Planetary views - telescope troubleshooting

[borginz]

Dear forum,

I'm a new telescope user, still trying to get my telescope to work properly.
I have recently tried to look at Jupiter and Saturn from my own telescope and then compared with a friend's telescope. The friend's scope shows a much better picture, and maybe you can help me to figure out what I'm missing.

My telescope:
Celestron Starsense Explorer LT 127AZ
D = 127, F = 1000 f/7.9
Eyepieces: 25mm, 10mm, Barlow 2x

Friend's telescope:
Meade Infinity 90
D = 90, F = 600 f/6.7
Eyepieces: 26mm, 6.3mm

Viewing Jupiter, my friend's Meade with the 6.3 eyepiece showed a much better picture: focused, clear such that stripes are visible, in colours that seems true.
My telescope, on the other hand, shows Jupiter as a white circle (no stripes), smaller and harder to focus on.

Is it possible I'm not using the right eyepiece?
I know that the calculation of the optimal eyepiece is: F/(2*D), which in my case yields 1000/(2*127)=4mm. If I use the Barlow 2x with the 10mm eyepiece, I get the equivalent of 5mm, as I understand it. Should I expect a big difference between this 10mm+Barlow2x and an actual 4mm eyepiece (without Barlow)?

Also worth mentioning that I used my Celestron at 55⁰ latitude, and my friend's Meade at 32⁰. Can that make a big difference? Hard to believe that a ø127 telescope cannot get a proper view of Jupiter from the north as well...

If anyone has any ideas, I'll be happy to try them. Thank you in advance!

[John Baars]

There are four main reasons why your telescope performs significantly less on Jupiter.

The first is the presence of a focal lengthening lens in the focusser. If this is not perfectly collimated or not of perfect quality, the telescope will give poorer images. Don't try to collimate this lens yourself, it just won't work.

The second is that your telescope has a 41mm central obstruction ( the secondary mirror) in the light path. Any obstruction in the light path reduces contrast transfer. It is an optical law.

Third, the image is formed by an F4 factory mirror, which if not made with the utmost care, are not known for their precision. Mirrors reflect light and double an optical error with each reflection. There are two mirrors in your telescope. Any small error is therefore quickly depicted a lot larger. Even factory lenses, like the one in your friend's telescope, are a lot more forgiving in that area.

Fourth, a mirror telescope must acclimate much longer than a lens telescope. If you don't pay attention to that, you will continue to be annoyed by a degraded image for the first 30 minutes.

It seems that the manufacturer of these types of telescopes go out of their way to market their product as economically as possible. While it is precisely this type of telescope that requires the highest possible precision.
Perhaps you would have liked to hear something else, such as a defective eyepiece, but I cannot make it better.

In spite of that, your telescope will perform on deepsky objects. Jupiter, after all, is a pretty stern test.

Latitude does make a difference. At lower latitudes, Jupiter is now higher in the sky. That makes quite a difference in seeing.

So what can you do?
Make sure your telescope is fully at outside temperature before comparing.
Only compare images of Jupiter that are at the same altitude. Any difference in that does make a difference.
A comparison on deepsky object may have a different outcome!

[Baurice]

I endorse what John said. I consider the difference in latitude is very significant.

The other thing to consider is that planetary seeing varies so much, from one night to the next and even from one hour to another. This happens even when there is no apparent difference in weather conditions. This is especially noticeable with Mars.

[turboscrew]

You might want to check your seeing here:
https://www.meteoblue.com/en/weather/ou ... rk_2618425

Don't expect a good view if the seeing is bad, even if the sky looks good to naked eyes.

[Bigzmey]

Welcome to the forum Borginz!

I wish I had a good news for you, but your scope is a Bird-Jones design reflector which makes it very bad beginner scope. For this type of scope to perform well it needs to be manufactured with good quality parts and precision which is not achievable at price point of a beginner scope.

I would suggest to return or sell your scope if possible (even at loss) and get a small refractor (80mm or larger) instead, like your friend.

[turboscrew]

If you are handy and have the time...
https://www.cloudynights.com/topic/6497 ... ker-127eq/

Just concentrate on selected parts.

