Quote from Sky at Night Magazine SkyGuider review
Imaging results (un-guided):
...We recorded several images at different exposure lengths to see
how well the mount could track: shots longer than 30 minutes could
be taken using the small lens set to 18mm, and even when set to 55mm
we achieved exposures of 20 minutes with pin-sharp stars.
Larger and therefore heavier lenses push the system more, but we
were pleased to be able to capture a 10-minute exposure with only
the slightest hint of trailing using our larger telephoto lens set at 100mm.