Projector keystone

[Jsgregg]

So, I want to run something by all of you and get some input. I would like to know how many of you are using the keystone feature on your projectors in your simulator setup. This is what I would like to know:

1) What projector are you using?
2) What resolution are you running?
3) Are you using the keystone adjustment?
4) What image size are you projecting to?

I'll go first. I am using an Optoma GT760 which I am running at 1280x800 (16:10). I am projecting to 12'W x 7.5'H. The projector has enough vertical offset that I do not have to currently use the keystone feature. I bought a PJ that had vertical offset so that I would not have to use the keystone feature. I do not know that this was at all necessary. I had read that using keystone causes a loss of some resolution, but I have not personal experience with this and do not know whether I would even notice it or not.

Please chime in and share your experience.

[Dax]

I believe that using keystone could cause image distortion and likely more artifacts in the image. If at all possible, I believe you should avoid having to do keystone correction.

[Jsgregg]

Hey Dax, if it's no trouble would you mind answering the above questions? Just trying to tap into this great database with information that might help others.

Everybody else, please chime in! This is a great site with great information!

[Dax]

I was going to hold off posting until I got my screen installed, just waiting on delivery and hope it should be in this week. However,

My projector is the Benq 1080st

Have not decided if I will set up in 16:9 or 4:3 yet, but will try both

I will not use keystone adjustment. I have will try my hardest to set it up to spec and have a ceiling mount from Benq that should help me get where I need to in terms of height adjustment.

In 4:3, my image would be about 12' by 9'

I tested the projector in my theatre room a few times in different light conditions and so far it seems to perform pretty good.

[syhlif32]

Best to avoid keystone all together by placing the projector at the right height.
Have my projector just a tad higher to avoid shadows on the screen and then tilted the screen back about 3 degrees.

Works great noticed the angle the first day but nobody else sees it. Due to the angle back I get a little more light reflected back compared to a vertical screen as a side bonus.

I prefer the 16:10 format to 16:9 but will not go back to a 1280 x 800 after using a 1920 X 1080. Waiting for sun $1K 1920 X 1200 projectors
10 1/2' is as wide I like to see with 1920. Would not enjoy 12' wide on a 1280 projector at all.

[torreypines]

Best to avoid keystone all together by placing the projector at the right height.
Have my projector just a tad higher to avoid shadows on the screen and then tilted the screen back about 3 degrees.

Works great noticed the angle the first day but nobody else sees it. Due to the angle back I get a little more light reflected back compared to a vertical screen as a side bonus.

I prefer the 16:10 format to 16:9 but will not go back to a 1280 x 800 after using a 1920 X 1080. Waiting for sun $1K 1920 X 1200 projectors
10 1/2' is as wide I like to see with 1920. Would not enjoy 12' wide on a 1280 projector at all.

Why wouldn't you use the higher resolution
projector with the wider screen? Thanks.

[DGThread]

I bought a Epson 4030 for dirt cheap so I might stick with 16:9, I may however go taller if the picture is still nice on 16:10. currently building my PC so I wont fully know till then. I ran some of these Creative Golf 3D videos to prepare for the look I will be getting. I thought 16:9 wouldn't be tall enough but those videos projected on my screen are more than enough to make me smile knowing for what's coming. Still have yet to commit to a sim company as I am waiting semi-patiently for this Skytrak idea. My screen frame is easy to adjust size so I will wait for the software to make my final choice on ratio/screen.

I am using lens shift and a bit of keystone, still amazed by the picture! Don't let people tell you it's junk if you use it, I am pretty picky and I dont notice all that much. I read on AVS forums people say its almost un watchable, NOT TRUE at all. I am also not planning on using this projector for anything other than golf. I find massive screens give me a head ache during fast action scenes, golf is perfect for it.

BTW, anyone ever try putting in 3D? lol

[throttle]

I have an Epson 730HD and run it in 16:10. My screen is a PR-20 that is 10'X9.5'. I noticed no difference between keystone and non, so I mounted it higher (11 foot ceiling/keystoned it) to avoid shadows. Works great for me! Don't buy into the hype unless you have a really good screen and have perfect vision!. Others may notices a difference on a better screen than mine but I m sure it wont effect your score!

[schaedj]

I have a Proxima DP 9280 Projector. I'm using it on a 10x10 screen (The size of my "cage") with the Resolution set at 1024x768 and aspect ratio to 4x3 - The projector goes higher, but the LCD chips are native 1024x768, so higher res just means that the pixels are "interpolated", not that you are getting a true higher res image. I used this projector because a) I had it, b) it has a motorized vertical lens shift, and c) it's 4500 Lumens, so light control is not as big of an issue. At the moment, I'm using digital Horizontal Keystone correction, because the unit is actually sitting on a table off to the side of my cage. It is true that you lose resolution with keystone correction. The way that a projector "Corrects" for keystone is by turning off the pixels on the wider sides of the image to true up the frame and expanding / compressing the remaining pixels to fit the image. e.g., if the bottom is 10% wider than the top at 1024, the top of the image will be displayed at 1024 and the bottom will be displayed at 922, with the data from the 1024 pixels compressed across the 922. This means that the lower you go on the image, the less detail you will be able to see. However, if you are like me, with aging vision, you most likely won't be able to tell the difference and the experience will still be "immersive" - which has a lot more to do with the rest of your setup than the pixel resolution on your system. As far as the 16:9 vs 16:10 vs 4:3 debate goes, I prefer to use the image ratio which maximizes the pixel density / screen fill (In my case 4:3, since my screen is nearly square) - Since the simulator will adjust the content to the available screen size, you aren't truly losing resolution and the detail is no greater. If you have a projector that will fill the screen at 1280x1024 in 4:3 or 3/4 of the screen at 1280x800, all that using 16:9 does is lose you 1/4 of your image. If, on the other hand, you have a projector that fills the screen at 1920x1080, it makes no sense to drop down to 1280x1024 to preserve a 4:3 image and leave black bars on the side of the image. A widescreen image generally feels more "immersive" because of the peripheral effect, but that only applies if you don't have to reduce the total image size to accomplish it. A 10x6 image is less immersive from the same distance than a 10x8.5 image.