Arcturus from 25/4/09

[Deneb]

I took these shots of Arcturus, 1st pic untouched, 2nd stacked in DSS 10x 10secs/ISO 1600 in prime focus with a SW200P & a 450D, there appears to be some wobble on the diffraction spikes - is this normal ? :

[Tim]

Beautiful shot. The spikes do that when the vanes of the spider are not quite square to each other.

[Deneb]

thanks TJ, Just a stupid Question - whats the best way of adjusting the vanes of the Spider, without doing any damage to it ?