Author Topic: Which telescope to choose?  (Read 314 times)

telschronexic

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Re: Which telescope to choose?
« Reply #30 on: January 31, 2018, 12:54:56 PM »
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Would it be possible to upgrade to the fully computerized, fully motorized mount at a later date? I would like to keep it under $800 with a $600 price tag being most comfortable right now.

Yes, you can put the dob tube on an Equatorial mount. My first scope was a 10 inch dob. 5 to six years later, I got an atlas eq mount to use with it. Worked great. Later I got other scopes that I use with that mount. As aeajr says, it is all what you are looking for. Personally I think an 8 inch dob is the best value out there. You will certainly see more detail than in a 5 inch mak, if your collimation is good. But I love maks too;-). You will likely be happy either route.

Cheers!

jmd

szenawahle

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Re: Which telescope to choose?
« Reply #31 on: February 02, 2018, 01:49:58 PM »
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So my wonderful wife bought 2 telescopes for me for xmas and is going to send one back after I choose. Both are Celestrons. The Powerseeker 127EQ and the Inspire 90AZ with smartphone adapter. I want to be able to take pictures of the moon. Any advice would be helpful in making my choice.

She even suggested I return both and put in whatever extra money I needed to to get a scope that would be a more effective use of the money. So this opens up to suggestions for scopes for a beginner that could be used for photography of the moon specifically with an additional investment of say $200 over the cost of the more expensive of the 2 above scopes.

I looked these up. With the 127EQ you might be able to try some manually driven piggyback photo with a DSLR and 50mm lens.

I probably would not like the 90AZ, unless it didn't cost much.

A 6-inch Dob will work better than either.

Matt Victorin

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Re: Which telescope to choose?
« Reply #32 on: February 02, 2018, 05:21:02 PM »
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Hi before you dismiss the 130 slt completely I would like to comment. I have this scope and it fully illuminates 2 inch eyepieces just fine I use a 31 luminos in it most of the time and it also works great with the 31 Nagler. I will admit it looks funny with those eyepieces in the focuser but they work great and the scope has no problem with them. Another point I have other bigger scopes but the 130 slt goes outside every time I set the scopes up. Good luck and enjoy whatever you get but the Celestron 130slt is a fine choice. Now back to your regular program.

I edited my earlier posting, and so to include the expanse of the view when using a 2" 32mm 70°, and as I had originally intended.

Do you think that if a mirror found within a 1.25" star-diagonal was placed into a 2" diagonal body that it would suffice still for the use of 2" oculars?

postbypopect

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Re: Which telescope to choose?
« Reply #33 on: February 02, 2018, 10:09:24 PM »
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So it sounds like, if I were to go with this smaller motorized option, I should go with the 127SLT. It also sounds like I could control this from my laptop and take pictures from there with some sort of camera attached to the eyepiece.

Let me know if I am tracking properly so far.


If your interest is "serious astrophotography" (lets say, anything other than a smartphone camera), you need to know that:

* For larger exposures (better pictures of dim objects), you need a motorized equatorial mount. This rules out alt az mount and dobsonians.
* A good camera (or sensor) costs as much or more as the telescope tube.
* A good sensor for planets is not good for DSOs, and viceversa.
* For astrophotography, the best telescopes are called "Astrographs", they are "fast" (short focal length), have corrector lenses, and more sturdy focusers to hold heavy cameras. Their mounts are equatorial, and motorized.
* You cannot get an astrophotography starting gear with less than $1500
* It takes a lot of time to learn the details on camera settings and image processing. Months to years. This on top of learning telescope use, and the sky.
* The best advice I've read here (from a 20yr astrophotography veteran) is: "just don't"

For casual pictures with a smartphone, most telescopes will do, even a dobsonian.

So, if your interest is serious astrophotography, you need to think about it carefully.

If your interest is observation, with a side of casual moon/Jupiter pictures with a smartphone, then you need to figure out your portability requirements, and then get the scope with the largest aperture that still meets those portability requirements, is within your budget, and features the navigation you want (push to, go to, or manual).

My dream scope for urban watching with occasional road trips is the SkyWatcher Collapsible dobsonian. The 8" model goes for $449

hiswacoka

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Re: Which telescope to choose?
« Reply #34 on: February 03, 2018, 07:56:03 AM »
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Hi before you dismiss the 130 slt completely I would like to comment. I have this scope and it fully illuminates 2 inch eyepieces just fine I use a 31 luminos in it most of the time and it also works great with the 31 Nagler. I will admit it looks funny with those eyepieces in the focuser but they work great and the scope has no problem with them. Another point I have other bigger scopes but the 130 slt goes outside every time I set the scopes up. Good luck and enjoy whatever you get but the Celestron 130slt is a fine choice. Now back to your regular program.

