 |
|
| Dimension |
9 x 22 x 9 cm |
| Weight |
3 Kgs |
| Focal ratios |
f/5 to f/300 |
| Control |
from PC |
| Software |
Sensoft |
|
|
|
|
Puntino is a wavefront sensor based on the Shack-Hartmann principle that can be used to test a single focal ratio telescope or optical element. Puntino is in regular use at the 3.5m Apache Point telescope in New Mexico, USA, at the 1m FAN telescope of the University of Virginia, USA, the 2.3m VBT telescope of the Kavalur Observatory, Indian Institute of Astrophysics, Bangalore, India, the 2m HIROT telescope of the Indian Institute of Astrophysics, Bangalore, India and the 2m MAGNUM telescope of the University of Tokyo.
Puntino wavefront sensor is a very compact instrument (the dimensions vary according to the focal ratio) and can be used at the telescope, both as an off-line as well as an on-line device (for active optics). It can also be used in the lab to test any optical element.
Puntino wavefront sensor has two CCDs, one for obtaining the SH image, and the other to obtain the star. The 2nd CCD can be used to obtain pupil images of the mirrors (or lenses). This gives additional information of the optics, as the following image of a 1.9m mirror shows:
The zones leftover from the polishing on the surface of the mirror are clearly seen. Also, the pupil is not circular, due to the fact that the lateral
supports were not properly adjusted, and were pushing on the mirror. The bright spots are due to air-currents on the surface of the mirror. The hole in
the middle is the shadow of the secondary mirror, and the cross the shadow of the spiders holding the secondary mirror.
|
|
|
