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Last chance at M81 and 82


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Hi folks.

Well I decided to spend yesterday readjusting my complete set up.

After the slight accident of running the scope into the observatory roof I was getting severe problems with the tracking and the mount was making some horrible groaning and grinding noises.

I stripped off the top of the mount, cleaned up and reseated the bearings.

I then spent a good half of an hour balancing the set up.

After much discussion during the week on Polar alignment in the chat box I decided to check mine.

I haven't done this for the best part of a year so I figured it was due.

To my horror it was miles out.

So I spent the best part of two hours re-aligning and centring the Polar scope in my mount using the neighbours TV Ariel.

First job when it got dark was to Polar align.

The difference it has made is incredible.

When guiding the Dec adjustments PHD has to use has dropped from an average of 200 to 250 pulses South down to 20 to 40 pulses North.

The net result is that PHD has to make substantially less corrections and the results in the subs is quite noticeable.

I now have zero star trailing.

I do have a very slight drift to the South which I will correct with time.

By slight I mean when watching the subs come in using BYE in full frame mode, the image drifted one quarter of an alignment box in 2 hours.

I decided to grab the last chance to get M81 and 82 before they disappear below the large hedge that runs along side the Northern edge of my garden.

Setting up on the target I found the brilliant moon was causing grief as it was washing out the stars making guiding interesting to say the least.

After several attempts and much adjustment of the guide scope I found myself a decent guide star and set the imaging off and running.

Due to the low position of the targets I only managed to collect 15 subs of 120 seconds at ISO 800.

I put these into DSS along with 11 Darks and 11 Flats.

When DSS had done its stuff I decided to do a pre-process of the image using the tools in DSS.

This is the result.

I then saved this image and opened it in Photo Shop 6.

After a short play with the curves I had produced this image.

A little more work and a bit of cropping gave me a final result of this.



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Nice. Job for 15 subs I must centre my polar scope I have the same drift probs ,what camera do you guide wih graham ?,wish I cold get out here bliddy cloud


Thanks Pat.

I guide with my own home made rig.

I mated a Phillips SPC 900 to a Helios 44mm camera lens.

Works perfectly when using PHD.

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Nice result Graham - quite a few details are very discernable in there. Tracking is spot on too - circles right to the edge of the field. :)

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Cheers Mike.

They are now off my list till they come around again.

Either that or the hedge is going to feel the sharp edge of my chainsaw.

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