However i want to confirm something, if you could help me out here.

My room length is only 13 FT, and i plan to get a full hd projector along 140" screen . Do you think this size will be suitable for this room, i just want the maxiumi size possible based on the 13FT length. Please advise

thanks in advance
R

Thank you for your response. That is what I thought I was doing "over thinking" this but I wanted to be sure.

At present I have no option but to put the projector at 19'11" throw, mounted away from a back wall, fortunately I have a 10.5 ft ceiling.

The height of the projector is mounted in such a way as the angle to the screen and the returning to the viewer's eye is nearly the same and after calibration and inputting the figures into your program gives me a calculated fl of 18-19. Which as the room has little to no ambient light is perfectly satisfactory.

The PJ is installed in that manner. And while it does not have the punch that mounting it at 14.5 feet does it appears to me, and I maybe just imagining (please tell me if I am) to really bring out the various shades of grey very well. A good comparison would be this looks more like an Ansell Adams photo, versus a good advertising photo where punch is more important than shades of grey, such as Mr. Adam's photos. The "Pirates of the Caribbean 2 " Blu-ray movie with mostly dark scenes looks great.

As we really only watch DVD and Blu-ray movies I actually like less punch and more detail but I think it is a matter of personal taste. Of course at this distance it is really not able to let one view TV in the daytime, unless it is cloudy, but we do not do that in this room.

Now the half-German genes in me (it must be exactly so) can sleep at night, fortunately the other half of the genes are mostly Russian and as usual they do not care a less.

So once again,

Thank you

One more question, in the Epson 6100 manual is written "Ideally, keep the projector and place so its lens is centered between the top and bottom of the screen.

In the manual, however, the maximum lens offset A (upper half of screen) if PJ is table/bookshelf mounted is, at 11.8 to 25.2 feet distance, 27", maximum offset for B (lower half of screen) is 86". Does this mean that the strongest fL is centered 69% up on the screen, equation as follows (((1-(27/86))*100), or is this number irrelevant.

If true would it affect the measured height at which one would calculate the light bounce in a higher gain screen say 1.24 and up? Would the measure angle be taken from 69% up on the screen and not halfway up?

If it does affect where the measure is taken from would it be best to do as Epson suggests (center on the screen), or shelf mount it higher than center and offset down, or ceiling mount upside down? The only issue I see if this percentage offset does affect the maximum fL the ceiling mount upside down angle would create a smaller luminosity angle to the viewer requiring a very long drop from the ceiling, if PJ is placed at around 21 feet, the drop would be 44", a longer drop if closer, assuming persons eye level at 37".

So what I am questioning is the luminosity center on the screen different than actual center if looking at the screen, and where on the screen is it best to take the angle measurements? Roll off percentage starts to take its toll at 21 feet.

I realize that I could be over thinking this but as you can see it would change the numbers as to where the angle is calculated from, but it is bugging me not knowing.

In my own case the 16.9, 1.24 gain Wilsonart Designer White homemade screen is a 110" diagonal, the throw distance for the present will have to be 21', hope to change to 14.5 feet (under negotiation), and the screen sits 44" off the floor. I know 3-4" too high. We sit 15’6” from the screen. The arrangement cannot easily be changed because of being married to, as Rumpold of the Bailey said “She who must be obeyed”.
Thank you for a very quick reply to my last question, after this I promise no more unless I do not understand the reply.

Having been using your program and it is great.

Question, does a program exist that gives one the optimum drop placement from the ceiling so as to achieve the highest fL at the viewer's eye. Assuming that the distance of the viewer from the screen and the PJ are different.

Please correct me if I am wrong (most proably am geometry was never my strong point) but ideally should the viewer's angle and the PJ angle be the same?

Thank you for all your hard work on this program.

Having a room 13 wide by 15 feet depth – how do I calculate the maximum height of my tv over the fireplace? Thanks LP.