New to...well everything about Astronomy

[Ydoow]

I've been dying for a year to get a telescope and start gazing, and finally this wednesday I received an Orion AstroView (90mm)

I went out Friday and saw Jupiter, Saturn and the Moon with what came in the box, 25/10 mm lens. Incredibly clear/crisp, but I sat and wondered how I could improve and what to do next.

Here are a few things I noted:

1) I couldn't get myself Polar Aligned properly. I aimed my mount for the North star, but noted it was pretty far off from Magnetic north. From my viewing it felt like I was far from polar aligned; I had to adjust both RA and DC to keep objects centered each time it left the viewing field. Any tips/suggestions? My bubble showed everything was level.

2) The pictures we're great, but small! I was almost a little let down by that. I guess after watching movies like Space Odyssey I was expecting to be able to see Jupiter like I could the Moon. So what would be the best way to get a larger image (higher zoom) with minimal picture degradation? Barlow, new eyepiece, something else?...

3) I'm trying to find the maximum magnification my telescope can support before I start buying add-ons for it. No sense in buying something I can't utilize. However I can't find any concrete equations to use for this, just a general "30-50x your aperture in inches."

That's a start, but I guess I really want to push my scope for all it can give me.

With the stock parts, this is what I have available to me

910mm Focal Length

90mm Aperature

25 mm Eyepiece

10mm Eyepiece

910 / 25 = 36.4X

910 / 10 = 91.0X

How much more can I squeak out of this? I'm already looking at adding a Barlow to my set, but being on a college budget, I can't just spend money all will-nilly. Purchases need to be wise ones.

4) Sliding the eyepiece out/in (adjusting the focus, and I guess therefore the focal length(?)) involves me directly touching the scope and sending jitters throughout. Is there any way to minimize this or work around it entirely? I attached an image with arrows for clarity, and properly cropped for your bandwidth viewing pleasure

The knob with the arrow traveling in a circle is the one I must rotate to adjust the focus, and causes things to shake.

Thanks for your time reading and helping me out, to those who do. I hope to have a long life of stargazing ahead of me

[Carl Reade]

Hi a 90mm refractor is a very capable scope. Yes planets are small most use high magnifications for planets and lower for DSOs and nebs. A 2X barlow will help with planets and bring out more detail. On the focus bit they all wobble you just need to be patient and let it settle when adjusting, all quite normal. When going for a planet I would use the 10mm and a Barlow. You probably have seen pics of Jupiter etc with webcams they are equivalent to a 7mm eyepiece and are often Barlowed as well so you can imagine the focus wobble at those magnifications lol.

Polar aligning is practice.

Hope this helps Carl

[ronin]

Nice scope to get going with, and really a nice scope to keep, it should do just about everything you need.

Forget magnetic north, nice if magnetic and polar alignment were the same but as they are not ignore magnetic, you want polar alignment.

Generally for visual reasonable polar alignment is adaquate.

To stop (reduce) the shakes really means a more solid mount, that in turn means more cost.

Without motors everything will drift out of view, another reason for a better mount.

More magnification, I would go for a couple more eyepieces, the scope if f/10 so an 8mm even a 7mm should be OK and a 30mm or 32mm for wider views. This assumes that the 2 you have are good which you say they are. You should be able to get to 120x, a little more may be possible. What you could find is the 7mm will not work too well but an 8mm does.

Where are you in the UK - I assume UK.

Moving the eyepiece in and out just moves the eyepiece, the scope focal length is fixed by the front objective. You adjust the position of the eyepiece to get the focal plane of the objective (fixed) to conicide with the object plane of the eyepiece. Then what you see should be in focus and magnified.

[jaygpoo]

Hi , I top am new to the world of astronomy and this site has beed very helpful. I started with a plastic scope costing £10 and got the bug. I then brought a 150 reflector on a wobbly mount. You soon find out that the mount is more important than the scope and a good mount will mean better alignment and much less shake. I big long scope on a small mount will be trouble from the start. I then brought a 127 skywatcher cassigrain scope. This is small light and for its size the most powerful scope I have as its focal length is 1500mm . Thease are great for planet viewing and easy to crank up with a barlow. I sadly got into imaging and now have a ED 80mm APO . The Mount I have at present is a EQ5 that I have motorised so that I can enjoy looking without the drift. A barlow x2 would greatly help you get good close ups of the moon and saturn . Polar alignment is something that took me forever to get right . There are many internet sites that will help you to understand how to do it and Youtube has lots of clips on the subject + many more on all aspects of astronomy . These have helped me over the last 12 months. Keep you hand firmly on ypur money as believe me the world of astronomy is always sapping money in some shape or form as I have found to my cost so far. ENJOY Jay

[Ydoow]

Wow thanks for the advice! I'm glad this is a good scope I purchased. I had been planning for weeks on going with a different one, then last minute I found this, and despite it being $100 more, it had great reviews and I decided it may be worth it in the long run.

I am located in NY, USA. I believe that's a rather similar latitude to the UK, ronin.

Can you explain what f/10 means?

[ronin]

The f number is the focal length of the scope divided by the diameter of the objective - lens or mirror.

Yours being 910mm focal length and 90mm dia give a value of 10, so it is f/10.

The value tends to give characteristics to a scope.

In general the folowing:

Being an achromat an f/10 scope will be better for CA (Chromatic Aberration) then an F/5 achromat.

At f/10 you will generally not need so expensive eyepieces, a decent plossl will give good results. Something like an Astro Tech Paradigm should be very good.

Your scope would be described as "slow" at f/10, an f/5 scope would be described as "fast".

Fast and Slow being photographic terms and there relevance is for the imaging aspect.

At f/10 and with a focal length of 910mm your scope is not really suited to imaging. - additionally you would need a sturdier mount and motor drives for that.

There are one or two others in NY on this site, Umadog is one if I recall from posts made. Think another appeared about a week or two back.