[GCoyote]

You might want to check your seeing here:
https://www.meteoblue.com/en/weather/ou ... rk_2618425

Don't expect a good view if the seeing is bad, even if the sky looks good to naked eyes.

Cannot emphasize this enough. Transparency and jet stream turbulence can easily smear out any details like cloud bands, rings, and polar caps.

I don't decide what targets to try for until I see the detailed seeing forecast a few hours before my session.

[mikemarotta]

I'm a new telescope user, still trying to get my telescope to work properly.
I have recently tried to look at Jupiter and Saturn from my own telescope and then compared with a friend's telescope.

First of all, you are comparing apples and oranges. Not only are you comparing different instruments, but in different places. Latitude is one thing, but the "seeing" of the sky is more important. Other lights, sea and ground effects, and the general weather are usually more important than the aperture and eyepieces and reflector versus refractor. No two nights are the same. No two places are alike.

I wish I had a good news for you, but your scope is a Bird-Jones design reflector which makes it very bad beginner scope. ... I would suggest to return or sell your scope if possible (even at loss) and get ...

Bigzmey gives good advice but this time I have to disagree. Whatever the limitations of one design over another, the best telescope is the one that gets used.

You have viewed Jupiter, Boris. Have you seen Saturn? Have you picked out its moon Titan as different from a star? Have you tried to view binaries such as Albireo? Have you tried to split the double-double in Lyra? There's a lot to see with any telescope. What books or websites are you using to plan your observing sessions? How do you keep your notebook (paper, cellphone, computer)?

[notFritzArgelander]

Welcome to the forum Borginz!

I wish I had a good news for you, but your scope is a Bird-Jones design reflector which makes it very bad beginner scope. For this type of scope to perform well it needs to be manufactured with good quality parts and precision which is not achievable at price point of a beginner scope.

I would suggest to return or sell your scope if possible (even at loss) and get a small refractor (80mm or larger) instead, like your friend.

It's possible to make a good Bird-Jones scope but no one does. Unlike a refractor, which can be twiddled with to optimize performance, a Bird-Jones is not something that can be fixed. Either you get really lucky, defy the odds and get on that's good to go, or more likely, you get something that sucks the joy out of astronomy for you. I wish mfrs would quit trying to make Bird-Jones for cheap. It's a highly improbable task.

[Bigzmey]

It's possible to make a good Bird-Jones scope but no one does. Unlike a refractor, which can be twiddled with to optimize performance, a Bird-Jones is not something that can be fixed. Either you get really lucky, defy the odds and get on that's good to go, or more likely, you get something that sucks the joy out of astronomy for you. I wish mfrs would quit trying to make Bird-Jones for cheap. It's a highly improbable task.

Exactly! I like to tweak astro equipment like the next guy, but in this case it will be just waste of time.

[notFritzArgelander]

It's possible to make a good Bird-Jones scope but no one does. Unlike a refractor, which can be twiddled with to optimize performance, a Bird-Jones is not something that can be fixed. Either you get really lucky, defy the odds and get on that's good to go, or more likely, you get something that sucks the joy out of astronomy for you. I wish mfrs would quit trying to make Bird-Jones for cheap. It's a highly improbable task.

Exactly! I like to tweak astro equipment like the next guy, but in this case it will be just waste of time.

The tolerances for acceptable performance are just too tight. It is an unforgiving design that can't be made well on the cheap.

[Bigzmey]

I wish I had a good news for you, but your scope is a Bird-Jones design reflector which makes it very bad beginner scope. ... I would suggest to return or sell your scope if possible (even at loss) and get ...

Bigzmey gives good advice but this time I have to disagree. Whatever the limitations of one design over another, the best telescope is the one that gets used.

You have viewed Jupiter, Boris. Have you seen Saturn? Have you picked out its moon Titan as different from a star? Have you tried to view binaries such as Albireo? Have you tried to split the double-double in Lyra? There's a lot to see with any telescope. What books or websites are you using to plan your observing sessions? How do you keep your notebook (paper, cellphone, computer)?

It seems you are contradicting yourself Michael! Here is your thread explaining why this design should be avoided.

viewtopic.php?f=4&t=5803

Of all the inexpensive beginner telescopes on the market right now (2019), the Celestron 127 EQ is apparently the best-selling model with the Jones-Bird design. The consensus in the hobby is that this design should be avoided by the amateur astronomer.

