Short throw projectors project at an EXTREME angle. It requires a 100% flat viewing surface. Any variation due to wrinkles or movement of the screen, measured in fractions of an inch, will distort the image. A bit more and the distortion is very significant.
This image is a lousy example, but all I could find on short notice...https://golfsimulatorforum.com/filedata/fetch?id=134658&d=1511735495
It shows a standard throw projector on a VERY wavy screen. A short throw projector on the same screen would be unviewable. But, on a very slightly wavy screen it would be very noticeable.
As well, because of the extreme angle short throw models use, any movement towards the bottom of the screen would be magnified a great deal.
The issue is most prevalent in ultra short throw models, and then lessens as the projector moves further and further from the screen. I wouldn't go any closer than the Viewsonic 7827HD allows. So, about 10 feet or more would be my minimum.
If you really want to go this route, you would need an extremely good tab-tensioned motorized screen. Expect it in the $1,000 range for entry level and upwards from there, depending on screen size and quality of build.
- Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.