CurtPalme.com Home Theater Forum

daves123 · Joined: 16 Jan 2009 Posts: 126

I'm trying to setup my projector on a 16 x 9 screen. I was using a 4 x 3 screen. Now, is throw distance calculated from the
4 x 3 equivillint screen size? So, if I have a 106" 16 x 9 screen, and my lens throw is 1.3x would my throw then be 138"? Or, am I wrong.

**kal** · Posted: Thu Jun 18, 2009 1:19 am Post subject:

Don't use calculations. They're only estimates at best. Look into the tubes and do it the right way.
To do that use the instructions on this page: http://www.curtpalme.com/TubeCondition_PoorInstall.shtm

Using calculations are like giving driving directions that say "press the gas pedal 1/2 way down for 10 seconds, then turn the steering wheel left 90 degrees for 2 seconds" instead of actually looking out the window at where you are. It doesn't make any sense to use calculations. They're only pessimistic estimates at best.

Kal

daves123 · Joined: 16 Jan 2009 Posts: 126

Yeah, I know it only gives a rough idea. The reason i'm asking is because I ceiling mounted an ecp in my bedroom, and it wasn't filling my new screen horizontally, even though it was far enough back according to the throw distance. I also still had a fair bit of raster that could be used, and the horizontal width was maxed out. I found the width master pot on the green board, and now all is well. I thought maybe it was because a 106" widescreen, is equivellint to a much larger 4 x 3 screen.

**kal** · Posted: Thu Jun 18, 2009 1:39 pm Post subject:

Good stuff! Glad you got it all figured out....

Kal

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

I just set up for the desired width of picture and the height is whatever it is for a given aspect ratio. Throw distance won't change with an aspect ratio change if you stay with the same picture width.

CJ

stefuel · Posted: Fri Jun 19, 2009 12:14 pm Post subject:

I'm as guilty as most here when it comes to positioning a projector. Yes I will drag as much phophor out of the face of the tube as I can but there is good and bad things to consider. On the good side, the more phosphor you use the higher your resolution can be. The image will be brighter and the tubes should last longer. On the down side of things, if it's done incorrectly and you are to close to the edge, you can overheat and crack a tube. You are using the electronics more then they were designed to do. If the image is to big for a particular lens to handle, edge focus can suffer. I defend manufacturers specifications, especially for projectors like NEC. They can be a bitch even for the experianced ones to set up. If you follow the manufacturers mounting instructions to the T, you will get a perfect image but at the expense of a little less resolution and tube life.