Looking to get my first telescope for christmas

[racshot65]

Hi,

I'm looking to get my first telescope for christmas and need some advise on which one would be most suitable.

I want to look at planets like Jupiter and its moons and our earths moon mainly. But also some star clusters.

I have about £150 to spend.

What would you recommend ?

Also as this is my first telescope what else will I need to be able to go out and use it?

I've been browsing the forums and seen words like 'eye pieces' mentioned, do these come with telescopes or do I have to buy them separately?

Thanks

[ronin]

I am tempted to suggest a Skywatcher Evostar 90 on the EQ2 (?) mount from FLO.

It comes with a mount, diagonal and an eyepiece or two. The eyepieces are never great a a rule but are something to start with.

The scope is an achro refractor but being reasonably long the CA will be minimal. It will also be good for the magnifications wanted for viewing planets. Cost is £149, can get it an an Alt/Az mount for £139. Neither mount is very solid.

There are reflectors that come in for the same cost and with larger apertures, However you would need a collimator as well to maintain colimation say £25-30. So if £150 were the max then a collimator has to be taken into account.

If a reflector then you need a parabolic and these tend to be around f/5, Being possibly a shorter focal length then magnification is a bit more difficult.

[Nosivad]

Hi and welcome. I would suggest you look at first light optics. Their logo is at the top of the page to see what your budget could afford. Basically the bigger the diameter the better as far as light gathering power is concerned. By the way 6" or 6 inches is about 150mm , 10" is about 250mm etc. A telescopes focal length also dictates what magnification you will get with a certain eyepiece. With your original list of objects then an eyepiece of about one fiftieth of your focal length would be good. Have a good look round before you commit to buying and don't hesitate to ask again if you are unsure. Good luck!

[nightfisher]

i would second the suggestion of the evostar 90mm

[racshot65]

I am tempted to suggest a Skywatcher Evostar 90 on the EQ2 (?) mount from FLO.

It comes with a mount, diagonal and an eyepiece or two. The eyepieces are never great a a rule but are something to start with.

The scope is an achro refractor but being reasonably long the CA will be minimal. It will also be good for the magnifications wanted for viewing planets. Cost is £149, can get it an an Alt/Az mount for £139. Neither mount is very solid.

There are reflectors that come in for the same cost and with larger apertures, However you would need a collimator as well to maintain colimation say £25-30. So if £150 were the max then a collimator has to be taken into account.

If a reflector then you need a parabolic and these tend to be around f/5, Being possibly a shorter focal length then magnification is a bit more difficult.

Hi,

Thanks for taking the time to reply

I'm looking at the Sky Watcher on FLO's website now

What is a 1.25"/31.7mm Star Diagonal ?

Also what does " .. the CA will be minimal. " mean, is this a good thing ?

How big a problem will the mount not being very solid be ?

Finally, what sort of views can I expect from the scope ? Will I be able to see Jupiters bands and moons clearly?

Thank You

[malc-c]

If you can stretch you budget to £197, the 6" Skywatcher dob would be an ideal starting scope Skyliner 150P 6" Parabolic Dobsonian | Telescopes | Rother Valley Optics

[Nosivad]

Hi,

Thanks for taking the time to reply

I'm looking at the Sky Watcher on FLO's website now

What is a 1.25"/31.7mm Star Diagonal ?

Also what does " .. the CA will be minimal. " mean, is this a good thing ?

How big a problem will the mount not being very solid be ?

Finally, what sort of views can I expect from the scope ? Will I be able to see Jupiters bands and moons clearly?

Thank You

Hi again, CA is chromatic Aberration and is a measurement of how much the lens, ie glass piece of a refractor( that's the one with a lens at the top) bends the light. It creates a rainbow effect around objects( not that obvious so don't be put off) because light of different colours is bent differently by the lens.

A sky diagonal is basically a clever piece of mirrors built into a unit which allows you to observe without having to be in line with the telescope.

I have a 6 SE ie a 6inch telescope and with good eyepieces I see the bands on Jupiter, when a moon crosses in front, and our own moon is awesome!!

Enjoy!

[umadog]

>What is a 1.25"/31.7mm Star Diagonal ?

It's a mirror set at 45 degrees into which you can place a 1.25" eyepiece. With a refractor, such a 45 degree mirror is pretty much obligatory. Viewing angle are quit unpleasant without.

>Also what does " .. the CA will be minimal. " mean, is this a good thing ?

CA is chromatic aberration. Best to Google that and you'll understand what it means. The less chromatic abberation the better. There's no reason you should have known a jargon abbreviation like that.

>How big a problem will the mount not being very solid be ?

It depends how "not solid" it is. A wobbly mount is pretty annoying. As is a mount that makes it hard to point a telescope.

A 6" Dobsonian is certainly worthy of consideration. You have to ensure that the mirrors are aligned in a reflector. The accuracy with which you have to do this depends upon the focal ratio (Google it). Telescopes with smaller (shorter) focal ratios need to be aligned more accurately. Basically, f/5 and shorter need to be aligned pretty accurately. The 6" mentioned above is an "f/8" telescope and will be tollerent of misalignment. It's will probably come with a little plastic tool referred to as a "collimation cap." Basically, it's a little plastic disk with a hole in the middle. Usually these things have have silvered inside surface which, for reasons that become clear when you use it, allow you to use the tool to adjust the primary mirror. With a focal ratio of f/8, this tool is going to be sufficient for you to enjoy the telescope. You won't need to fork out extra cash. Should you choose to fork out extra, you would buy something known as a Cheshire/sight-tube combination tool. This gives you a more accurate way of adjusting the secondary mirror (the sight-tube), but it's probably not super-necessary at f/8. The combination tool also comprises of a component known as a "Cheshire" which achieves the same thing as the "collimation cap" you would already have and does so in the same way.

