When the Ozzie peso was still strong, the lowering price of a decent GEM’s got me interested and then of course prices started blowing out. Seeing the thread here mentioning that http://www.nvt.com.au/ in Perth was still supplying stock at around the $1500 price point I thought why not (now the cheapest I now see is over $1800). Quick call to NVT and the mount is ordered.
As I was now committed to the mount was time to start looking at how to get the 12” Newt onto it. This was NOT going to be an easy (or cheap rather – std rings stop for about the 10” newt tubes) exercise so I quickly knocked something up that would do the job (cheap as – pics in another thread) and then just had to wait for the mount.
Arrives via AustPost and as I was at home when it arrived I quickly opened it all up to see what I have – all looks good. Have a quick look (set it up etc.) but didn’t really have a play (like switch it on – more on this later) as I knew that I would need some more counter weights so it wasn’t until the next day that I was able to get some more weights (2 x 5kg from Kmart or similar and I just made some temp sleeves to reduce the inner circle size). Well the weather in Brissy over the last few weeks has not been great so on the first chance I get I go to set up the mount and scope.
Well for some reason I thought the 12” Newt OTA was 17-18Kg (no idea where I got that idea from – a quick Google seems to suggest it is more like 25kg – anyone know the exact weight?) so that’s why I had gotten the extra 10kg. So after getting everything setup I start to balance things and realize that I need more weight. Bugger!! Down it all comes (I still haven’t put power to the mount). Another trip to the shops and I now have 2x more 5kg weights (better than the Kmart ones – got them from AMart) however I have lost some more days.
This is it finally I am ready to try out the mount. To facilitate setting up I have gotten a cheap compass and made a wooden jig that is fixed to the legs to align them to south. I have marked the mount head and legs to aid that south alignment. I also have an inclinometer (which I used to use on the dob) to set latitude. On goes 30kg of weights and the OTA etc. and I get balance… (does 30kg of counter weights for the 12” Newt sound about right? Seems like a lot).
At this point I would ask how critical is balance? Is near enough good enough? I mean I can easily move the mount in RA and leave it and it doesn’t move but I am sure that there is some latitude there (i.e. a couple of kg over or under would seem to do be roughly the same – i.e. the mount will be easily moved to a position and not move) thus the question how critical was exact balance? I know perfect balance is optimal but is a little bit of latitude OK?
….now we are all ready to go. Lets plug in the mount and …….Hmmmmm hang on we have a power cord for a cigarette lighter but no mains adaptor. WTF I just spent ~$1500 on a mount and they don’t even give me a real means to power it. Oh well no problem I thought I have a hundred power adaptors lying around so off I go. I did have a couple of DC ones but nothing, nadda, zip then I do get one that powers up the mount and slews to the first alignment star…..but then nothing when I press the buttons (now at this stage I know I have issues with power and it seems you are supposed to have 2amps (mine much less) so I am putting all my issues done to power source however in hind sight the fact that the scope didn’t move is possibly attributed to the rate being 2 (seen a few others caught up by this trap on the forums as well so I don’t feel too bad) where as rate of 9 is easy to see the movement (where as at rate 2 it doesn’t appear to moving in say the finderscope). Anyway I pack up frustrated that another night is going to pass me by (it is at this stage I realize I should have powered up the mount on day 1 to check it….).
Off to Jaycar and some $30 later I have a decent power supply for mains (never did go back and check the 1000 odd adaptor once I realized I should have changed the rate). Plenty more days go by due to the weather…..
Another try for first light presents itself….
Now in the meantime I have made myself a bracket so I can mount the D90 on the mount so was keen to try out some long exposure wide angle stuff however Nikon in their infinite wisdom have decided that the bulb setting can only be used with a IR remote or super expensive cable. Without these things I am limited to 30 seconds (why the software couldn’t take longer than 30 seconds via the PC I have no idea). Nikon could probably produce these remotes for cents and include them with the camera (after all you do pay a reasonable sum for the camera) but NO, they want to sell them separately for a large profit and gouge their consumer base (hell they even want you to pay for the remote software (fortunately it can be found easily enough).Grrrrrrrrrrrrrrrr anyway rant off back to the mount story.
