Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Celestron 130SLT and ZWO ASI1600MM


Recommended Posts

It should be ok... I use a DSLR with a filter wheel on a SCT and its fine...

the DSLR sensor is further back in the body comparing to the ASI1600, so I'm sure it'll be fine.

Probably comparable back focal length to a DSLR without a filter wheel and others have achieved focus with a DSLR on a 130SLT.

Link to post
Share on other sites
  • 3 months later...

When I was a freshman in college, one of my first 'scopes was a used Celestron PowerSeeker 127mm, which is very close to your Celestron 130mm. It seemed okay, at first but once I joined clubs and started using other 'scopes, the Celestron 127mm literally became the worst one. I found that, by comparison, the primary mirror was outright horrible. It was dirt cheap and "blurry." They also suffer from aberrations. The focuser was also junk. I sold the entire EQ 'scope for $30, which is, what I paid. However, I learned how to use altitude & azimuth, ect.


Do you want the truth or a lie? Here it goes, the SLT 130mm has a good focal ratio and a descent aperture size for astrophotography but that's it. If it's anything like the 127mm, it is probably ... Don't get the wrong impression, any 'scope is better than none but those mid sized Celestron reflectors are "brutal." I can see, why you chose it, for imaging & some DSO spotting around but the mirrors and focusers are real poor quality - rough. Atleast, that's how it was a few years ago. Instead, I would have gone, with a 90-127 mm MAK and used the MAK for observing. MAKs are alot of 'scope; cassegrains are the most advanced.
Your camera is super expensive but your primary mirror has low quality. It is comparable to like a Bushnell Northstar and the cheap kids sets. A $30 'scope & $1,000 camera is ironical? 
 

Link to post
Share on other sites
37 minutes ago, Science562h said:

When I was a freshman in college, one of my first 'scopes was a used Celestron PowerSeeker 127mm, which is very close to your Celestron 130mm. It seemed okay, at first but once I joined clubs and started using other 'scopes, the Celestron 127mm literally became the worst one. I found that, by comparison, the primary mirror was outright horrible. It was dirt cheap and "blurry." They also suffer from aberrations. The focuser was also junk. I sold the entire EQ 'scope for $30, which is, what I paid. However, I learned how to use altitude & azimuth, ect.


Do you want the truth or a lie? Here it goes, the SLT 130mm has a good focal ratio and a descent aperture size for astrophotography but that's it. If it's anything like the 127mm, it is probably ... Don't get the wrong impression, any 'scope is better than none but those mid sized Celestron reflectors are "brutal." I can see, why you chose it, for imaging & some DSO spotting around but the mirrors and focusers are real poor quality - rough. Atleast, that's how it was a few years ago. Instead, I would have gone, with a 90-127 mm MAK and used the MAK for observing. MAKs are alot of 'scope; cassegrains are the most advanced.
Your camera is super expensive but your primary mirror has low quality. It is comparable to like a Bushnell Northstar and the cheap kids sets. A $30 'scope & $1,000 camera is ironical? 
 

The Powerseeker 127 and SLT130 are totally different animals, the only thing they share is the brand name. The PS127 uses a spherical primary mirror and a corrector lens built into the focuser to correct spherical aberration and increase the focal length to 1000mm. This design is known as a Jones-Bird or barlowed reflector. The SLT 130 is a classic Newtonian reflector which employs a parabolic primary.

Link to post
Share on other sites

In the 1700's (1762), Newton built the first reflecting telescope that was 40x and had a 1.3" mirror. That's my point, old scientific technology, with a super-modern camera. I haven't used the 130mm. I gave up on mid sized reflectors and just went, with a MAK, at the same size; well, 127mm, you know, what I mean. Reflectors are better light collectors indeed but there is a price to pay. It blocks light (about 10%) and still suffers from spherical aberrations. The block isn't that big of a problem and some 'scopes are better than others. I looked, through a Bushnell, I was curious and my goodness, blurry.

