Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

Getting started with a refractor telescope


Recommended Posts

Hi everyone, this is my first post here but I have been reading a lot of post before deciding to create an account and post my question. I just bought a Celestron AstroMaster 130EQ, and used it yesterday for the first time. However I am not sure if my experience was right or if I was doing something wrong. Here is a few notes of what I did/had:

1. I went to the mountains and was about 1800m above sea level, the sky seemed clear and I was able to see a lot of starts with my naked eye.

2. I only had the 20mm and 10mm eye pieces that comes with the telescope.

3. I aligned my laser finder beforehand and was pretty happy with the results as I was able to point and see any object I want.

4. I left the telescope out for around an hour to bring it to the outside temperature.

5. First I looked and the moon and brought it into focus and the image was very clear and sharp. I was able to easily see the craters with both eye pieces and with a lot of details.

 

Here is my issue, after watching the moon I decide to try something more challenging, so I pointed the telescope at Jupiter since it was also very close to the moon. I looked up a lot of images online and had my expectation tuned given the telescope and eye pieces, I knew it was going to be small. But my problem is that it just looked like a star, a shining white dot. I am sure it was Jupiter since I was able to see 3 of its satellites and they were at the same position that the Star Walk app showed me. Was I doing something wrong ? Can't I get better results with these equipment and at least see some kind of colors/details on Jupiter atmosphere ? I saw a similar post in here and the main advice was to collimate the score but I don't think this is the issue because I feel like the moon looked sharp enough. I was also able to find Saturn, the rings where barely visible, the separation between the planet and the ring is blurred.

 

If this is the best I can get with the current setup, then what do you suggest I change or add to get a better viewing experience.

Thank you in advance, and I hope to give back to this community when I get better 😛

 

 

 

Link to comment
Share on other sites

For planets you do need a lot of magnification. I had a look at Mars last night on a 250P-ds, thats 1200mm focal length plus I was using a 5mm eyepiece. It was still small and looked nasty because of atmospheric conditions. 

The higher the altitude of the target the less atmosphere you have to look through which helps. Also you need to have a look at your telescopes specifications to see what the maximum magnification can handle and then find a suitable eyepiece. If seeing conditions aren't good then nothing will really help you, but you can always pick another target like double stars.

Edited by MarkAR
Link to comment
Share on other sites

I think collimation is most likely the issue. The Moon is very forgiving from my experience and may look good even if the scope is not well collimated or cooled down. Maybe eyepiece itself is of poor quality, but it still should perform reasonably well in the center of the field of view and 65x should be enough to see some details.

Link to comment
Share on other sites

The Celestron AstroMaster 130EQ is given as a reflector, I assume you have the type wrong not the scope.

It is not one of the bird jones designs, very useful. For Jupiter you will need something around the 50x to 60x area to see banding. Should be easy with the scope. Saturn is different. 40x to 50x should show the ring however for the cassini division it seems that 120x and above is required and besides just magnification the image needs to be good. Reflectors can give a softer image. Thereby masking the cassini division.

Scope is 650mm focal length so 50x means a 13mm eyepiece. Unaware of a specific 13mm but there are numerous 12mm eyepieces around. The BST range seems popular, also there is the X-Cel LX range.

For the higher then you will need something like a 6mm eyepiece, 108x and that may just be on the low side. Again unaware of a 5.5mm, there are numerous 5mm.

The eyepieces you have are likely fairly poor, also at f/5 it seems that you are on the boarder lline for being able to use what is best described as inexpensive eyepieces.

The 20mm eyepiece will probably deliver too small an image, 32x. and in the case of Jupiter that will be a small bright image and so likely the detail will be lost in the brightness.

I would suggest that you need a couple more eyepieces, or a zoom if preferred. Also they need to be reasonable eyepieces. Cannot really help a great deal on that aspect, and as with all cost is a factor. At this stage I would say leave thoughts of collimation out.  Sort out one aspect at a time.

