Sky at Night Magazine

[Aratus]

Unless there is something new happening that I don't know about,

From what I've seen there's not much chance of that!

Don't you believe it. There are always new developments! It is hard to keep up with everything sometimes.

Some people when looking through an SCT are surprised to find that they don't get a doughnut shaped image everytime they look through it! (and of course a Newtonian reflector has much the same problem. ) What actually happens is that normally the 'shadow' is dispersed across the image, and the only effect is that gives a slightly lower contrast. The 'doughnut' also turns up if the telescope is less than focused, and a long exposure of a faint area just gives a field of doughnuts! Specks of dust can also end up as 'dark doughnuts' on your images.

[Graeme1858]

Seems I need to investigate this phenomenon! There's me thinking I had an advanced grasp of optics and then another aspect comes to light! The more you know, the more you find out you don't know! It keeps the hobby interesting.

[Graeme1858]

Third time out last night and the wireless connection has packed up! I did a two star alignment with the hand controller which wasn't spot on but was able to get me to quite a few faint fuzzies. I've retrieved the zoom from storage so that speeds things up a lot. My view where we are at the moment is due south but narrow, so I did get to see; Albierio again, M57 the Ring nebular again, M27 the dumbell for the first time and the M56, M15 and M2 globular clusters, Then spent a long time on Saturn and then Mars when it came up over the neighbour's roof.