Well, I suppose that would be Avoid at MOST cost...

In the Samsung thread http://www.avsforum.com/avs-vb/showthread.php?t=877066&page=9&pp=30
I brought up my keystone situation. Some replied that one should go to pains to avoid. At least one has replied Don't worry about it. (I am at -4, I suppose that means percent?)

Then on this thread, some chime in saying it is no big deal if sparingly used.
http://www.avsforum.com/avs-vb/showthread.php?t=886284

I am sure this issue comes up for a fair number of us. I'd like to ask how many accept KS in their setup, and how many have taken unusual pains to avoid it. How many can actually SEE its ill effects at a correction level of 5% or less?

In my situation, I could of course just move my screen up 4-5", but it is already a bit on the high side (eye level is at about 1/4 screen height). Am considering tilting the screen but concerned about it looking strange. Only other recourse seems to be padding the area between mount and ceiling with wood or metal, again not an attractive proposition.

BTW, I am not out to impress anyone but myself and my immediate family. We will rarely have visitors and I give a rodent's posterior what they think anyway. But we like to enter our little haven at the end of a busy day and really enjoy it, and environment, although taking a back seat to actual PQ and SQ, is also important to overall enjoyment.

I'm using it at the moment as the way the screen is temporarily mounted it is not quite parallel to the lens face. It doesn't appear to make any difference that I can notice (though I'm not a videophile, by any stretch of the term). My use of it is quite slight, though. I imagine something that requires a major keystone adjustment would have some sort of visual artefact.

I can see the shape change when I engage it, but it has not distorted any films or TV shows I've watched, so, frankly, I don't worry about it.

Tilting a screen is FAR more distracting to me than a trapezoidal picture or the fact that I'm (hypothetically, in this case, or lack of it) using keystoning.

Tilting a screen is FAR more distracting to me than a trapezoidal picture or the fact that I'm (hypothetically, in this case, or lack of it) using keystoning.
I'm not sure I understand--are you saying you'd rather NOT use keystoning (even a tiny amount) to correct for a slight tilt that may not be easily avoided? Obviously, no one wants to watch a screen tilted at a large angle, but I think most people who employ keystoning are doing so for slight variations. Are you saying it is unacceptable under any circumstance and that removing the tilt is the ONLY acceptable option?

I don't need to use it. Barely, that is. I use Window's desktop programs for some video editing. I can see it with desktop work but I cannot see it when I watch a film. So I don't use it at all. But if I only watched films I wouldn't mind a couple of keystoning notches.

I don't know if the effects of keystoning will be more obvious when we are all using HD (Blu) DVDs and 1080 PJs.

Best to avoid it but if have to use it then use it.
How bad it is depends on the scaler on board of the projector.
Try it and find out. One thing that certainly it will do is that you cannot do 1:1 mapping any more.
Tilt the pj and see how trapezoid the image becomes if not to much hide the sides by overscanning it a bit if you have nice and wide masking on the sides of the screens. I have done that without using KS in tha past.

I'm not sure I understand--are you saying you'd rather NOT use keystoning (even a tiny amount) to correct for a slight tilt that may not be easily avoided? Obviously, no one wants to watch a screen tilted at a large angle, but I think most people who employ keystoning are doing so for slight variations. Are you saying it is unacceptable under any circumstance and that removing the tilt is the ONLY acceptable option?

What? No, I'm not anti-keystoning. I'm saying I'm against the often suggested alternative of tilting the screen itself to avoid it.

Keystoning is really nasty, but the higher and higher the resolution of the projector, the less objectionable the aliasing you're going to get. However, with something as small as a digital projector, with the lens options that most have, including lens offset, there really is no reason to be using electronic keystone adjustment, and I would try my absolute best to avoid having to use it. That being said, it certainly doesn't cost you anything to fiddle around with your display and see how much it bothers you with the content you're viewing.

In my previous set up I had the screen tilted some to avoid keystoning. Maybe an inch or two further out on the bottom on 92" screen. The tilt was not noticable at all. I think the only drawback is you may not get as uniform focus, but I was using a Panny 300U which isn't the sharpest to begin with. I now have the same projector projecting on a wall in a 56" screen. I reused the same ceiling mount and I had to tilt the projector resulting in a trapazodal image. I am using a decent amount of digital keystoning and the image has degraded very slightly. It is really difficult to see the difference between the keystoned and non-keystoned image. However it is obvious that I am not using the full LCD display if I bring up any of the full panel test images.

You will just need to try both scenerios and see what difference you see with your set up.

Does the keystoning really bother you? If you can see it and find it annoying, fix it. If it only bothers you because you know it's there, stop obsessing, relax and enjoy your system.

Correcting the problem digitally in your projector will result in some image quality reduction, but not to the degree that it will be really obvious.

I guess it comes down to which slight imperfection you prefer to live with.

If the tilt required is small, I would rather tilt. I agree if severe tilting is required which means you would also have to use excessive keystone correction then you probably picked a projector that does not meet your needs.

I am hoping that the next gen of 1080p DLP offer more options like short throw, lens shift or lower vertical offsets.

If the HD80 did not have a 36% offset I would have purchased this unit.

projectiondesign Action! M25 will have vert. offset of 125%.

OK, I decided to try tilting the screen. It needed to come out 2.5 inches from the bottom (104 diagonal, which means about 53" tall including border, which makes the tilt approximately 5%).

Tilt is noticeable when the room lights are on, but we watched a movie and after a few minutes of dwelling on it I got absorbed in the movie and forgot about the tilt. (Actually, I also started dwelling on the artifacts my older dvd player is putting out, but that's another story).

Will stay with this for at least a few more movies and see if it presents any issues. Based on the responses so far I am not so concerned about KS that much any more, but on some level of logic am inclined to avoid it. Maybe because, as an audiophile, I prefer analog in general, or at least undoctored digital, and have observed first-hand that certain digital operations don't sit well with the human senses.

I do not plan on any computer viewing on this system, and in fact not much of anything but movies for now, perhaps some tv down the road if the room starts getting more use.

Thanks for responses so far and feel free to add to the discussion!