Link to comment
Share on other sites

9 hours ago, anthonyyaghi said:

Would it be better to get a like a 4mm or 6mm eye piece or an x2 barlow ?

One advantage of a 2x barlow is that it can be used with any eyepiece, so it's got multiple uses. Get a 30mm eyepiece for wide angle views, and  the barlow means you have the use of a 15mm for free.  

Another is that using the barlow means you (mostly) keep the benefits of the eyepiece - and given that a 10mm eyepiece is likely to have a bigger eye lens and better eye relief than a cheap 5mm, it can make it easier to use. 

  • Like 1
Link to comment
Share on other sites

Using a field of view calculator is handy in this situation. Putting your scope details in along with a 10mm eyepiece shows the field of view and size of Jupiter you will get with your scope. This is shown in the attached picture.

As you can see Jupiter will appear quite small with your scope and a 10mm eyepiece. 

Screenshot_20200927-083257_Chrome.jpg

Link to comment
Share on other sites

On 26/09/2020 at 14:06, anthonyyaghi said:

If this is the best I can get with the current setup, then what do you suggest I change or add to get a better viewing experience.

Hi,

I have the same scope and the two eyepieces that come with it are not that great. I purchased a Barlow (the Baader 2.25x https://www.firstlightoptics.com/barlow-eyepieces/baader-classic-q-225x-barlow.html) ) and a couple of eyepieces and that improved my viewing. A quick method to slightly improve the quality is remove the erecting prism in your 20mm eyepiece. 🙂

But even with the 10mm one that came with the scope you should be able to see the banding on Jupiter (albeit quite faint). I can see this from my garden in Bortle 6 skies with street lamps etc. If your collimation is off, the image may not be crisp but you should still be able to see the hazy details. Sometimes you have to keep staring at it for quite long before the details leap out, so have patience.

Do the stars show up as dots rather than blobs? If so thats a good start and you can enjoy seeing DSOs while you sort out the eyepieces for observing planets. Suggest looking at the Double cluster in Perseus, Andromeda galaxy and the Globular cluster in Hercules to start with.

Good luck

  • Like 1
Link to comment
Share on other sites

On 28/09/2020 at 12:51, AstroMuni said:

Hi,

I have the same scope and the two eyepieces that come with it are not that great. I purchased a Barlow (the Baader 2.25x https://www.firstlightoptics.com/barlow-eyepieces/baader-classic-q-225x-barlow.html) ) and a couple of eyepieces and that improved my viewing. A quick method to slightly improve the quality is remove the erecting prism in your 20mm eyepiece. 🙂

But even with the 10mm one that came with the scope you should be able to see the banding on Jupiter (albeit quite faint). I can see this from my garden in Bortle 6 skies with street lamps etc. If your collimation is off, the image may not be crisp but you should still be able to see the hazy details. Sometimes you have to keep staring at it for quite long before the details leap out, so have patience.

Do the stars show up as dots rather than blobs? If so thats a good start and you can enjoy seeing DSOs while you sort out the eyepieces for observing planets. Suggest looking at the Double cluster in Perseus, Andromeda galaxy and the Globular cluster in Hercules to start with.

Good luck

I got a 6mm eye piece and an x2 Barlow. I will try to check the DSO you mentioned. Thank you :)

Link to comment
Share on other sites

If your scope is goto, then use the scope furnisher application, with it, calibrate with knowing stars & use a planetarium (skysafari, stellarium, ...) to help you go your choose targets.

At the beginning, it is not easy. When you buy a scope, only the great focal eyepiece (20 to 25mm) is useful (but with low magnification). The low focal eyepiece is always awful.

For eyepiece, following my experiences:

- first: celestron xcel-lx series,

- second level: explore scientific (82° for low focal & 68° for higher focal)

They are available everywhere (astronomy shop, amazon, ali,...). You could also replace the planetarium by a map book (I have one, I never use it, too many details for beginner).

I prefer Android application with a tablet, it is simple & you could travel with your fingers (it is intuitive).

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.