2007-03-21

No spots or other marks visible on the Sun.

I went out with my Canon EOS 400D and set it up on a tripod and ran off a series of shots. Given how bright the Moon and Venus were I didn't need to use very long expopsures. Annoyingly I appear to have got the focus slightly wrong (I do find it tricky to manually focus the kit lens for astrophotography work

I took 12 images in all but the best of the bunch appears to be this one:

While it gives a reasonable idea of how the Moon and Venus looked it's nowhere near as crisp as it should be. I can see I need to work some more on manual focusing for astronomical photography.

I started out by getting Saturn lined up in the 130M using the 25mm eyepiece. I then switched to the 10mm eyepiece. The image wasn't too bad — a little unsteady and a little soft but it was possible to make out the shadow of the rings on the planet and also the shadow of the planet on the rings.

Next I added the Sky-Watcher supplied barlow lens and had a look at the image with that. As has always been the case I found it difficult to find good focus and the image was very soft to the point of being unusable. I then switched to the new barlow. Focus was a lot easier to find and, while the image wasn't fully crisp, it appeared to be a huge improvement over the Sky-Watcher barlow.

After comparing them a little more I came to the conclusion that the new barlow would, without a doubt, replace the old one in my lens box. It was a very obvious improvement.

I then tried the new barlow with the 6mm eyepiece. As I expected, the image was rather dull and rather soft but it was obviously much better than with the old barlow. I've seen worse views of Saturn at lower magnifications before now.

Having tested with the 130M I decided to give the new barlow lens a quick test when used in the 905. The main point of this test was to see how well it worked with the diagonal. The old barlow, which has quite a long barrel, didn't work too well as it tended to bang against the mirror. The new one is rather shorter and looked like it wouldn't suffer from this problem.

Got Saturn lined up in the 905 and then dropped the new barlow into the diagonal (and it was a perfect fit, didn't hit the mirror at all). Using the 10mm eyepiece Saturn looked pretty good. Again, it was a little soft (I suspect much of this was down to the state of the atmosphere this evening) but was very acceptable. I also tested with the 6mm eyepiece and, while the image was much darker and softer, it was still better than the worst views I've had in the 130M with the 10mm and the old barlow.

Under ideal conditions I imagine that this new barlow and either 'scope will make for a reasonable combination.

By 22:07 UT it was starting to get very misty and, to make matters worse, smoke from someone's fire was being blown over my garden so, having managed to conduct some quick tests, I decided to call it an evening.