It’s always the way, some things are as predictable as, well, the planets I guess. I get the best night for imaging I’ve had for ages, and it’s on a Friday night so I don’t have to get up in the morning, my wife has no complaints,- so I head out and get myself setup. Naturally nothing works properly at all and I end up spending a fruitless night getting no where fast as I attempt to track down all the little problems.
First off the mount is tracking terribly, this one I can only blame myself for. I had remounted the scope in a different configuration the day before, and then re-leveled the mount to insure everything was square. Unfortunately I neglected to realign the mount after and didn’t do it before I started imaging. This combination threw out the tracking and the goto and PHD guiding wasn’t very happy at all.
Once I had everything sort of working I tried to get a bit of imaging going with what I had left of the night, again my own lack of thought kicked me squarely in the nuts. Imaging with a standard DSLR can give very nice results, but as people expect there photos to look exactly like the image we see through our own limited eye sight DSLR cameras have an in built IR filter. If they didn’t have one all our pictures would look red. Unfortunately for the budding astrophotographer using such a tool, pointing it at a faint red nebula and taking pictures is likely to result in disappointment, which is exactly what I did. I knew the scope was in the right spot, the stars matched, but I could see nothing of the nebula! Lesson learnt, one day I may have to get the camera modified.
With the night rolling on I had one last chance of getting some worth while imaging going and swung the scope round to the rapidly rising Jupiter which has now cleared the tree on my southern horizon. Now for planets the weapon of choice is the webcam, so that’s what I decided to try with. I had no trouble finding or centering Jupiter in the webcam, but focus was another matter.
To focus my DSLR I have it at prime focus, directly into the focuser, to focus a 1.25″ eyepiece I have to use a 50mm extension tube. The webcam though, well at prime without the extension it won’t rack out enough, with the extension it won’t rack in enough! So I need a smaller extension tube, something like a 30mm should do it.
So I put a 5mm TMB planetary eyepiece in and just enjoyed a fantastic view of Jupiter and it’s collection of moons instead.