[mikemarotta]

... It seems you are contradicting yourself Michael! Here is your thread explaining why this design should be avoided.[...]

Of all the inexpensive beginner telescopes on the market right now (2019), the Celestron 127 EQ is apparently the best-selling model with the Jones-Bird design. The consensus in the hobby is that this design should be avoided by the amateur astronomer.

The fact is that Boris already owns the telescope. You want him to take a loss on the purchase. You do not know what his economic and social circumstances are. And you want him to then buy something else with the subtext being that you will not like that one, either. "... a small refractor (80mm or larger) instead, like your friend." I can goto Amazon and find half a dozen trash telescopes that are 80mm and larger. Absent good shopping guidance how is he to know? By what standard should he judge? Celestron is a well-respected company. Colleges buy their big scopes for their observatories. Why not buy a small, affordable Celestron? How will he know that his Orion or Zhumel or Takahashi or whatever will not also be a bird-dog?

What I said is true: He needs to use the telescope he has and make the most of it. That's the bottom line.
It remains that had he done more research he would have made a different choice.

So would I.

My wife and daughter bought me a telescope for my birthday. I picked it out. I chose the Celestron EQ 130 because it most resembled the Criterion 4-inch reflector telescope I had as a kid. I finally donated it to the Goodwill. It was a bad choice. I bought a used catadioptric Meade LX-200 8-inch from the local club and donated that also because it was another bad choice.

I am settled in on my choices now. But if I had it to do all over, I would have saved a lot of time and money and grief.

That said, my observing notebook is filled with work using that Celestron EQ 130. I learned a lot. I saw a lot. The best telescope is the one that gets used.

Our local club sponsored an "open the box" night for beginners. They brought their telescopes to our dark sky site. The next day, our president emailed out a rant telling people that their finders were no good, that they had the wrong eyepieces, but here is a link to an article about buying your next telescope. The hobby killers are not the instruments.

You are not alone, Bigzmey. We can find that same sort of "you should have" all over this board and Cloudy Nights and Stargazers Lounge.

Being supportive of beginners is part of the work we do here.

[Bigzmey]

... It seems you are contradicting yourself Michael! Here is your thread explaining why this design should be avoided.[...]

Of all the inexpensive beginner telescopes on the market right now (2019), the Celestron 127 EQ is apparently the best-selling model with the Jones-Bird design. The consensus in the hobby is that this design should be avoided by the amateur astronomer.

The fact is that Boris already owns the telescope. You want him to take a loss on the purchase. You do not know what his economic and social circumstances are. And you want him to then buy something else with the subtext being that you will not like that one, either. "... a small refractor (80mm or larger) instead, like your friend." I can goto Amazon and find half a dozen trash telescopes that are 80mm and larger. Absent good shopping guidance how is he to know? By what standard should he judge? Celestron is a well-respected company. Colleges buy their big scopes for their observatories. Why not buy a small, affordable Celestron? How will he know that his Orion or Zhumel or Takahashi or whatever will not also be a bird-dog?

What I said is true: He needs to use the telescope he has and make the most of it. That's the bottom line.
It remains that had he done more research he would have made a different choice.

So would I.

My wife and daughter bought me a telescope for my birthday. I picked it out. I chose the Celestron EQ 130 because it most resembled the Criterion 4-inch reflector telescope I had as a kid. I finally donated it to the Goodwill. It was a bad choice. I bought a used catadioptric Meade LX-200 8-inch from the local club and donated that also because it was another bad choice.

I am settled in on my choices now. But if I had it to do all over, I would have saved a lot of time and money and grief.

That said, my observing notebook is filled with work using that Celestron EQ 130. I learned a lot. I saw a lot. The best telescope is the one that gets used.

Our local club sponsored an "open the box" night for beginners. They brought their telescopes to our dark sky site. The next day, our president emailed out a rant telling people that their finders were no good, that they had the wrong eyepieces, but here is a link to an article about buying your next telescope. The hobby killers are not the instruments.

