Originally Posted by NLZ
Incredibly noob question coming up...
Says that mounted I need the projector to be about 9 inches above the top of the screen I'll be using. Why? Still need to buy a mount/screen, leaning towards Fixed Elite and 4 inch from ceiling mount, however I'm wondering why I can't just project the image to the top of my ceiling (where I want the screen to go, covering basically entire wall area before the ceiling drop). I held the projector up as high as I could myself and the image appeared to project up there, but perhaps the image was a bit distorted and I didn't realize? What's the advantages to projecting 9 inches below and the disadvantaged to projecting same height level or in this case about 3-4 inches above the lens?
Yes, the HD20 is a fixed offset projector. So it will always cast the image edge a fixed % from the lens center. So with no keystone adustments, mounting the project flush to the ceiling will have an offset.
So if you angled the projector to move the image up, you will have to use the digital keystoning. If you are going to use a computer/laptop with the projector, I highly recommend not using any keystoning. But that would also mean for a squared up image; if will be down away from the ceiling.
Also, if you have a light colored ceiling, having the image close to it will cast light back on the image and cause the top to appear a little washed out depending on the scene of the movie or content.
Anyway, those are your only 2 options.
1. Tilt projector and use digital keystone. This causes the image to not be 1:1 from a 1080p source. It does a great job, but the affect is noticeable with a computer where the straight lines will not match the projectors pixel structure due to digital keystone.
2. No keystone. But then no PJ tilt. Then the only way to adjust image position is to shift the whole PJ up and down, left right, back forth. Keeping it square with the screen and parallel with the ceiling/floor.
I am currently using a 125" DIY screen with option 2.