At 21:03 30 January 2016, wrote:
Two personal experiences:=20

In one of my clubs, an ASK-13 was painted completely in bright
orange. The
=
only situation where this was really visible was in bright sunlight
when
fl=
ying slightly higher. In all other situations it just looked
gray/black,
ju=
st like any other sailplane.

During one alpine flight, with a green/brown backdrop (no snow)
and with
th=
e sun in the back, I was surprised at seeing a series of white dots
coming
=
in my direction. It was a glider with a series of hi-vis stripes,
approxima=
tely 50 cm wide, taped chordwise every meter or so on the leading
edge.
The=
white was decidedly more visible than the stripes...=20

With a snowy backdrop, bright orange markings are a welcome
plus, but I
pre=
fer large markings at the wingtips rather than numerous small
strips all
ov=
er the sailplane.

I used to fly in a Janus with two classic white strobe lights, one
under
th=
e nose in front of the nosewheel, the other on the back just
behind the
can=
opy. No improvement in visibility in full sunlight, but very visible
when
f=
lying in the shadow of the clouds (cloudstreet, convergence). Not
sure the
=
new "LED" strobes would be as efficient, but certainly worth a try.

I think it is a common finding in this thread that almost nothing
increases the visibility of a glider approaching head on, in fact some
markings may reduce visibility. The frontal area of a modern glider
is so small so with no relative lateral or vertical movement they are
very hard to spot.
There is a way of mitigating the risk and that is to make regular
course changes to induce relative movement, the question then
arises if performance should be sacrificed for safety, I can already
hear howls of anguish at that thought.