9 replies to this topic

[S_Manassas]

Hoping to get some solid suggestions on essential, nice to have & not really needed "Extras"

 

I have been observing with Binos w/ my 10x50s  and I have Celestron Pro 20x80s on loan from my astronomy club.  Might try a pic or 2 but not really all that interested Astrophotography

 

For my 1st scope, I am leaning towards a 8 Celestron Evolution (USED)...there are a handful of offerings in the CN Classifieds...some with "LOTS OF EXTRAS". 

 

I would also appreciate opinions on Evolution Mount vs. AVX -I think the Evolution Mount is much simpler 

 

I am in Manassas VA

 

Thank you

[SeattleScott]

Evo mount is lighter and simpler. Has some built-ins like battery and WiFi. AVX is more versatile and can take longer tubes when you add a refractor.

You might think about a 2” diagonal or focal reducer for wider view. A dew shield or dew heater is a must. Read up on insulating tube with Reflectix, although maybe not with vents.

[Jay_Reynolds_Freeman]

You could do far worse than a Celestron 8 in any form. Another suitable recommendation that is less expensive might be an 8-inch f/6 Dobson-mounted Newtonian reflector. Now or at some future date you could upgrade it with a PiFinder (google it) (expensive but well worth it, in my experience) for very rapid location of observing targets.

 

Most commercial telescopes come with a finder and a couple of usable eyepieces -- you can hold off upgrading eyepieces till you have more experience and perhaps have had a chance to try out others, borrowed from club members at local star parties. Some sort of up-and-down adjustable observing chair would likely make observing less muscle-straining. Even if you have software star charts, I recommend a hard-copy atlas of some sort -- perhaps you already have one. And don't forget a red flashlight.

 

 

Clear sky ...

[Achernar]

A good 2-inch diagonal is a very wise choice for an 8-inch SCT. While some thread to the rear cell, I suggest buying an adapter that allows the use of a 2-inch diagonal for refractors and a 2-inch diagonal for a refractor. The diagonals that thread to the rear cell don't always hold their orientation well, and if you buy a small apochromatic refractor the diagonal will also work in it as well.  I use such an adapter and a 2-inch Astro-Tech diagonal for my 8-inch Celestron EdgeHD SCT and 80mm Astro-Tech EDT refractor. It is a good diagonal at a reasonable price.

 

I do not recommend buying a reducer unless you take photos through an SCT as I do. With a 2-inch diagonal, longer focal length wide field eyepieces will give you as much true field of view as you can get. I found trying to use them with a reducer merely leads to vignetting. The baffle tube sets a limit on the true field of view anyway. Unless you plan to take photos and need the wider field of view, they are not really necessary. SCT's are great for most applications, but low power, wide field observing is not one of them. Large binoculars though will fill that gap, and so will a good small refractor. ADM sells a huge range of accessories including dovetail rails on which you could mount a small refractor atop the SCT.

 

I also have an AVX mount. While it doesn't track well enough for long exposure imaging, it is perfectly fine for visual observing with an 8-inch SCT. It also works great with many smaller telescopes, I have used it with small telescopes such as my Orion 90mm Mak and the refractor for visual observing and Solar System object imaging. It's lightweight, easy to set up and is versatile. People have tuned them up to where long exposure imaging is possible  but if you want to do long exposure work through your SCT, get an EQ6R-PRO mount.

 

A dew cap, heater strip and controller are a must because the corrector plate is very prone to dewing up. So are a pair of power sources  one to run the mount, another to power the dew heater. The dew cap is a must even with a dew heater, you could not keep dew off the corrector without one.

 

Taras

 

"

Edited by Achernar, 14 June 2025 - 06:02 PM.

[Taosmath]

As A first scope an Evolution 8" is a great choice.  I've had 8" SCT's (Nexstar in my Case) and I had 8" dobs too.

 

The advantage of an 8" dob is a wider field of view (about 2.25 degrees). The advantage of an Evolution SCT is that it is GOTO (i.e. it will find your targets for you) and also tracking (i.e. it follows the target as it moves across the sky.  The dob should be cheaper, leaving some $ to spend on accessories), but you will need to learn to find (and track) your targets.  Personally I enjoy that but YMMV.

 

If you stick with the Evolution (no reason not to if you think it will work for you), the native field of view is about 1 degrees with the standard 1.25" eyepieces.  However if you buy either the 0.63x reducer or a 2" diagonal, as recommended by Seattle Scott, you can increase that field of view to 1.3 degrees.  I tried both and I'd recommend the reducer route - it's cheaper (~$80 for a used one),  you can use the cheaper 1.25" eyepieces as supplied with the scope and it is more compact than using a 2" Diagonal with 2" eyepieces.  The latter approach means you have a heavy diagonal and heavy eyepieces at the back of the scope.  Hence you need to slide the scope further forward in the mount to balance the scope and it can be clunky and you still might not be able to reach zenith (Though to be fair, that was a problem I encountered with my Nexstar mount - IIRC the Evolution mount has more room at the rear and is heavier duty so I maybe won't overload the mount so much)

 

You will need to learn how to collimate the SCT, particularly if you're putting it in a car to use away from home.

