As a result of my preparations for conducting some screen captures, I took some time to 'think' about how the projector-screen-viewer function occurs. Because I'm using a CRT, it was natural that the installation presented a nice frame of reference in the form of a free body diagram.
My projector projects at a 11? angle of declination onto the center of the screen. The viewer (me) is looking at the center of the screen from a 11? angle of inclination. Angle of incidence equals angle of reflectance.
When looking at some screen manufacturers' websites, the 'viewing cone' is often expressed as a function of viewing angle vs. screen gain. Almost everyone takes into account of this function in better understanding the seating consequences as it relates to brightness, but this is only a horizontal consideration.
What I have not heard anyone talk about was the screen-gain as a function of angle of inclination. Since I do not know what means of setup a digital projector has--I assume it varies from one digital projector model to the next--I, for my endeavor, only focused on CRT. Thus, I wonder if one realizes that at a >10? of inclination the screen's gain has changed.
With this in mind I took the liberty of looking at the Stewart Studiotek130 screen as its a relatively popular screen for CRT use. When looking at the chart for the screen-gain as a function viewing angle, it appears that the gain is around 1.0 (for a screen rated at 1.30). Unfortunately, I do not know if this gain chart (and others by Draper, Da-Lite, etc.) can be used for vertical angles of inclination by the viewer.
So, now I wonder if many are taking this into consideration when trying to match up a screen-gain to the angle in which they are viewing the screen. I also tried to look at a Stewart product for a negative gain (Grayhawk), but the chart's representation on my monitor was so small that I couldn't read the values on the X-Y axis to make sure I was reporting a relatively accurate interpretation for >10? angle of inclination.
Do many consumers not consider this aspect of screens? How about businesses that are selling the equipment? Installers?
My projector projects at a 11? angle of declination onto the center of the screen. The viewer (me) is looking at the center of the screen from a 11? angle of inclination. Angle of incidence equals angle of reflectance.
When looking at some screen manufacturers' websites, the 'viewing cone' is often expressed as a function of viewing angle vs. screen gain. Almost everyone takes into account of this function in better understanding the seating consequences as it relates to brightness, but this is only a horizontal consideration.
What I have not heard anyone talk about was the screen-gain as a function of angle of inclination. Since I do not know what means of setup a digital projector has--I assume it varies from one digital projector model to the next--I, for my endeavor, only focused on CRT. Thus, I wonder if one realizes that at a >10? of inclination the screen's gain has changed.
With this in mind I took the liberty of looking at the Stewart Studiotek130 screen as its a relatively popular screen for CRT use. When looking at the chart for the screen-gain as a function viewing angle, it appears that the gain is around 1.0 (for a screen rated at 1.30). Unfortunately, I do not know if this gain chart (and others by Draper, Da-Lite, etc.) can be used for vertical angles of inclination by the viewer.
So, now I wonder if many are taking this into consideration when trying to match up a screen-gain to the angle in which they are viewing the screen. I also tried to look at a Stewart product for a negative gain (Grayhawk), but the chart's representation on my monitor was so small that I couldn't read the values on the X-Y axis to make sure I was reporting a relatively accurate interpretation for >10? angle of inclination.
Do many consumers not consider this aspect of screens? How about businesses that are selling the equipment? Installers?