Originally Posted by AnnapolisSony
Soooooo, now I am kicking around the possibility of a back wall mount for the PJ. Lally column to back wall measures 21'3" so back wall to false wall/screen would likely be in the 20'9" to 20'11" range. If this is a feasible option, I will likely order the PJ and runs some tests to see exactly what I am working with before I go any further with the build. I can always return it if it doesn't work.
There are several PJs out there that I'd consider but for the sake of this discussion let's use the EPSON 5050UB. It shows a range of 10'4" to 20'6" for a 100" screen (16:9 format). The depth of the 5050 itself is 17.7" so mounted off back wall would put my lens inside that 20'6" range as the lens would likely be somewhere around 19'3" - 19'5" from the screen. NOTE: I have not committed to a 5050 yet...but just using it for the sake of discussion.
It's either try to build a housing off of the framing on the beam (in front or below) or go with a back wall mount. Leaning towards back wall at this juncture because building any sort of housing for the PJ in front of or below the beam is right above my first row of seating so I'd have a noise issue and it would be super low. I still have to work through whether or not it will be feasible to go back wall with a 42" counter height on a snack ledge (and stools) but, again, I could test that with an actual PJ in hand.
I have to concur with Tedd. Allow me to give you some pointers to consider regarding PJ mounting, throw distance, and seating.
This is going to sound cliche', but you don't want it too close, and you don't want it too far away. You have several factors to take into consideration in terms of PJ projection no matter where it is mounted. The ideal location would be in front of your front row of seats, sitting on a table. Obviously, no one wants that. We all compromise one way or another.
Rear Mounted PJ
Rear mounted projector setups can
work well, but they typically work best when the room is on the tall side.Think about how the PJ operates. It will be projecting a cone shaped stream of photons downrange. Mounted further away from the screen, you have the opposite problem from a forward mounted PJ. From the rear, you have to worry about that cone being too wide, such that it gets partially blocked too easily by people or objects. Furthermore, you need a more powerful light cannon (as Tedd pointed out).
So, unless you have a really big screen, and/or lots of headroom, that PJ needs to be able to focus high amounts of light into a narrow beam that does not widen appreciably until it gets over the heads of seated movie watchers.
You're going to need to pay special attention to several factors; notably (and this is just a starting point):
- PJ light output (you will need a lot)
- Long throw distance capability
- Mounting height (ensure the beam is fully over everyone's head when seated, and ideally when standing up)
- Pay close attention to the angle of the light cone, and it's width at any given point in the room
Now, what if you mount the PJ up close? Then it's opposite land.
Forward Mounted PJ
Forward mounted PJs usually end up just above the heads of the 1st row folks, or thereabouts. Some of the challenges include:
- Short throw / Close to screen (can I get it wide enough if the screen is big?)
- Vertical adjustment range of the PJ is critical
- Ceiling height is needed to clear heads of people standing up and/or avoiding visual blemish for rear seat viewing (PJ in field of vision)
- Noise (potentially)
Now, let's talk about the viewers.
You're not planning to use a riser, so that helps. Either way, you still need to work out seating distance, eye height, and screen height. All those angles are going to play into what happens when the cone of light from your PJ is heading downrange. This is especially true if the PJ is behind the rear row of seats.
Summing it All Up
Bottom line is I agree with Tedd. I would look at mounting the PJ above your bar seating area. That's likely to be one of your best spots from a lens-to-screen distance perspective. I understand you may be hesitant about that due to the need to pass the light cone beneath the bulkhead above roughly where the 1st row of seats will be. And of course, you don't want anyone in the bar seating area to be distracted by the PJ or bump into it.
Taking another look at the area forward of the bulkhead.... If you want to target that area, your first challenge is you'll need a very short throw PJ. Next, the vertical offset of the PJ needs to be capable of hitting center screen. Where and how will you mount a PJ here? On the ceiling, forward of the bulkhead? That would make a nice place to hide wires, but then you will be running into challenges with vertical offset of the PJ versus screen mounting height. Will you be causing your viewers to walk away with a stiff neck? This is something equally important (perhaps more so) to take into consideration: screen mounting height.
Don't even consider shopping for a PJ until you are further along with your room. Details can and will change. You need to know exactly where people will sit and what height the screen will be mounted at, and what its dimensions are. Once all that is set in stone (as much as it can be), then start getting serious about the PJ.
You also have bigger fish-to-fry right now, IMHO. I suggest focusing on what you can do about widening the room to its full potential. What would it take to get one or two beam support columns relocated?
p.s. You could consider a rear projection system, since you may have enough room available behind the screen. They are exceedingly rare, but the concept does exist. Their biggest advantage is no PJ in the room. Problem solved! LoL.