That's good to know, it uses a corrector plate. Good. Regular concave primary mirrors can be corrected, by shaping the mirror and lenses. The reflector can use a parabolic mirror, which increases the concave and thickness of the edges or add a Schmidt corrector plate. I see, the Jones-Bird type corrector. I just use "corrector plate" in general.  

- Aviation Electrician, with NASA teachers from the actual control room


   

 

 

 

 

Link to post
Share on other sites
On ‎20‎/‎05‎/‎2018 at 04:48, Science562h said:

In the 1700's (1762), Newton built the first reflecting telescope that was 40x and had a 1.3" mirror. That's my point, old scientific technology, with a super-modern camera. I haven't used the 130mm. I gave up on mid sized reflectors and just went, with a MAK, at the same size; well, 127mm, you know, what I mean. Reflectors are better light collectors indeed but there is a price to pay. It blocks light (about 10%) and still suffers from spherical aberrations. The block isn't that big of a problem and some 'scopes are better than others. I looked, through a Bushnell, I was curious and my goodness, blurry.

That's good to know, it uses a corrector plate. Good. Regular concave primary mirrors can be corrected, by shaping the mirror and lenses. The reflector can use a parabolic mirror, which increases the concave and thickness of the edges or add a Schmidt corrector plate. I see, the Jones-Bird type corrector. I just use "corrector plate" in general.  

- Aviation Electrician, with NASA teachers from the actual control room

 

Sir Isaac Newton died in 1727, 31 March 1727 to be exact. Newton is generally credited with making the first practical reflecting telescope in 1668 (not 1762), although there were other attempts to produce a reflecting going back as far as 1616. James Gregory in 1663, for example, published a design for a reflecting telescope (Gregorian Telescope) but was not made until 1673 by Robert Hooke.
Your view of 130mm reflectors is clouded by a bad experience with a PowerSeeker 127, no one has a good experience with cheap Jones-Bird reflectors. They are not strictly Jones-Birds, a J-B places the corrector between the primary and secondary. Take a look in the "Getting Started with Imaging" section and go to the Imaging with the 130PDS  thread to see what can be achieved with a small Newtonian.

 

  • Like 1
Link to post
Share on other sites
  • 2 years later...

The 130SLT is not a bad telescope but the best thing about it is the mirror, The focuser wants to be taken apart, cleaned and serviced; some soft grease used, and the tension adjusted so it moves smoothly. The nylon bars on the slide may want packing with tape to reduce slop. The focussing is rack and pinion, and quite coarse, but by adding a long lever to one of the knobs, such as a battery crocodile clip can move it in small doses. Have the lock screw just touching whilst focussing to reduce slop, nip it lightly once in position.

The problem with 'back focus' (which means something else to photographers) aka 'flange focal distance' means the camera needs to be moved in or out from the the eyepiece/Barlow. Typically the sensor needs to be at the distance your eye would be.  This may be done with extension tubes, an eyepiece projector, longer or shorter camera adapters, or even a focussing eyepiece adapter. A DSLR has a mirror box, a mirrorless camera does not, an eyepiece camera (ZWO etc) can be moved on its stop ring. This distance is not super critical as then the whole lot is focussed on the telescope.  Experiment.

The 130SLT eyepiece adapter may even be fitted on the underside of the plate, allowing a Barlow or nosepiece T2 adapter to drop further inwards, saving that the clamp screws are too long and would have to be replaced with shorter ones or grub screws. I've tried this with the screws out, loose, it kinda works.

An Olympus E-M5ii can for example achieve prime focus mounted directly on the 1.1/4 eyepiece adapter of the 130STL with a thin T2-MFT adapter; most MFT adapters have an extension tube to allow for the missing mirror box when adapting a camera lens.  A different length tube may be needed to mount it onto a Barlow. Tubes and adapters are available in different lengths.

The NexStar 130SLT does not have powerful motors and cannot support much weight on the nose of the OTA, a suitable tube ring may be used at the back end to counter balance the additional mass.

Link to post
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.