Welcome to BigScreenBiz.com

We have a straight screen and I have recently thinking of what the benifits of a curved screen would be. Will I need any special equipment to show the movies on a curved screen? Would I have to change my projection booth in any way? Comments on the subject are welcome.

If you have a matte white (gain=1) screen, it should be installed FLAT. If you have a gain screen, the screen should be curved and tilted to reflect the light back to the center of the seating area. Ideally, "ray tracing" should be used to optimize the curve and tilt. Or the guidelines in SMPTE Recommended Practice RP95 should be followed.

In effect, a gain screen should be treated like a mirror, where each part of the screen is curved/tilted to reflect the light back to the center of the audience. In fact, you can verify the curve by using a small mirror at various points on the screen. When you reflect the projector's light back to the center of the seating area, the mirror should be parallel to the screen's surface.

When a gain screen is installed FLAT, it will be difficult to get good illumination uniformity.

---

John P. Pytlak, Senior Technical Specialist
Customer Technical Services
Entertainment Imaging
Research Labs, Building 69, Room 7525A
Eastman Kodak Company
Rochester, NY 14650-1922
Telephone: 585-477-5325 Cell: 585-781-4036 Fax: 585-722-7243
E-Mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Website: http://www.kodak.com/go/motion

Also If you have a steep downward angle to your projection younwill experience some curvature of horizon lines

Hi John - Could you give me a definition of "ray tracing" pleases.

"Ray Tracing" is something you've probably done in high school physics. Remember when you predicted the way light would refract or reflect? Angle of reflection = Angle of Incidence? Effectively, ray tracing imagines a gain screen to be a mirror, so you can predict where most of the projector's light hitting any point on the surface will be reflected to.
http://www.physics.fsu.edu/courses/summer00/phy2054c/phy2054c/hw/Ch23/ch23.htm
http://www.glenbrook.k12.il.us/gbssci/phys/rpsolns/rpu14sol.html
http://astrosun.tn.cornell.edu/courses/a525/lectures/A525_10(Ray%20Tracing).pdf

---

John P. Pytlak, Senior Technical Specialist
Customer Technical Services
Entertainment Imaging
Research Labs, Building 69, Room 7525A
Eastman Kodak Company
Rochester, NY 14650-1922
Telephone: 585-477-5325 Cell: 585-781-4036 Fax: 585-722-7243
E-Mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Website: http://www.kodak.com/go/motion