[racshot65]

Hi,

Thank you all for your replies I like the sound of the Skywatcher Evostar 90.

If I was to spend a bit more and get the £197, 6" Skywatcher dob would I be able to notice the difference as a beginner ?

What could I see with that, which I wont be able to with the Skywatcher Evostar 90 ?

Thank You

[John]

Th e 6" scope will show deep sky objects more clearly than the 90mm refractor and will show more detail on the moon and planets. For example, the 90mm will make seeing Jupiters Great Red Spot really challenging wheras it will stand out more clearly with the 6" dobsonian (if the seeing conditions are good). The 6" scope collects nearly 4x as much light as the 90mm one - that's going to make a big difference on practically everything you observe.

Nothing wrong with the 90mm refractor of course it's just that more aperture is really worth having.

[umadog]

Definitely you will notice a difference as a beginner. However, it's not nearly 4 times as much light: it's more like 2.8 times (150^2/90^2). That's not taking the secondary mirror obstruction into account, although the influence of that is negligible. Both from the perspective of light loss and the perspective of contrast loss.

[racshot65]

Hi,

I found this video on Youtube

It says its from a Sky Watcher DOB 6"

Is the quality of the recording poor or is that what I can expect to see ?

Jupiter appears to be an orange blob with no sign of its bands.

Regardless of which telescope are there any accessory's I really need to get ?

Thanks

[umadog]

That's a pretty useless video, to be honest. You will see much more with the naked eye. You can hardly see the moons in that video, and those are binocular objects. Generally speaking, photographs and videos aren't a good guide for what you'll see in the eyepiece. They usually either underestimate or overestimate what you'll see by eye. This is the sort of thing you should expect: http://www.universetoday.com/wp-content/uploads/2008/10/jupitermoons20050513composite.gif On a good steady night (so-called nights of good "seeing") you may see more details on the planet's disk.

The scope comes with eyepieces. The only thing you might want to consider is some sort of reflex sight for locating objects. e.g. a Telrad, a Rigel Quickfinder, or some other red-dot sight. These are like a pilot's head-up-display and project a red dot or circle(s) onto the sky. They are much, much, easier to use than the finderscopes (the mini-telescope thing) which come with most scopes. Finding objects will be your first concern and these reflex sights will make your job easier.

[racshot65]

Hi,

I'm tempted by the Skyliner 150P 6" Parabolic Dobsonian now.

Skyliner 150P 6" Parabolic Dobsonian | Telescopes | Rother Valley Optics

Is it just me or does it look really short in that picture ?

Do you have to kneel down to use it?

[umadog]

Use a garden chair.

[John]

... However, it's not nearly 4 times as much light: it's more like 2.8 times (150^2/90^2)....

Fair point - that will teach me to rush my posting

[Nosivad]

That telescope is 1.2 metres focal length, so basically the tube is near enough that length. That plus the mounting height will bring it to a position that when pointing straight up, you will have to lean a bit when observing and when low towards the horizon you could use a garden chair. Sorry but it's one of the things that amateur astronomers have to put up with. A larger dobsonian would have a longer tube and so less bending when observing straight above.

[GarethA]

I have the 150p and you can certainly see the moons of Jupiter and the cloud bands. The Great Red Spot is visible but it needs to be a good night and you need to time it right.

Saturn also looks great through this scope with the rings clearly visible.

If you buy the skywatcher through FLO you'll also get all the eyepieces etc you need to get going.

I bought this scope as my first earlier this year and have been really impressed with it.

Good luck...

[malc-c]

Regardless of where you buy from, all the scopes in this range came with a set of eyepieces and a barlow lens. It's no good looking at video's on the web as most camera's don't have the field of view the eyepieces, nor the sensitivity.

The problem you are going to have is your budget. £150 means you are going to have to compromise, either on mount stability or observing posture. There is no such thing as a general all-rounder scope. Refractors have their good and bad points, as do reflectors. The mounts used on dobsonian have the plus points and negative points, as do German equatorial mounts. The other problem is that below £400 there are lots of scopes to choose from, so there is always going to be that temptation to say "for another £40 you could then have..." and then repeat that process because that then puts you within £50 of the next scope with more features or larger aperture.

You also have to respect that for your budget you are going to get the most basic of mounts. It's the mount that makes the difference in having a pleasing observing session rather than a frustrated one. If the mount can't hold the scope steady then even with good optics you'll soon get disillusioned with the hobby. In my opinion for your budget you won't get a better mount than a dobsonian (never thought I would hear myself saying that ).

Yes reflectors need to have their mirrors colimated now and again, but there are a wide range of tools for doing that and it's something that you can add later.

The other suggestion would be to save up and increase your budget, although that would mean missing Christmas (I assume it for a present for someone)

[Pauly]

You could look for a local astronomy group and ask nicely if you could have a peek through some of their kit. At least you'll know what to expect. Also consider second hand, but I would strongly recommend doing the deal face to face, and enlisting the services of someone who can advise you on the quality of kit you are considering and whether it is in good order, i.e. undamaged and no bits missing. Again, a local astro group might be willing and able to help with that. All my kit is second hand and has come to me in as new condition. Fortunately for us proper astronomers look after their kit.