I edited my earlier posting, and so to include the expanse of the view when using a 2" 32mm 70°, and as I had originally intended.

Do you think that if a mirror found within a 1.25" star-diagonal was placed into a 2" diagonal body that it would suffice still for the use of 2" oculars?
The celestron 130 slt has a 43mm secondary mirror listed at a 33% obstruction ,

rentireacen

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Re: Which telescope to choose?
« Reply #35 on: February 09, 2018, 07:57:23 AM »
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The celestron 130 slt has a 43mm secondary mirror listed at a 33% obstruction ,

That measurement corresponds precisely to the clear aperture of this 2" prism diagonal...

http://www.apm-teles...oadband-coating

...and there was a recent discussion of the APM being somewhat inadequate for 2" oculars. The clear aperture of the Baader 2" prism diagonal is 47.5mm.

A secondary mirror is also known as a "diagonal", in and of itself.

Ryan Hernandez

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Re: Which telescope to choose?
« Reply #36 on: February 09, 2018, 09:27:25 AM »
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If your interest is "serious astrophotography" (lets say, anything other than a smartphone camera), you need to know that:

* For larger exposures (better pictures of dim objects), you need a motorized equatorial mount. This rules out alt az mount and dobsonians.
* A good camera (or sensor) costs as much or more as the telescope tube.
* A good sensor for planets is not good for DSOs, and viceversa.
* For astrophotography, the best telescopes are called "Astrographs", they are "fast" (short focal length), have corrector lenses, and more sturdy focusers to hold heavy cameras. Their mounts are equatorial, and motorized.
* You cannot get an astrophotography starting gear with less than $1500
* It takes a lot of time to learn the details on camera settings and image processing. Months to years. This on top of learning telescope use, and the sky.
* The best advice I've read here (from a 20yr astrophotography veteran) is: "just don't"
Hi Dale,
As I said in an earlier post, you would likely get inundated with advice:-) For my 2 cents I would agree with these points made above, if your expectation is to generate an APOD(astro picture of the day) picture. That is certainly a worthwhile mark to aspire too, and you will likely spend a heck of a lot more than 1500 Dollars getting there!!:-).

However, it is certainly possible to get cool images from a wide range of objects with much more simple gear.  Solar system, Moon, Sun, Saturn Venus and Mars are absolutely doable with a dob, a 100-200 dollar camera and a great deal of planning, PRACTICE and patience.

An example is herehttps://www.flickr.c...in/photostream/

This is a mosaic of images taken of the moon in an 8 inch dob with a 90 dollar Orion planet cam and a barlow. This gentleman now uses a C8 on tracking mount, but he started out with an XT8 dob and that little camera. All of mr. Varney's early work was done with the dob. Some of it used a tracking platform that he built from a kit, but a lot of the early images did not. If you go through his flicker account you can see the evolution of his imaging as he learned to use the camera, scope and image processing techniques.

I provide this example as a point of encouragement.  You can get started with a "relatively" small investment, and learn the basics of astrophotography, including how to find what you are looking for, how to tell if your scope is collimated, how to collimate your scope when it isn't well collimated, how to adjust gain and exposure time. How to stack images, Why you stack images, and the list goes on...  If you spend the time to learn all these skills using economical gear and "simple" targets like the moon or jupiter to get the very best image you can get with your gear, you will have an excellent foundation that justifies investing in more sophisticated equipment to image more challenging objects like fainter DSO's.

If on the other hand you come to the conclusion that imaging is a big PITA(not an unreasonable conclusion:-), and that both Orthoscopic and Wide field Eyepieces are really cool, then you have saved money to invest in some good EP's.

Astronomy, visual or photographic, is really a discipline and it takes time, effort and commitment to master either one. As you get better at it, you will likely want to add to and/or upgrade your gear. Just like any other hobby. And just like most other hobbies, there is ALWAYS more cool gear to be had and no limit to what you could spend:-)  The key is to be happy with what you are doing at the time you are doing it!  Set little goals that you can strive toward during an observing session so you can feel a sense of accomplishment, and First and foremost ENJOY things!  If you find your self getting frustrated, take a step back and look up at the sky. Drink in the quiet of the night. Pull out your favorite Eyepiece and look at stuff for a while. I like imaging, but I can also loose myself for 40 minutes just scanning around the moon with one on my eyepieces. 

I hope that you have found encouragement from all the advice everyone has provided. I think the key threads running through it all are that you should take your time, figure out what you are really interested in, and understand that if you really get into the hobby, you will likely end up spending more money on gear:-) To that end, any of the suggestions of scopes and mounts made here will enable you get started with a solid foundation.

Good Luck!

JMD