All set to go. Just did rough alignment powered up and then did a 3 star alignment then tried some gotos getting the object into the FOV with think a 15 or 25mm EP. Woohoo – however I realize that as my back yard is sloped I really can’t use the scope as is (try standing on a chair that is at 20 odd deg whilst trying to look into an EP). Probably should have thought that I needed a level area but anyway was enough for a quick try but I wasn’t going to persevere with the site as is but thought well how about I thro the D90 and take a couple of shots. Took a few (limited to the 30 seconds) and I have included one of the better ones as an example (etawide). One thing I did notice that when I did another 3 star alignment the mount seems to have forgotten the previous adjustments (as the 3 star alignment was basically the same as the first in the adjustments I needed to make whereas I assumed next time it would almost be spot on).
So I have site issues. My temp solution is rather than cut a level area out (will make a more permanent area at some stage) I have just dug a pit for the high side leg. Whilst this works and is manageable (just – still a pain if you do need to get up to the eyepiece) the second session was also limited due to site difficulties. Definitely need a proper solution which might be build a decking area around the mount. Anyway the wide angle stuff makes me want to get the camera attached to directly to the scope so with the bad weather that is now my focus for the next session.
Now as I know I will need to use the Barlow to bring the D90 into focus I go out and just get a T Ring for the Nikon. Didn’t bother with a T Adaptor because I thought that the T thread and 2” thread was the same (hell it’s only a few mm different – it looked the same – I know better) so I thought I could just attach the T Ring to the Barlow – Wrong!!. Back to get a T Ring adaptor. Weather is no good (it would have been OK the previous night but I couldn’t use the camera of course because I needed the adaptor) so I try the D90 just on the Dob base with the barlow…..Success!! Woohoo….can focus on the moon so I am good to go for when the weather does improve…but of course it’s cloudy for days.
Whilst waiting I used http://www.newastro.com/book_new/camera_app.php to setup scope and camera etc. (including Barlow x2) to get an idea of some potential image targets for this combo (works well with the expanded image set). Loaded these into a list in Starry Night Pro and I was set to go. I haven’t used the mount with the lappy and didn’t intend to on the first night – just wanted to use the hand controller whilst the D90 is controlled from the PC.
Last night was the night. Had dinner and then setup the scope to cool whilst I did family stuff. When the kids were in bed I went out to attach everything. Didn’t bother to check collimation (had been awhile but I wasn’t worried – mission was just to see if I could take a couple of shots with the D90 through the scope) and again did the rough alignment (actually I haven’t even looked in the polar scope – would I see anything in regard to the SCP being on 8ks out of Brisbane CBD on the Southside?). Popped in a 25mm EP and did the 3 star align and then did a goto to M42. Looks good – now to pop in the D90.
Got to admit I am still disappointed with how little you can see in LV on the PC even when connected to the scope (the wide angle lenses are worse). No problems with brightest stars of course so focused on one. Now I am yet to get the remote so am limited to 30 second exposures so away I go. First few exposures show not much and some trailing at 30 seconds. Figure polar alignment is probably pretty crappy and it takes me awhile to realize that I had the ISO on like 400. So using higher ISO and less exposure I set about just doing some quick exposures. Have attached a couple of first prime focus shots to show you what I got just having a mess around. Now these are all single frames (stacking and multiple shots etc. can wait awhile) and the next thing I will concentrate on doing proper alignment so I couldn’t even do 30 seconds (these are 10 – 15 seconds) but I thought it was at least a start (the moon one is a composite – the first one I did had better focus but was incomplete – not sure how but I missed a bit of it so this second one at 1/100 seconds will have to do).
I really wanted to try and get some galaxies (as I am yet to see one through the scope) but I got nothing. Now that could have been the goto as I thought I would get something provided I got them on the chip. I was using the 2 second escape thing to recenter objects but I notice you are supposed to hit enter when it confirms where as I might have just been escaping (cause you use escape to navigate back switching between NGC and Messier etc.) so I might have thought I was improving alignment where as I might not have been (it was definatley giving the same error when using goto for a couple of objects). Gives me something to try for when I do sort out good alignment and goto.
All in all for a first night out (with D90 and Scope) I am pretty happy. Next time I set up I will just focus on doing drift alignment and see if I can figure that out and then might try some 30 second exposures. I do like using the PC to view stuff instead of the EP however I would really need a better (high sensitivity) cam to give me something approximating (or better) than my naked eye (or view through the EP) for this to be usable. Last night I could check items in the finder to make sure they were going to be on the chip however this was no good for faint stuff – like the galaxies so I need to sort of good alignment and tracking. Hopefully I can do that and then I can see how the mount performs.
That’s it for now so stay tuned and I will let you know how I went drift aligning (I am right that if you do drift align you don’t need to worry about the polar scope etc?). One observation the hardest part of the whole night was aligning the dam finder with the main scope at the start - that’s damn hard.
it will only get better from here