You are not alone, Bigzmey. We can find that same sort of "you should have" all over this board and Cloudy Nights and Stargazers Lounge.

Being supportive of beginners is part of the work we do here.

(Wife: My husband and I just had an argument about what to cook for dinner.
Counselor: Well, clearly, you should have married someone else.)

Actually, I was in Boris shoes. My first "real" scope was poorly-made reflector. It was a long time ago before internet, so could not say for sure if it was Jones-Bird, but the chances are it was. I spent two frustrating months trying to collimate it, finally gave up, cut my losses and got small refractor. What a difference it made! So, just trying to help a fellow astronomer to avoid frustration I had. As for how Boris would know what to buy next, we are here to help him out! Also, if he goes with a refractor there is zero chance his next scope will be "bird-dog".

[mikemarotta]

Actually, I was in Boris shoes. ... Also, if he goes with a refractor there is zero chance his next scope will be "bird-dog".

Yeah, I am a 'fractor dude' too. I got tired of trying to collimate my Newtonian. That's why I gave it away, along with the collimation tool. Then, I relented, and bought an 8-inch f/4 Newtonian because it was marked down as used but factory reconditioned with a warranty (Bresser brand sold by Explore). I decided to gird my loins (as the Bible says about warfare), and I also bought a handful of different collimation tools. I have not gotten around to it yet but I am committed to the project. I just need to afford my next mount and tripod for this beefy bad boy (22 lbs = 10 kg), maybe by next summer.

The worst aspect of the collimation was not the finicky touchy work but the fatuous comments from people here on TSS and at my local club that it is easy, you can do it in five minutes, I never have a problem, blah, blah, blah. But when I asked at my local club for a collimation clinic, I was told that we don't need one because it is easy to do, you can do it in five minutes, no one has a problem, etc.

[Bigzmey]

Actually, I was in Boris shoes. ... Also, if he goes with a refractor there is zero chance his next scope will be "bird-dog".

Yeah, I am a 'fractor dude' too. I got tired of trying to collimate my Newtonian. That's why I gave it away, along with the collimation tool. Then, I relented, and bought an 8-inch f/4 Newtonian because it was marked down as used but factory reconditioned with a warranty (Bresser brand sold by Explore). I decided to gird my loins (as the Bible says about warfare), and I also bought a handful of different collimation tools. I have not gotten around to it yet but I am committed to the project. I just need to afford my next mount and tripod for this beefy bad boy (22 lbs = 10 kg), maybe by next summer.

The worst aspect of the collimation was not the finicky touchy work but the fatuous comments from people here on TSS and at my local club that it is easy, you can do it in five minutes, I never have a problem, blah, blah, blah. But when I asked at my local club for a collimation clinic, I was told that we don't need one because it is easy to do, you can do it in five minutes, no one has a problem, etc.

I don't believe it is reflector design per se, but that entry level reflectors are badly executed which in combination with lack of experience makes it even more frustrating for the beginners. If you noticed most of reflectors 6" and smaller are not kept by observers (with exception of better made astrographs). If hobby sticks most users graduate to better scope. Yet small refractors and CATs are loved and used by many even experienced observers. I still have very basic Meade 80ST purchased for ~$80 which serves several useful functions in my observing.

[Richard]

I have had many BJ reflectors , probably 10 and only one was just not fixable , that one could not focus properly after proper collimating and checking if by chance someone had flipped the corrector in the focus tube. Jupiter was as you mentioned no stripes only a blob and a star test just did not work
However not all lost as some just needed collimation and then they were OK , there are lots of forums where its explained , I just remove the corrector lens from the focuser and then collimate as a normal reflector
They are budget scopes so will never be great unless you are very lucky , out of the 10 or so I had none were great , that's why I don't have one anymore , but good luck
But since covid hit us they are not that cheap well not in RSA the Celestron 114 slt , which I could get for like 100us and did purchase a few mainly for the mount as one can mount many different scopes on it , but now people want 400us for the same

[borginz]

Thank you all very much for the discussion! I'll give collimation a chance for now, and will think about changing to a refractor as plan B.

[Baurice]

Depends on budget and interests but I have avoided Newtonians and have a Maksutov, which I enjoy very much.