"George Normandin" wrote in message
...
Last year at Stellafane a friend & I found that our CCD'ing laptop
was
annoying nearby visual observers. I would think that "star party
etiquette"
would have to be that bright laptops are not acceptable.

So: How does one use a laptop or other PC at a star party or popular
observing site? Anybody have suggestions on how to cut the screen light
down
to levels acceptable for visual observers? Keep it under a box?

George Normandin
Four stages:
1) Set the screen brightness as low as possible.
2) Select a largely 'red based' colour scheme.
3) Add a darkish filter material over the screen (Rubylith), possibly even
two layers.
4) Add dark 'edges' to the screen, standing about 1"-1.5" above the existing
screen edge.
This last is really the 'critical' one. A lot of LCD screens, 'leak light',
at small angles. Hence you can have your screen set to give a darkish image
when looked at nearly perpendicular to the screen, and bring this down even
lower with filters, but then find that if you look at a shallow angle to the
screen, the light is several times brighter than the actual image. It is the
leakage, that is the real 'pain'. If you sit the screen effectively in the
bottom of a 'tray', this stray light gets massively attenuated (ideally you
wand these edges lined with something like flock).
Some of the modern screens, with very wide 'viewing angles', have less of
this leakage, but more and more designs, conversely, don't let you turn the
intensity down very far...
There are also special filters sold which are meant to block this stray
light, but I have never found them to be as effective as the edges.

Best Wishes