I can say from personal experience that a Super Cub wingtip
inserted (in flight) into the wing of a Nimbus 3 reduces its
performance to about Ka8 level, not all due to the full rudder
required to fly straight.

Total drag of a sailplane equals AUW divided by L/D, typically
around 25 lbs force (or 120 or so if you insist on SI units). Go-Pro
Cameras aren't very aerodynamic. OK when flying for fun, but not
seriously.

At 22:46 12 January 2015, Steve Leonard wrote:
Put enough cameras on, Bruno, and the plane may glide
backwards because of
=
all the drag! Want serious glide degradation, you needed to talk
with
Osca=
r Boesch about carrying an early I-Max camera on his AS-W15.
Pictures in
a=
back issue of SOARING. Oscar left us in 2012.