those spaces. I think that you are really underestimating things when you think 10,000 lumens will cover it nicely in a group of 3. I think you may be struggling to deliver with a group of 3 30,000 lumen projectors.

I struggle to feel like this will work as desired within an appropriate budget. I would more likely look at low cost LED wall solutions, which are still pricey, but will have far greater impact. Maybe a LED curtain design.

Projectors, when done properly, aren't really a cost saving item in these situations. If you would expect it to be a $500,000 or $1,000,000 LED wall installation, then it likely needs to be similar for a projection setup.
AV Integrated - Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.
member
Joined: Apr 18, 2017
Posts: 2
Reply to PostAlert Moderator
Thank you AV_Integrated!

This was VERY useful!
The surface they will be projecting on would be literally an indoor brick wall (dark red-ish brick and grey grout).

I wouldn't think they would need a crazy bright image, but defiantly something comparable to shining a Leeko light with a gobo, but obviously, animated as is the purpose of the projectors.

So with any 30,000 lumen projector costing over $100k a piece, I can get a 1.2-2.3 mm LED wall to cover this entire area for a little under $20k. I think this might be a better option for the $$.

Thank you again for all the information. You're a beast of information.

Hope you guys have a great week!
moderator
Joined: Mar 28, 2005
Posts: 12,390
Reply to PostAlert Moderator
We have always used video walls if resolution was important, like these:

http://www.necdisplay.com/p/large-screen-displays/x464uns

They are around $4,000 per unit, which is pricey for an area that large, but produce a very fine, bright, and vibrant image. Kind of like creating an LED video wall, but it won't have the pixel gap and will be extremely high resolution.

But, we have done a few LED walls as well. LED seems to have issues with stuck pixels, but I'm not sure if that's been improved upon in recent years or not.

Projectors still very much have a place and a purpose. A $15,000 laser/phosphor projector can fill a 150" screen in a boardroom quite nicely with a retractable screen leaving a clean look when all is said and done. But, on my side of the commercial market, pretty much everyone has gone to LCD flat panels from 50" to 90" diagonal. Some 98" models from time to time as well.

We just did a 33' LED wall though. I think 1.2mm.

I would be interested in knowing what product you are using for LED work that would allow you to fill 40' of width for under $50,000.
AV Integrated - Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.