Vertical Offset Help

[Mr. Met]

HI All, I am starting the process of setting up my sim and I am really struggling with the projector. The vertical offset is really throwing me.

Here is my planned setup:

-Ceiling height = 9' 10"
-Screen size = 12' w x 9' h
-Hitting zone to screen = 10'

I am looking at the Optoma GT1080 Darbee and projector central shows it needs to be placed 8' from screen, but that it has a 17" vertical offset at this distance. How does this factor in to my ability to fill my 12 x 9 screen?

With my above dimensions is there a better projector option to fill my screen?

Thanks for the help.

[wbond]

I have the same projector, what it means is that the top of your image will start 17" below the center of the lens. So if you mount it close to the ceiling, your image will start around 20" or so below the ceiling which will leave you with less than a 9'H image. Also, this projector has no zoom so placement is critical. There is a BENQ short throw projector that lots of people use that has way less image offset and has a zoom. Might want to check that. I can't remember the model, but if you search you should find it easily.

[Mr. Met]

Just so I understand this, do I need to drop my projector down the same distance between my ceiling height and the top of my screen? In this case 10" (9' 10" ceiling minus 9' screen). So that would be 2" projector offset plus 8" additional?

Or do I try and keep my projector as close to the ceiling as possible and make up for those 8" by tilting the projector down so the image is brought lower and then adjust the picture somehow using keystone?

[wbond]

Not sure if I understand your question or not. Vertical offset is where the image will start in relation to the center of the lens. For the optoma, it has one of the largest vertical offsets that I have seen. So to fit your screen width of 12', the lens needs to be 9'(108") plus the vertical offset of 17" off the ground, for a total of 125". The problem is you don't have 125" of height to your ceiling. So now your image size will be reduced to your limitations. I would say that you should be able to get the lens to mount about 6" below the ceiling. That will give you an image size of 129"W x 97"H and the projector will be 7'2" from the screen. The vertical offset for this image is 15".

You should not tilt the projector, no reason to.

[ughly32]

I am getting a Optoma GT1080 Darbee delivered tonight.
The attached image is numbers I ran using their calculator.
https://www.projectorcentral.com/Optoma-GT1080Darbee-projection-calculator-pro.htm

Best Regards,

[Supraracer]

The top of your screen needs to be 17" below the center of the projector lens. It can be more or less a little but then you will need to use keystone adjustments and will affect picture quality on the edges.

[Mr. Met]

Do I need to worry about the distance between where my mount connects to the projector and the center of the lens if I am trying to get an exact measurement of where the top of the picture will be?

In other words, is this how I need to look at it:

Height of project mount (5")
+Top/bottom of projector to center of lens (2"???)
+Vertical offset of the projector (17")
= Distance from ceiling to top of picture (24")

If so, how do I determine the distance from the end of the mount to the center of the lens? Or is this inch or two not enough to worry about?

[Supraracer]

If your projector is not already mounted, you could put the ceiling mount on the projector and turn it upside down on the ground. Get the measurement from ground to center of the lens. Then use that plue 17" for your offset. You would be close enough to not worry about it. Mounting a fixed lens projector by yourself is very tedious.