I just dont know......

[ianB (Ian)]

Astro bot, you are also not that far from me, I guess around 100k give or take, when you take the scope out to cool down should I put the dew shield on straight away or leave it off until an hour or so later when I actually use the scope ?
and is it best to have it pointed downwards during this time? ( the reason i ask that is because i read somewhere that this will help in getting rid of dew )
And from your experience have ever needed to use a dew heater in this region of the South East? ( i am in the Caloundra area )

[batema (Mark)]

Hi Ian. I attended a few of those atronomy club meetings at the frog farm near Beerwah years ago and yes a shame it folded. Thank you insurance premiums. There are a few places that you could go a short inland drive from the coast. I know that Ron has open nights that he post on I think the star parties forum. Beautiful area and dark. There is also 10 chain hill but I have not been there as of yet. Also ASTROFEST at camp DUCKADANG near linville in July I think this year.

Mark

[ianB (Ian)]

Thanks Mark, and yes what a shame about that club, maybe it will restart again one day?
and I will indeed try to go up to Ron's when he has another get together.

[Astro_Bot]

Originally Posted by ianB

Astro bot, you are also not that far from me, I guess around 100k give or take, when you take the scope out to cool down should I put the dew shield on straight away or leave it off until an hour or so later when I actually use the scope ?
and is it best to have it pointed downwards during this time? ( the reason i ask that is because i read somewhere that this will help in getting rid of dew )
And from your experience have ever needed to use a dew heater in this region of the South East? ( i am in the Caloundra area )

Hi Ian,

I leave the corrector cover on during cool down, but that's mostly because I put it on a table in the backyard. When it's on the mount, I put the dew shield on straight away - I don't have the option of pointing down since the park position of my NEQ6 is pointing up at the SCP.

I don't have dew heaters. There was one occasion last year when, at a star party under very dewey conditions, I was "dewed out" - still, mine was the "last scope standing" so I lasted pretty well. I bought a 12V/10A hairdryer (it was only about $30) but haven't had to use it yet, although I think I came close last night.

100km away could have quite different seeing conditions, depending on the cause. If you're, say, close to an escarpment, then a breeze could rise sharply, cool and change direction causing additional turbulence. Also, heat islands, like a city centre, could affect seeing.

[ianB (Ian)]

Thanks Astro, conitions are not great tonight but i will have a try at Mars in the early morning 3:30 ish, I have never seen it and conditions may be better at that time early am, as long as there is no great cloud cover.

Ian

[ianB (Ian)]

It seems my scope needs to be collimated, I had a look at jupiter again this evening and once again the moons were not sharp and had a, for want of a better word, spike off to the left, and with jupiter it was clearer, more sharp on the right but fuzzy on the left.

So i tested the collimation on thee scope with a 6mm on a star and sure enough the black disc was off to one side.

So i had a go at doing the collimation........................ ............two hours later i gave up! :-)

Doing it in the dark is not easy and everytime i put a slight turn on the screw the star went out of the f.o.v

I will try and get a collimation kit as soon as i can and try it that way, from what i have seen it is easier to do it with this kit inside rather than try by myself in the dark with the star going out of view everytime i turn the screws.

Anyway when it gets done im sure my views of jupiter will improve.

ian

[ianB (Ian)]

P.S

Any suggestion on what one to get, there seem to be several types.

[Astro_Bot]

You don't need a collimation kit for an SCT. There's only one adjustment - the secondary - and all it takes is practice. At some point, it will "click".

When adjusting each screw work in small increments - one eighth of a turn is a lot!

A tip for young players is to use a stick, ruler, rod or even an empty/finished cardboard roll (for paper or foil). Hold it front of the scope so it covers centre to outside edge (with the diffraction rings showing) and you will see a shadow. This will help you orient the collimation screws to the pattern and help you pick which ones to adjust.

The first time I collimated, it took me a couple of hours - being very careful and learning as I went. Now I can do it in 5 minutes even using a real star. Having said that, I rarely need to adjust as SCTs hold collimation quite well.

[ianB (Ian)]

Yes, i will go outside and give that a go now.

[ianB (Ian)]

O.K so i had another go using the ruler as suggested, and yes it did make it easier for me and i think the collimation is good now, the moons of jupiter now looked like pin points without distortion ( as previously ) but as jupiter was now very low I could not get a real look at it, too much haze/cloud to look through as it was just after 1am.

Mars was very high and I took my first ever look at it with my 25mm and 9mm, conditions were i think reasonable, anyway it was interesting to see, i could just about make out some faint shadow but did not see any polar cap, but it was fun to see being my first time.

I might add my telescope had been inside for an hour or so and i took it out to do the collimation and took a quick look at mars while outside, so i doubt the scope had cooled down and I was on my balcony with the door open.

As Saturn was near Mars I thought i would have a peek, the last time I saw saturn through a scope was back in 1986, and then it was just with my 20 X 50 spotting scope.

With my 25mm at x 60 Saturn was beautiful to see, its been such a long time and i was not at all disappointed, even more beautiful than what i remembered.
I then put in the 9mm which gave me X 166, while the image was not as sharp as the 25mm it was still a lovely sight, especially considering the situation with the scope having just been taken outside about 20 minutes before.

Then the image in both the 9 and 25mm became foggy which I think may have been due to the humidity? ( i did not have the dew shield on as i was doing the collimation ) moments before the views were so much better, but i did not mind as it was getting late and i was making noise on the balcony and did not want to wake my my neighbours.

So while things started off badly they turned out much better.

ian


( looking forward to seeing saturn again, i even got my wife out to have a quick look, she loved seeing it )

[Astro_Bot]

Great to hear, Ian!

Regarding foggy: given the lenth of time you'd been out, more likely you breathed on the eyepiece, or that it was moisture from your eye caught within the rubber eyecup causing the same effect. Both of these things happen to me from time to time. If you shine a light on your corrector, you'll see if it's dew - it looks exactly like a misted up car windscreen.

[Camelopardalis (Dunk)]

Glad to hear you've jumped that hurdle, Ian

If you're craft oriented, a Duncan Mask, like illustrated on this chap's site might be worth a go ... http://alpha-lyrae.co.uk/2013/12/31/...a-duncan-mask/

As luck would have it, my scope appears to hold collimate on pretty well so I haven't had reason to tinker, but once I find a circular cutter I might

[ianB (Ian)]

Thanks for the link Dunk.

ian

[ianB (Ian)]

Things are looking up, no pun inteended.
As i need to be up early tomorrow i thought i would spend a couple hours on the balcony.
As suggested i had the balcony door closed all the time and 2 hours before going out, also cooled scope for 1 1/2 hours.
Again as suggested i checked SkippySky earlier today and conditions looked reasonable.

Anyway unlike the last few evenings the moon looked great in both my 9 and 6mm, lovely views and so much detail, im very happy as i really thought that at X 250 the moon would be a blurr, but not at all, great detail.

Jupiter was much better in my 9mm than previously, only had brief looks due to clouds all over the place, and it was less blurry and i saw a little more detail, ie the bands were not just straight bands but showed a little shape.

I just came in to have dinner but will be out soon for another hour, may even try mars if the clouds move on.

Ian

P.S
thanks all for your suggestions which have been of assistance.

[Camelopardalis (Dunk)]

Great! Sounds like you're on the right track Ian