Comparison of currently AVAILABLE Stereo Screens

Testing was visual and the results are shown below.  A small sample (about 8x10 inches) of the screen being tested was taped over a Da-Lite Wonderlite screen.  Four pictures were taken: 

1. On axis of reflected light to measure comparative brightness (Bright is good)

2. On axis of cross-polarized light to measure extinction (Dark is good)

3. Off axis of reflected light (26°, distance away from center = 1/2 distance to the screen)

4. Off axis of cross-polarized light

The Da-Lite Wonderlite screen was picked for the comparison because this screen represents a proven performer.  I would be extremely happy to own a screen with similar characteristics.  Both the large NSA and PSA screens are made of this material.  Note: For the subjective ratings below, this screen is rated B.

The results are shown below, together with a picture of the texture of the screen.  A summary of the results and comments follows.  Overall, I would say that the Stewart screen appears to be the best, followed by the Trivision and the Reel 3-D screen.  The "improved" Da-Lite screen is considerably improved (compared to the no. 5 screen in the previous study.  Still it is a bit behind the Wonderlite screen in that the brightness drops off center.  Extinction (which in my opinion is more important) remains good on and off center.

Screen	Center (top row) - Off Center (bottom Row)
	Brightness (bright is better)	Extinction (Dark is better)
9 - NEW DA-LITE Good center brightness and extinction. Brightness falls off center. Extinction remains good. Subjective Rating: C A bit worse than Wonderlite, mainly because of drop of brightness off center, but much better than the material tested earlier!
10 - REEL 3-D Good center brightness. Better off-center brightness (due to lenticular texture) Good on and off-center extinction. Subjective Rating: B As good as Wonderlite with extra benefit of increased off-center brightness
11 - STUDIO 3D A bit dimmer both on and off center Good extinction on and off center Subjective Rating: C A bit worse than Wonderlite due to lower brightness
12 - TRIVISION Better center and off center brightness - some tendency for hot spots Good center and better off-center extinction Subjective Rating: B+ Marginally better than Wonderlite due to extra brightness
14 - HURLEY GLO Brighter on and off center Worse extinction on and off center Subjective Rating: C Good brightness but extinction does not match Wonderlite
14 - HURLEY SILVER LENTICULAR Dimmer on and off center Worse extinction on and off center Subjective Rating: D Less bright and less extinction than Wonderlite
15 - STEWART SILVER 3D Brighter on and off center Better extinction on and off center (best extinction of all screens!) Subjective Rating: A Better than Wonderlite in both brightness and extinction	Brighter	Better Extinction
	Brighter	Better Extinction

Subjective Ratings

About the ratings:  Anything with a rating from A to D can be used for stereo projection in my opinion.  The rating of D is given to the Da-Lite screen no. 7 in the previous study.  When I used this screen, I did not notice any difference in brightness but I became aware of a bit more ghosting than usual.  To show the difference between A and D, I put the two Da-Lite screens next to each other and took the pictures below. The Wonderlite screen (no. 6 in previous study) is on the left while screen no. 7 ("My Da-Lite) on the right.  It is clear that the Wonderlite screen is brighter and shows better extinction. 

Brightness (Bright is better)	Extinction (dark is better)

Given that the Wonderlite material is a proven performer and gets a rating of B, anything with a rating of B and higher is highly recommended.  Rating of C is acceptable.  D is the limit of acceptability. 

Screen Orientation

Occasionally people wonder if the screen is oriented correctly for best performance.  Only if the screen shows some directionality in the texture, orientation is important.  Most screens do not show such directionality.  For those that do show directionality, I found that it is only the brightness off-center that is affected (not the extinction).  Consider the Reel 3-D screen that shows coarse lenticular texture.  With the lines oriented horizontally, the screen is considerably dimmer than when oriented the other way, but only when looking at the screen off center:

	Lines vertically	Lines Horizontally
On Center
Off Center

George Themelis

DrT-3d@att.net

Updated: April 2002