Sunday 8th July 2007

After weeks of cloudy days and rainy evenings, I was desperate to start imaging with the modified SPC900 again. We had family over for a meal and with the evening being dry we sat outside to make the most of this British summer! I couldn’t believe there was not a cloud in the sky, perfect viewing conditions and when the conversation turned to looking at the stars I offered to get the scope out and show everyone the rings of Saturn.

I was too late to get Saturn as it ducked down below the neighbours trees, and my hasty setup made the goto less than accurate. I turned the scope to Jupiter but the modified SPC900 didn’t seem to work well in video mode anymore and the picture was breaking up quite badly. I’d also not collimated the scope for some time so when I did get Jupiter in focus there was very little detail visible.  This was the first time I’d managed to get Jupiter with the 3x barlow and I was very impressed with the size of the image as displayed on the screen, next time I’ll make sure I have the Trust camera handy.

With a full belly and a beer or two inside me I was ready for my bed when our guests left, but as everything was setup I thought I’d make the most of the weather conditions and spend an hour imaging.

 I imaged through the night and only stopped when the sky turned a light blue in the east and dawn was not too far away.  I’d been tracking M31 over the roof of my house when I realized the stars were starting to fade into the lightening sky, so after a quick glance at my watch I thought I’d pack up.  Cor Caroli

 In 5 hours I’d managed to work through a list of Messier objects that I’d prepared for such an occasion and have captured M5, M10, M11, M12,  M13, M51, M53, M57, M81, M82, M92 as well as one of my favourite stars Cor Caroli.

Towards the end of the session I picked out a double star in Hercules and was disappointed to find that I really should have taken the time to line up my optics correctly. The double star appeared as two fuzzy points rather than the pin points I was hoping for. I fetched by 3x barlow and laser collimator and performed a quick primary alignment using the barlowed laser method.  This is very quick and easy and I was kicking myself that I hadn’t done this earlier. If you haven’t tried it do a quick search on Google for Barlowed Laser M57 The Ring NebulaCollimation.

With the primary mirror now pointing in a different direction to where it had been when I aligned the mount, I did another 3 star alignment. What a difference it makes to have everything pointing in the same direction. When I tapped M57 into the hand controller I was amazed to see the Ring Nebula appear just off center on the screen. Awesome. I’d never seen M57 before and had resigned myself to only capturing bright nebula like M42 in Orion.

I’ve got some processing to do now to make the most of the images I captured but a quick look through them seems promising.

I’m not happy with the EQ-6 tracking at the moment, I wasn’t able to capture more than 10 -15 seconds without the stars stretching into ovals so I’ll have to look into how I correct the tracking errors. When I find the answer I’ll post it here.

Update

I’ve just added a Messier Catalogue to the images section, I’ll need to sort out longer exposures before I can fill in the missing M’s.

Click here to see my Messier Catalogue

Update Update

I forgot to say, when I took the mount apart the following morning I found that I hadn’t tightened the bolt that joins the mount to the tripod after I’d adjusted the azimuth alignment. I should be glad the whole lot didn’t fall off the mount rather than worry about a few stretched stars!

Thursday 28th June 2007

First Light

There was a small break in the clouds last night and even though I’d been awake since 3:30am I couldn’t let the opportunity pass me by.

I had a little trouble with goto not being 100% accurate but I put this down to my hurried setup, I was able to find M3 and M13 and of course Jupiter, but it was very close to a bright moon and low in the southern sky which didn’t make the best viewing conditions.

The image above is a single frame of M3 (20 seconds), I’ve not had time to do any fancy post processing and it looks like my collimation is still out. I’ll post more when I have time.

Sunday 3rd June 2007

With light evenings and rain through April and May, the scope hasn’t ventured outside for some time now. This has given me time to think and to appreciate clear evenings when they do occur.

I’ve decided not to build an EQ Platform or other device that would allow me to track with the dobsonian, instead I’m going to take the plunge and invest in an EQ-6 Pro Equatorial Mount and add the dobsonian mount to my wood pile.

Having the EQ-6 Pro will allow me to initially keep planets in the field of view to get more frames with planetary imaging, but this will also allow me to look into long exposure mods to allow me to start catching the elusive deep sky objects. By getting it now I’ll have a few months to familliarize myself with it before the evenings start to shorten and dark nights are with us again.

I’ll post images when I get around to making the purchase and will document the process for those of you who are also looking at re-mounting your dobsonian scope.