Evaluation of Two Fully Rugged Laptop Computers for the Forest Service
Appendix I—Screen Visibility Tests
Purpose
The screen visibility tests determined whether there were any significant differences in the screen visibility in full sun or in the dark. Viewing laptop screens on a bright, sunny day is difficult. They must be very bright. Some screens have special coatings to make it easier to see details. This is very important to all field users, particularly those in law enforcement, firefighting, and field research. Additionally, law enforcement officers sometimes adjust the screen to very low levels so it does not illuminate their position when they are using the laptop in the dark.
Equipment
Digital photos were taken with the laptop screen in full sunlight and in a darkroom at both full and lowest intensity. The photos were taken with the laptops in the same position and location so an overlay could show the photo of each screen next to the other. All camera settings were the same for the photos. Two different screen images were photographed for each test. One was a white background with black lettering. The other image was color palette used by photographers to test image color.
Procedure
Outdoor full sun tests: The laptops were set on a table with the screen facing the sun. A camera was set up facing the screen. The laptops were configured so that the screen was at its brightest. The CF-30 screen was set to 1,000 nits and the XR-1 screen was set to its highest brightness (500 nits). A Wordpad document was opened, displaying black lettering on a white background. Photos were taken. Then a color palette was displayed and additional photos were taken.
Indoor tests: The laptops were adjusted so their displays were at the lowest possible setting that still illuminated the screen. This setting would represent someone using the laptop in the dark with minimal display. Photos were taken of the screens displaying black lettering on a white background and of the color palette. The CF-30 laptop's screen was set at 500 nits.
Results
Figure I–1 shows the photos taken outside. It was difficult to take photos that truly reflected the screen's visibility. The CF-30 screen was much brighter than the XR-1 screen, but the CF-30 screen also had a lot of glare. The XR-1's new DynaVue screen had superior color contrast, which made the items on the screen much easier to see. Although the XR- DynaVue screen was not as bright as the CF-30 screen, it had considerably less glare, improving visibility.
I-1—The laptops were compared side-by-side to determine how well the screen
could be seen in direct sunlight. While the CF-30 screen was
brighter,
the XR-1 with the new DynaVue screen had better contrast and less glare,
making it easier to view.
Figure I–2 shows the photos taken inside with the laptops set to their lowest brightness. The XR-1 screen was much darker than the CF-30 screen (but still readable), an advantage to law enforcement officers.
Figure I–2—The laptops screens were also compared in the dark. It
is important to law
enforcement officers that the screen is not bright enough
to compromise
their position in the
dark. The XR-1 screen was much darker at its lowest setting,
but was still readable.
Conclusions
The XR-1 laptop with the DynaVue screen was easier to view in full sunlight. Although the XR-1 DynaVue screen was not as bright as the CF-30 screen, the XR-1 DynaVue screen had considerably less glare, improving visibility. The XR-1 screen was also darker when viewed at the lowest brightness setting, an advantage to law enforcement officers who don't want to give away their position while using the laptop in darkness.
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