Help Interpreting Projector Specs Before I Buy

[Senorwanderer]

I have been struggling to find a projector that is in current production that fits my needs, but I think I've found it! I posted about it here. The discussion in this thread has moved towards how to interpret the vertical offset, and I need help determining how high I can mount my projector above the image.

below images are the throw distance calculation and the specs from the product manual. The projector is a Panasonic PT-VZ580U



The Throw Calculator says that the ceiling mount can be +45" from the edge of the screen, and additional 35" using the lens shift. The info in the projector manual for 150" projection image size (highlighted) shows 0.37' - 3.31' as the height from edge of screen to center of lens.

I'm looking for confirmation that this projector can be mounted ABOVE the top edge of the screen. The image height will be at 96", and the projector will need to be mounted at approximately 120". This info seems to confirm that's possible.

Thanks for the help!!!

[stubious]

Based on my own research on this topic for an Optoma (https://www.projectorcentral.com/Opt...ulator-pro.htm) - yours seems to need to be mounted overlapping the image (if you look at that Optoma one, it has a negative number and sits 'outside' of the image frame). Image below for mine as well.

From the Panasonic you are looking at, at the dimensions you entered, it would sit 45" above the bottom of the image (if floor mounted), or 45" below top of image if ceiling mounted.

Now, as you mention, it has a vertical shift - 40% from what I can tell. So, you should be able to shift it by 40% of the image height (e.g., 40% * 90" = 36") - which, would still leave you with a 9" overlap - e.g., the middle of the projector lens would sit 9" below the top of the image. If you needed to go further, then you would mount the projector higher, but tilt it down, lowering the image, but turning it into a trapezoid as it isn't perpendicular to the screen - and then needing to use keystone correction to get it back square. But that would be at a loss of quality as it is done digitally - ideally avoided for major corrections.

So ultimately - if you are wanting a unit that sits above the image n, the math suggests to me (and others, please chime in if I have the wrong end of the stick!) that you want to look for a unit with a negative vertical offset instead....

[stubious]

These two seem to fit the bill depending on the brightness and budget ($1700-$3k) and are both no screen overlap (0 offset) - so you'd need need a pole to drop the projected to the appropriate height, but very doable.

• https://www.projectorcentral.com/Ben...ulator-pro.htm
• https://www.projectorcentral.com/BenQ-LU710.htm

[Senorwanderer]

Thanks for the replies! So I really do have it backward. I need a projector with a negative vertical offset number if I want the projector mounted outside the image. I've managed to workout the confusion so I'll explain here for the sake of posterity. I think it comes down to lazy coding on the calculator website. If your projector is "mounted" right side up, "below" the image then you get a negative offset. if you tick the box for a ceiling mount that number stays negative although the illustration flips to the top of the screen. It's hard to conceptualize a negative number being above the screen, but that's what we've got! Long story short, if the vertical offset is a positive number then the projector is mounted inside the image, that distance from the edge. If the offset is a negative number you can mount the projector outside the image.

In case you're curious, the projector that makes all my dreams come true is the Optoma GT1080HDRx


carry on. . . .