Originally Posted by bpassman
Help! I'd like some feedback to make sure I understand the ProjectorCentral Throw calculator before I buy a new screen and PJ. Today I have an Epson 8350 and Carada 110" 16:9, but want to move up to a AT CIH screen setup.
My room is 16x24 light controlled and I have decided to go with a PJ with lens memory. I've narrowed it down to either the Panasonic PT-AE8000 or the JVC DLA-X500R and looking at a Silver Ticket 138" Curved AT screen.
I've attached 2 screenshots of the PJC throw calculator for each PJ for my questions. Each PJ calculation was set to "Diagonal Range", 2.25:1 Aspect Ratio, 1.0 Screen Gain and a 16' "Throw Distance".
1. For each PJ, does the light blue shaded area under the category "Image Diagonal" represent the entire throw range based on the Zoom and distance from the screen?
The easiest way to use it is:
1) Pick "Throw Range" in the zoom box. This will let you pick a screen size and adjust throw to match it.
2) Figure out the width
of your screen. Since you're zooming this is the part that matters, it's "fixed"
From that you can figure out the range of throws that will fill that 2.35:1 screen size. The next step is to make sure that you don't have it too far away that you can't zoom down to 16:9. One way to do that is to do the same as above, but set your screen to the height
of your screen, since this is what must match for the 16:9 image.
After that, any throw that works for both setups, will allow you to zoom
2. Since the throw calculator locks "Throw Distance" and "Image Diagonal" sliders together, as long as you moved the "Image Diagonal within the range of the light blue shaded area, the image brightness should get slightly brighter?
Just ignore anything related to brightness from that calculator, I'm not sure what they use, but I've never seen a consistent correlation between their numbers and anything else.
3. I think I'm missing something, any idea why the AE8000 with 4000 lumens performs worse than the JVC with 1300 lumens in the same basic configuration?
I don't know about PJC's calculator, but firstly, the AE8000 is "only" rated for 2400 lumens, secondly, that rating is a bald-faced lie, ok, that's overstating it a bit, but that's only possible in terribly uncalibrated configurations. Once you calibrate the AE8000 for D65 and Rec709, it's down to 800 Lumens or less:
The JVCs can actually hit reasonably close (over 1000 Lumens) once calibrated: