Film-Tech Forum ARCHIVE: Indoor seating distance from screen

This is topic Indoor seating distance from screen in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Barry Floyd (Member # 385) on 12-23-2002, 09:47 AM:

Question here....

I've got a friend of mine who is building a drive-in theatre that will also incorporate "150 indoor seats" on the upper floor of the concessions building. His screen is 100'wide x 39' tall, with a throw of 300' from the concessions/projection building to the screen.

He went out to the site over the weekend and flew tethered balloons at the corners of where the proposed screen will be, and then stood at the location of the building. He was a little concerned with the "optimal viewing" of the screen from the indoor seating section from that 300' distance.

What is the "ideal" distance from the screen to view the picture
from his proposed indoor seating area? His fear is the "big screen" won't appear so big to the patrons seated indoors.

Posted by Pat Moore (Member # 380) on 12-23-2002, 12:03 PM:

Barry;

I like to consider horizontal field of view in determining the relative (or apparent) picture size. I think THX still wants a 36 degree field of view from the last row of an auditorium, as they consider this a "large appearing" image for the auditorium. I'm pretty firmly in Ioan Allen's camp of the "ideal seat" being about two-thirds of the way back in the auditorium and having a 45-50 degree horizontal field of view from that position. This gives a large-appearing image that's very involving to the viewer, without being so close that the picture faults are too obvious.

SMPTE considers "screen heights" to determine the relative image size. It used to be that a position less than 1-1/2 times the screen height away from the screen made the image "large appearing"; 1-1/2 to 3-1/2 times was a "medium appearing" image, and a position greater than 3-1/2 times the height of the screen away from it produced a "small appearing" image.

This all considers a Scope image, constant-height screen.

Pat

Posted by John Pytlak (Member # 331) on 12-24-2002, 06:56 AM:

Seating distance is usually a matter of personal preference. Standard SMPTE 196M specifies a seating distance of 2 to 4 screen heights for review rooms, where image quality is being evaluated. For most 35mm films, I choose to sit at 2 screen heights (e.g., 40 feet away from a 20 x 48 foot "scope" image, or 20 x 37 foot "flat" image. For current digital cinema, I sit a bit further back, as I am personally very sensitive to visibility of pixels and "jaggies" when sitting too close to the [dlp]

screen.