Point! Shoot!

Pointing the tube thingy is easy - but getting it to point at something that you actually want to view is, well another matter entirely.

I hadn't realised just how akward it would be to aim even my little scope and have spent plenty much time flailing around the sky trying to get the target of my attention into the FOV. This is not helped by being unfamiliar with what one actually sees in that little circle of darkeness - you line it up with what you think will be a familiar sight and then peer into the eyepiece only to be confuddled by something quite different!

I realise now that my first attempt at alignment for the GOTO was a huge and possibly uncharacteristic stroke of dumb luck - even with the 5 minutes (quite literally) or so it took me to finaly get a bead on my second target (Rigel) which I eventually captured with the help of my neighbour's roof guttering!

On a more recent attempt I was out earlier in the evening before Orion was up sufficiently and elected to try Capella as No 2 - eventually giving up after being unable to be be sure that I had it in the FOV - the unfamiliarity I mentioned before - I just wasn't sufficiently familiar with that patch of sky as seen through the scope and although I am sure I actually did identify Capella it was much less bright to me than with the naked eye and so I did not believe it was the right star - so basically my patence was exhausted and I decided just to roughly wave the tube around by hand. As it happens I had just joined up with the Central Scotland Observing Group (nice bunch) and given that it was a nice night headed out to meet them at one of their dark haunts - alas we didnt get much actual observing done but that is another story!

So fed up with the futility of sighting along the top, the sides and underneath the tube, and not a little impatient I decided to get one of those red dot finder thingies - rationalising that It would help no end in banishing the fruitless waving around of the scope.

My first thought was to get a Telrad, but while reading some reviews I noted a comment about its size - accompanied by a nice illustrative photo - thank goodness I did before flashing the plastic. Checking the dimesnions I quickly realised that it might actually be a tad bulky for my baby ETX. On checking the dimensions (which were not easy to track down I might add - note to telrad) I realised that the Telrad would almost certainly foul the objective sleeve on my tube preventing proper operation of the focus - scratch the telrad.

Anyways after some further jiggery pokery I settled on a Revelation MRF and sat back to wait delivery of the toy. The MRF was suitable for attachement to scopes 6" up as I recall so I ordered from a different source a 'universal' mounting plate suitable for scopes of 80mm up (which proved to be quite prescient as it happens).

After a few days the post dropped through the door and excitedly I ripped open the parcel to get at the shiny inside - and there it was in all its dark milled glory a lovely looking HUD for a scope - not too big and light enough not to unbalance my little baby when mounted over the pivot but, - why does there always have to be a but?, there was something odd about the stem for attaching it to the scope... The dovetail on the top of the stem mated well enough with the MRF but there seemed no way of attaching the stem itself to the scope - the base of the stem being a hollow prism with a tab projecting down from one end (see pic). And there were no mounting holes that I could use to attach it to the flat plate adapter I had ordered either - harrumph.

I suppose I could buy some double sided sticky foam and banjo the stem directly to the scope - but there wasn't enough surface area on the bottom to be confident it would stay fixed - even if I filled the darn thing with epoxy or some such, and anyway the base of the stem was too flat for the curvature of the scope (and would still have been even if the scope was bigger) plus there was no way I was going to drill any holes in the side of my precious either! What to do? Well the adapter plate duly arrived the following day which at least looked like it would fit to the tube happily with the swanky foam adhesive strips provided! And the flat top would permit the base of the stem a flat surface to be stuck too if nothing else. However all was not lost a quick e-mail and phone call to Ted at Telescope house revealed that all of their stock was also missing the base that should sit between the MRF stem and the OTA so a base plate was soon winging its way to me. Phew - I really thought I might have ended up with a right old mess going on there.

So a couple of days later the shoe duly arrived and anxiously I put all the parts together for the first time - the stem mated to the MRF, the shoe screwed happily to the adapter plate and the stem securely fitted to the shoe - relief all round. Now all I had to do was stick it to the scope and get it aligned. Alas I had decorating to do!

Anyway a couple of days ago, painting dutifully finished, I finally got the time to attach the MRF and try to align it with the scope - sensibly I thought, I decided to try and hold it in place and roughly align it before pulling the strips off the foam patches and bonding it irrevocably to the ETX. It turned out to be a little trickier than I anticipated not least cos the Alt clutch on the scope didn't grip well enough to prevent some movement while I was turning the allen screws to adjust the position fo the red dot - sheesh! Anyway after one aborted attempt, thinking I had it and finally committing to sticking the thing to the tube I found that I could not get the dot on the target telphone pole within the travel available on the screws. I resorted to prising the adapter off the tube and sticking it on in another location closer to the centre line. With bated breath I tried again to align the dot and still it seemed I couldn't get enough travel on the grub screws! Fortunatley after a few more minutes of fiddling I managed to get the spot on the spot as it were - I had been too timid with the allen key and found that there was still some room to tighten up the grubs further - relief. A bit more adjustement for progressively more distant targets finally picking a radio tower about 3 miles distant and I reckoned that it was about as finely adjusted as I was going to get it - all I had to do now was wait for some darkness and a few twinkly things to test it out on.

Later on in the evening I spotted a few breaks in the clouds and a clear run at U-Maj, so I hurriedly assembled the telescope on its tripod - fitted an EP powered it and the MRF up and expectantly slewed to aim at Mizar/Alcor. The moment of truth had arrived: and there they were in all their finery - pretty much slap bang in the middle of the FOV or at least as near as makes no difference! Result! A couple of other aims and checks later and I was really chuffed - now I am confident that I can pop the scope on my target of choice with minimal fuss - whether to align the GOTO or for star-hopping/manual-looking! and can't wait for some clear skies to play with it again - of course those will be aeons away I am sure - well at least I can play with stellarium to get more familiar with some of my favoured targets. I learned from another place how to add telrad reticules to a custom scope in stellarium but also more useful from my perspective how to change the FOV to use a circular mask simulating a scope and - even better - discovered the settings to reverse the FOV so that I can get a reasonable fascimile of a real scope - now I have no excuse not to familiarise myself with the views I should actually expect through the eyepiece which will doubtless come in handy for identifying targets more accurately.

All in all a good outcome, even with the tribulations!

Gawd knows what I am going to find to write about next time! :-)