10" Bintel DOB Purchased - Finderscope Question

[chich0 (Chris)]

Well!!!

I went out today and got the 10" DOB from Bintel.

I also got an Orion Cheshire and the 3 volumes of Night Sky Observers guide as recommended to me by forum members

These scopes look a lot smaller in pictures lol!

I tried aligning the finder scope with the telescope.

How accurate can you get this? - I get it within a few MM when looking through the finder scope, but it sways a little when adjusting. Can it be perfect? If so how?

I also got a Telrad but forgot to buy batteries, have mounted it but will need to align it once my finder scope gets figured out.

[Marcus10 (Marcus)]

Hi there,

The easiest way to align this is to use a fairly high power eyepiece, or even one with a cross hair, and perform an iterative process whereby you centre in the finder, centre in the scope and keep doing this until you are spot on.

Bear in mind that the finder position is easy to knock accidentally - then you will need to start again. I generally adjust the alignment every observing session.

[chich0 (Chris)]

Coool

I will give it another go tomorrow when i can see!

Overcast for the next few days here, cant wait to give it a go!

[barx1963 (Malcolm)]

Chris
I always do an initial alignement in daylight of course being careful to NEVER point scope anywhere near the sun!.
Pick a reasonably distant object, a branch on a tree, TV aerial, I use a chimney poit on a house a couple of blocks away.
Find it in your scope with your lowest power EP then adjust the finder so it has the cross hairs on the target.
This will get it close enough so at night pick a bright star, line up with the finder on it, then centre it in the FOV of the main scope, then adjust the finder. Once you have done this a couple of time, it conly takes a few seconds.

Malcolm

[chich0 (Chris)]

Cool thanks!

I am going to do a star test to test the collimation when i have some clear skye, if the star is wonky as i have seen in some digrams, which do i adjust the primary or secondary mirror if it is as close as i can get it with a cheshire?

[Waxing_Gibbous (Peter)]

With a dob, I would ditch the optical finder and use either a Telerad or Red Dot finder.
I find them much easier to align and less prone to getting knocked.
Just a thought.

[chich0 (Chris)]

I got the Telrad but i haven't bought batteries for it yet!

I will align it as soon as i get some, I Managed to align the finderscope pretty good, i have a few trees i can see about 2km or so away.

Decided to play with it so i knocked the collimation out while finding my way around what things do. I re-collimated it pretty good i think but boy it took me a while lol.

Hopefully i get faster at it so i don't look like too much of an idiot when i go to a dark sky site and some of you guys see me!!!!

On my previous question about the star test, is it the primary or secondary that i have to adjust if it is out? or can it be either one?

[Waxing_Gibbous (Peter)]

The secondary would be the go. You'd want to leave the primary alone as much as possible - largely as its more of pain to get right on a big scope.
However it may not be enough just to adjust the secondary, in which case, I would "zero" both out (get them as close as possible to their original positions), lock the primary and start from there.
Also, I found that doing the collimation while the scope was at, say, a 45-60 degree angle made a difference.
I assume the weight of the primary, combined with the rather weak springs, helps to drag itself out of collimation when moving through its arc.
This is just what worked for me.
I'm a long way from being an expert at collimating newts, so anybody with more cogent advice, please sing out!

[chich0 (Chris)]

Well after a very gloomy day at work i have come home to some sunshine!!!

I might be able to use it this evening, fingers crossed all goes well!

[chich0 (Chris)]

WOW!

My collimation was really good! It's nearly a full moon so a very bright night.

Saturn looked very cool!!!! The moon wasn't too bad didn't spend much time observing it though as i wanted to try my hand at some DSO's

Well for my first time i think i did OK.

I managed to located and get a decent view of about 8 DSO's

Or not so DSO's?

M4, M6, M7, NGC6025, NGC3532, NGC3293, NGC3114, NGC4755 and I think i saw the carina nebula?? I couldnt see any dust really, more star formations similiar to when i look it up in stellarium is that how it is meant to look when observing??

For a bright night and my first night out i am pretty stoked with that. Got to see a lot more then i thought i would to be honest

[Gem (Grant)]

Originally Posted by chich0

and I think i saw the carina nebula?? I couldnt see any dust really, more star formations similiar to when i look it up in stellarium is that how it is meant to look when observing??

For a bright night and my first night out i am pretty stoked with that. Got to see a lot more then i thought i would to be honest

With your 10" you should be able to see the dust lane easily, however between the full moon and it being a first night out - don't worry if you didn't! Your eyes will get used to knowing what to see the more you observe. I usually see something clearly, then when I ask someone newer to astronomy to look in the eyepiece: they see nothing!

Keep it up! The moon makes a big difference for DSO. If you are in town, I would suggest trying globular clusters more than nebulae or galaxies. I have used the free "Astrobyte" software to print out a list (used print screen - it is easier than the print format) of the brightest globular clusters. There are 60 globulars that are mag 8.9 or brighter. All bar two or three should be visible from Melbourne.

Anyway, have fun!!