 

I endorse the recommendations for an adjustable height chair (I have the Catsperch 'Miniperch' https://www.wood-won...tsperch-chairs/ and find it works well for me.  There are others) a red headlight for setting up  and taking down in the dark as well as for reading charts and a hard copy star chart - I like the pocket sky atlas either the original or the Jumbo edition.

 

You've already got a club, which is the other thing I recommend, so the final thing you need is time under the stars !

 

Clear skies!

[Notdarkenough]

I would absolutely recommend the Evo over the AVX. Especially for visual observations. Alt-Az mounts provide much more comfortable viewing positions and less moving of chairs.

 

Which is recommendation #2: a good chair. I like cushioned bar stools, others like drummer's seat (like a Drummer's Throne at a music shop) while most Newt folks like adjustable height chairs like a Starbound, Vestil, or DIY Denver Chair. There are a number of threads on CN about different chair pros and cons. You will use it every session, so some thought will pay off.

 

If you plan on leaving your rig assembled in your backyard, a Telegizmos 365 will protect it all year long, increasing your viewing opportunities. If you are going to setup each session, look into SCT Insulation threads; it really does cut down on session setup times.

 

#3 recommendation is a HomeBrew control device. Google "Cloudy Nights HomeBrew". The GPS module will automate where many folks make errors, offer a much better WiFi capability, and Bluetooth. Just look into it and keep it in mind as you get going.

 

#4 is for a great planetarium program. I really like SkySafari. It is the beefed up version on SkyPortal. Again, start with SkyPortal and keep SkySafari in your mind. It let's you control your telescope with an iOS or Android device. 

 

The most important piece of kit for anyone buying a NexStar-based GoTo mount is The NexStar User's Guide. It is available at any book seller, Amazon, etc, and on the Author's NexStar Resource Site ( https://www.nexstarsite.com/ ) That site is full-of tips, links, and checklists.

 

I, too, started my own big-boy astronomy journey with an Evo 8. Enjoy!

[maniack]

Hence you need to slide the scope further forward in the mount to balance the scope and it can be clunky and you still might not be able to reach zenith (Though to be fair, that was a problem I encountered with my Nexstar mount - IIRC the Evolution mount has more room at the rear and is heavier duty so I maybe won't overload the mount so much)

 

You will need to learn how to collimate the SCT, particularly if you're putting it in a car to use away from home.

A 2" diagonal and a moderately heavy eyepiece such as the 30mm UFF is not a problem with the Evolution mount, there's enough clearance unlike the 8SE or similar Nexstar 8 setups. I wouldn't recommend the SE/Nexstar anyway for the 8" SCT unless the observer is willing to put with up a decent amount of shakiness. I went from the SE mount head to the Evolution and it's a world of improvement (and I don't even care about the WiFi or built-in battery).

 

Collimation is quite easy, there are a lot of guides and posts about this including mine (full credit to Eddgie on the process here).

 

I agree with the Evolution being a great choice here, and either the 2" diagonal or 0.63x reducer/corrector will get that full field of view. The reducer's advantages are the setup is light and it corrects some aberrations. But the spacing needs to be correct for best performance. For best high magnification detail and probably for the faintest of fuzzies the 2" diagonal might be the better choice because there isn't an additional glass element affecting the throughput of the system (and for high-mag sticking to a 1.25" diagonal is the right choice anyway). In addition for those kinds of details I've find a decent prism (including the stock Celestron unit) to perform better than a dielectric mirror in my SCTs, and reasonably priced 2" diagonals are mirrors.

 

I wouldn't consider an equatorial mount for visual. It's too much of a hassle (counterweights, polar alignment, etc.), and if you're using GoTo/tracking you don't even get to take advantage of the single-axis manual tracking in an equatorial platform.

[maniack]

You could do far worse than a Celestron 8 in any form. Another suitable recommendation that is less expensive might be an 8-inch f/6 Dobson-mounted Newtonian reflector. Now or at some future date you could upgrade it with a PiFinder (google it) (expensive but well worth it, in my experience) for very rapid location of observing targets.

 

Most commercial telescopes come with a finder and a couple of usable eyepieces -- you can hold off upgrading eyepieces till you have more experience and perhaps have had a chance to try out others, borrowed from club members at local star parties. Some sort of up-and-down adjustable observing chair would likely make observing less muscle-straining. Even if you have software star charts, I recommend a hard-copy atlas of some sort -- perhaps you already have one. And don't forget a red flashlight.

 

 

Clear sky ...

For a less expensive push-to system the Celestron StarSense Explorer system uses your phone and works quite well. It's also not that hard to adapt to other tubes. The kits can easily be found for under $200 used on eBay or Amazon.

[rjacks]

An SCT of any sort needs a dew shield and its performance is enhanced by insulating the OTA with reflectix insulation. Other than that, all you need are eyepieces and an observing chair to have fun with an Evo 8. With a 1.25 diagonal, the TV Pan 24 will give you the widest field views. If you want wider, you will need a 2 inch diagonal and 2 inch eyepieces. 

 

The focuser knob on an Evo 8 is too narrow to achieve fine focus easily. I DIYed a friction-fit wooden wheel to fit over the focus knob, and it gives me fine focus control.  

[SeattleScott]

I think we can generally agree that for visual only, SCT only, the Evo is the clear winner over the AVX. The AVX looks better if you venture into some sort of imaging, like EAA, or want to mount a longer tube like a refractor.