Originally Posted by mitchdzj
Thank you for the reply. I have a few noob questions.
Why is it bad to have the zoom set all the way to the top of the zoom range? I do have it set like that and it just fits within the width between the two windows with a few inches to spare on each side. The PJ is actually mounted on the back wall on an arm. I currently don't have the arm all the way out so I have some room for adjustment forward. My screen just needs to fit within the space between the windows so the throw i stated and the 92" screen size is more of a ballpark. I'm now more concerned about the zoom set at the top as you mentioned. How much leeway do I have with that setting?
If I go with a whiteboard can I paint silver fire over the n8 paint at a later date? Would there be a difference in quality vs sintra?
While some PJs produce maximum Lumen output at Full Zoom...others actually lose a small percentage. Still others can introduce a slight distortion at the edges called "Barreling" ...and while the edges of the projected beam might actually be straight, the image wiithin can show a slight degree of 'flaring" along the extreme side edges and each corner. Such would be most noticeable when a straight line goes into / out of the edge of the screen. PJ optics have greatly improved, so for most, if not all situations, optically abhorrent image distortion is less likely.
Unless the image, through poorly done or necessary PJ placement requires the use of Keystone correction. Then things can and often do deteriorate to a point is does become visually obvious.
So, all that says is that Lumen output concerns at Full zoom are not the real abiding issue as much as placement concerns are.
situation, he has a DLP unit that has no Len shift. So he must do three things exactly right to get a squared image that also fits precisely in his desired screen sized Framing.
1. Place the PJ precisely perpendicular to the wall, with the Lens centered exactly within the sides of the Screen's width dimension.
2. He has also be certain the Lens is precisely at the right height "above" the top edge of the screen, and also is completely level.
3. The complete lack of any further ability to adjust Zoom means that whatever size his positioning at Full Zoom" allows is the biggest it will ever be. Reducing the Throw even a very few inches allows for at least a bare minimum amount of adjustment.
That was indeed what I planned on doing when watching 2.35 in my CIH format. I hadn't seen anything indicating that is was a bad thing...
As long as you see none of the issues listed above crop up, your probably "all good", and getting optimal lumen output delivered to the bigger (wider) 2.35:1 formatted image. Under all circumstances where a 16:9 image is chaged out for a 2.35:1 image, and is done without using a true Anamorphic Lens and "Stretching Correction", a loss of up to 30% of Lumen output is the result because that amount of percentage of the available light a 16:9 PJ puts out is wasted as "Masked". Under those circumstances, absolutely you want to place the PJ just as close as possible to it's minimum Throw. But even so, allowing for a few extra inches of Zoom adjustment is always a wise proposition, especially if one cannot place the PJ first, shoot an image, and then mark off the [perimeter of the screen's outside edges. Even doing that, it is wise to still then frame the painted area just a inch or so smaller in from the original marked-off image size.