Mwahaha - first attempt at imaging! (some useful observations)

[NickK]

Well I've just spent the last couple of hours playing around with imaging for the first time. I thought I'd put some notes down for others that are considering starting imaging.

My equipment for this: Vixen A80Mf, Porta mount and a ATIK 16ic. (oh I can hear the sniggers already)

Oh ye fools that wish to tread this path...

Focus. Focus! Fo$%#. Oh.. did I say focus?

So you have the camera plugged in.. finding the focus point is hard for the first time.. expect a good 1/2 hour or so. The fact that you do not have an eyepiece attached and the slow rate of image refresh makes it hard work. I eventually put an eyepiece in and then focused. Only to find the focuser at full extension (which makes the CofG fall back).

Success - 6mm EP focused and put the camera in instead of T-screwing in.. with a little bit of twiddling and I managed to get a star focused. Having a dual speed focuser will make things far easier.

Things would be a little simpler with a flip mirror too.

Ooopfh sir - just one sir?

The star, now focused then precedes to take a good sized chunk of the sensor image real-estate. I didn't think it would be _that_ large! Perhaps a focal reducer would help reduce the size and increase the brightness overall.. food for thought... use a calculator to check the size of the things you wish to image and then have a play with focal length.

I can see that it's edges are lovely and sharp with zero aberration of the star 'colours' (blur in the mono image). A good sign

lines and lines and lines and lines and...

Having a manual mount - this was expected. Any real exposure for anything other than a bright target (1 second+) will result in drift lines for the stars. Add to this mount stability wobble making some interesting abstract masterpieces - O I'm starting to go green at those with a pier topped my some over engineered elbow joint..

I think people have a initial priority for astrophotography wrong:

1. Clear skies, location...

2. A steady hand to guide by (ie pier/tripod stability & the accuracy of the mount)

3. The scope(s) and cameras to see by.

Which is like good espresso: 1) Good freshly roasted coffee beans (roasted 1-2 days before), 2) the best flat burr grinder you can buy afford, 3) the coffee extraction device last... but I digress.

The blighters (stars) move quick.. most unsporting! Just when you are getting comfortable the image is blurred.. foc? no.... looking up you can now see that you're imaging through a set of trees.. planning prevents pish-poor performance. It's worth picking a target that will be available for a long duration rather than one at low declination.. preferably one that an exposure will not end in the trees/telephone mast/a.n.other random object.

..Foooocuuuusss...

Also I managed to knock the telescope out of focus - the A80Mf has a focal lock screw.. now I know why it's useful! How can one screw alleviate so many problems.

So that's an awesome image

Err..

Well they say that 99% of the image appears at processing.. and to get that processing requires images that are stable, without lines and in focus from a tracking mount.

I have put my imaging DIY mount on hold as the friend with the workshop and welder is sprinting to get his renovations finished before his wife gives birth. However that gives me time to have a think further but in the meantime I'm now considering purchasing a Vixen Sphinx SWD mount (even if it's overkill initially) before adding the VC200L later than originally planned. The load capacity will cope with both telescopes.

With AOSX (my ASCOM-type of framework for Apple Macs) progressing towards it's initial release, it would be easy to add support for the SWD in addition to the ATIK.. but that will have to wait until my contract renewal is sorted. Now if only i could persuade Vixen to loan me an SWD *wink* *wink* (ok it was worth a try!)

Lastly.. it's probably worth attempting all this in the warm through a window initially. There's lots of equipment, lots of experimenting and certainly would result in cold fingers, lost equipment and probably running out of battery.

So I hope that others may learn from my inane ramblings before they place their first foot on the path of ruin too.