My view looked like this

[ianB (Ian)]

As you may know I have talked about collimation recently and this is related to it.

This photo is very close to the view I got from my telescope ( 6 SE ) the other night in between the clouds, conditions were reasonable but not great.

If my telescope was a little out of collimation would I get an image this this, or is this the type of image expected for a scope with good collimation ?

I saw an image like this, maybe a touch better with my 25mm X 60
with the 9mm the image was like this but just larger. X166

ian

[barx1963 (Malcolm)]

Ian
I am certainly no expert on collimating SCT's but I would assume that similar principals apply to them as apply to Newtonians. Firstly collimation becomes "harder" as the focal ratio decreases. This means that you have to be more finicky and careful collimating an f4 scope than an f6 one. A 6SE is f10 I understand, so it will be quite tolerant of slightly off collimation. Secondly, the exact purpose of collimation is often misunderstood. It's purpose primarily is to ensure that the zone of maximum illumination of the image is centred in the focuser so that as much light as possible is being used by the eyepiece or camera. So being unable to get really good focus is almost certainly not a result of any collimation issues.
The poor image you are seeing is far more likely to be the result of poor seeing conditions, and given Jupiter (which is having a very poor apparition ATM for we unfortunate Antipodeans!) is the target, that is extremely likely.

Cheers

Malcolm

[ianB (Ian)]

Thanks for explaining that about the purpose of collimation and its relation to illumination, I have read numerous articles in recent days and that was never mentioned, but I understand what you are saying.

[ianB (Ian)]

Just thought i might add Saturn looked lovely in the 25mm, much sharper than Jupiter.

[astroron (Ron)]

Ian, I agree with Malcolm, I believe your problem is seeing and not collimation.
The seeing of late here at Cambroon has been dreadfull and I would say looking at your image that is your problem as well.
Saturn may look sharper as it is smaller and so will have a sharper contrast,but if you looked it at high mag you would see it is just as soft as Jupiter.
Observing in caloundra not far from the sea and heat from the buildings etc would definitely not help in any way what so ever.
Cheers

[ianB (Ian)]

Thanks Ron, and now its raining heavily here, I look forward to the F1 season, at least then I can stay in and watch the late night racing when its bad outside.

[barx1963 (Malcolm)]

Ian
Here is a link to Gary Seronik's article on collimation with a newtonian. The process described is pretty straightforward, but the interesting bit is the explanation of why collimation is necessary at the end.

http://www.garyseronik.com/?q=node/169

Malcolm

[OzStarGazer]

I am no expert, being a newbie myself, but I think what others have said is correct - namely that it is rather a problem of seeing conditions. With the 25mm eyepiece the image should usually be very sharp, and you say it was not much better... The image seems to be out of focus rather than distorted.

[Quoll (Bill)]

Ian, I agree with what has been said about seeing conditions.

I’m a newbie but what I’ve learnt so far is that seeing conditions make a HUGE difference. You say “in between the clouds, conditions were reasonable but not great”. That says it all.

Last week I got up in the wee hours to view Saturn when it was high in the sky to get better views. To my inexperienced eye the seeing was “great” as I saw several of Saturn’s moons.

Last night I was observing Saturn around midnight when it was a lot lower in the sky. Well what a difference good seeing makes! To my inexperienced eye I would describe last nights seeing as “excellent”. Even though it was low in the sky I was able to spot what I’m sure were even more of Saturn’s moons than I’d seen previously (still to confirm).

It’s only after experiencing a variety of seeing conditions over a period of time that we can really appreciate the difference in viewing conditions.

The other thing I’ve learnt is that having a range of EPs would help as you could GRADUALLY increase the magnification till you found the optimum. I currently have a limited range of EPs so tend to Barlow which results in big jumps in magnification often with poor results. I notice you jumped from 60X to 166X.

BTW the other thing I’ve discovered as a newbie to astronomy is that it can be a hazard to my health - if lack of sleep doesn’t kill me, caffeine will

[Pinwheel (Doug)]

What's interesting here is, as I have new 12" toy I've discovered "Atmospheric Turbulence" in a big way & have had great pleasure watching the ripples & swirls around the furthest edge of the Moon as the Sun sets. It's funny in a sort of weird way.. The air seems to move like a fluid or water, IMO.

[ianB (Ian)]

Thanks Bill, I think im just too impatient and wanted to get the scope out, even if conditions were not good, i guess in time when the conditions get better i will get better results.
We have had non stop cloud cover for about two months now, thats when i got my telescope, and as i type its raining yet again.

As i have not been able to get out with it i have been doing so much astronomy related reading concerning telescopes and ep's.

There are three things that i have learned concerning this hobby:
1. You need to be very patient
2. It can be an expensive hobby
3. There is so so much more to astronomy that just taking out a telescope pointing up at the sky and looking into it.
( but i love learning and i will )

ian.

[ianB (Ian)]

Yes Doug, from my brief observations there is a lot to see when the moon gets low to the horizon, must be great with a 12 inch scope.

[Camelopardalis (Dunk)]

Originally Posted by ianB

There are three things that i have learned concerning this hobby:
1. You need to be very patient
2. It can be an expensive hobby
3. There is so so much more to astronomy that just taking out a telescope pointing up at the sky and looking into it.
( but i love learning and i will )

But the beauty of the hobby is that all you need is a little interest, and you can get into it practically with just a pair of eyes, or binoculars, or as little or as much telescope as you wish and still experience the wonder...there's something up there for every budget