Beginner Scope on AVX GEM- SCT vs Newt

[Meia]

Hello All,

After reading countless posts on this forum and other about the debate between what is better between SCTs and Newtonians scope, I decided to create my account and to ask the same question but with the scopes I am looking at.

To begin with, I know how to indentify the major stars and some constellations. I have been to black sites before and did wide angle photography of the milky way with a Sony a6000 but never ever owned a telescope/tracking mount. I did however do some binocular observing (7*50).

Now regarding the scopes and mount.

- I am pretty set on getting an AVX mount due to its go to functionality, which would allow my family to also use it. The fact that it is also a GEM mount as opposed to alt-az would allow me to do longer exposers with my camera. And maybe take a few pictures of stars thought the telescope. However this is not the main objective.

- Scope wise, I am looking at a well rounded Celestron and more specifically at the ones bundled with the AVX mounts.

The 3 in my budget are:

- 6' SCT

- 6' Newtonian

- 8' Newtonian

That being said I have read good and bad things about these 2 types of telescopes. Are Newtonians that cumbersome and is the eye piece truly in a terrible possition on GEM mounts?

Are SCTs, which yes gather less, that much underperforming as all around scopes due to dew and cooling ( that being said I live in a rather dry climate)

So while the 8 newtonian would definitely offer the best viewing experience, would the functionality of an 6 SCT outweight the inconvenience of the eye piece location of a newtonian on a GEM?

How about the 6 SCT vs 6 newtonian?

I know that i could probably get a dosbonian with a bigger aperture for far cheaper but the goal here is to have a we'll rounded mount that would allow me to accommodate both Newtonians and SCTs depending on where I want to go from here.

Edit- also quick question, would it be worth it to keep the included eye piece until I am comfortable with the scope or would you recommend getting a few ones for more viewing enjoyment?

Thanks!

Meia

[happy-kat]

Welcome

I'd pick the SCT for shared family viewing for the eyepiece position.

There's bound to be plenty replies.

[RT65CB-SWL]

Hi Meia and welcome to SGL. 

Also with an SCT or Maksutov telescope, the image in the eyepiece will be the 'right way up'. 

[Meia]

Thank you for your replies!

Seems like the SCT has the edge for now. Now I guess, if I go for a SCT, would you say that the 6' would give me plenty to work with for a while before upgrading or would you recommend to wait before getting it and go for a 8' when I will have saved enough?

[Handy_Andy]

With regards to your idea of having an 8" Newtonian on your Avx I would suggest caution. Whilst the mount can manage the weight, the slightest gust of wind moves it around quite a bit meaning that you'll be limiting your viewing opportunities to only perfect conditions 

[Demonperformer]

Hi, Meia, and welcome to SGL.

I owned a 6SE (an sct type scope) for several years before upsizing to an 8". I also spent many years prior to that using nothing more than 7x50 bins.

Based on that, I would say that the views you get with a 6" will blow you away, particularly if you are able to have limited LP, or are able to get to somewhere that has limited LP. Yes, the 8" will give you twice the light grasp and, to some extent, will bear higher magnification, but that is often limited more by the atmospheric conditions than the optics.

If I were to go back to 2009, faced with your decision, would I still purchase the 6" or wait until I could afford the 8"? No question - I would go for the 6" now. It will definitely give you "plenty to work with" for a while.

[PeterCPC]

Get the biggest that you can afford. An SCT will also give you the chance of doing planetary imaging in the future. I find my AVX to be very stable.

Peter

[Meia]

Would you recommend to just use the 20mm eyepiece that comes with the scope or get additional accessories?

I did read the post pined in this section which says which piece to get for a certain aperture but unsure if they are worth getting from the get go.

[Demonperformer]

Start with the basic package that comes. Depending on what targets most appeal to you, you will quickly find that you want something "more" (more magnification, more field of view, etc). When you know the result you want your new purchase to give you, we will be able to give more directed advice on what to go for.

Eyepieces in particular can become addictive and they are also a money-pit. And, of course, it is always easy for us to spend your money .

[des anderson]

Get the 6" and the AVX a great combo. I`ve got a 9.25 on an AVX and its just awesome and when i go to a dark sky area I take my 6" with me, yep I know I loose light grasp, but its so portable. If and when you want to get a couple of extra eyepieces go for a couple around the 12/ 15mm and one around the 30mm, this will give a good range of magnification which will suit the scope nicely. hope this helps, Des

[RT65CB-SWL]

As above. The C6/SCT is an awesome 'scope for ease of use, weight, transportation etc. Below is a photo of my C6 xlt alongside my ETX 105

 

If you have enough pennies left over, than you may wish to consider a focal reducer which will turn the f/10 of the C6 into an f/6.3 'scope which is a bonus if you want to get some photos.  Another optional accessory to consider would be a Crayford focusser. I use a single speed on both 'scopes, though in hindsight, a dual speed may have been a better option. 

 

[Cosmic Geoff]

The question I am always tempted to ask about a Newtonian is "Why?".  Yes, they are cheaper than an SCT, and you can have a shorter focal ratio, which may or may not be useful depending on what you want to do with it.  But you have to mount it... and they are long, heavy and the eyepiece can get into awkward positions.

Likewise with an equatorial mount: "Why?" If you only intend to use the telescope visually, an alt-azimuth mount will be less of a bother all round.  But if you have (planetary) astrophotography in mind, an equatorial mount will be worth having.  Also the alt-az GoTo mounts tend to be made for portability rather than stiffness. 

Dew - SCTs require a dew shield.  Cooling - not a big issue especially if you can plan ahead e.g put it outside to cool, or do low-resolution tasks first.

[Demonperformer]

I think you have answered your own questions here. A short focal ratio is good (generally) for AP and an EQ mount is essential for AP.

For visual observing (& SS imaging) an alt-az is much simpler, but move onto DSOs and it suddenly becomes a massive limitation, not least because they are "made for portability rather than stiffness". And, of course, field rotation. Believe me, I spent years fighting this necessity because of a bad experience with a (cheapish) eq-mounted scope in the dim and distant past.

I wonder if this might all be changing, however, with the new CMOS cameras that have been making their way onto the market. So many good images on the internet that have been taken using one of these - thousands of subs that are only a few seconds long (by which I mean <5). But there is still the issue of field rotation.

[Geoff Lister]

10 hours ago, Demonperformer said:

But there is still the issue of field rotation.

Perhaps this remaining problem has a solution. As I understand it, from the user manual (middle of page 88 in the V29 version), the Sharpcap software has the ability to compensate for field rotation, based on the positions of the bright stars in each of the short-duration frames. As an occasional imager, with Az/Alt mounts, this fills me with enthusiasm.

[Demonperformer]

Yes and no. Software can correctly position frames over one another (stack them), but the frames will be rotated to achieve this. The end result over a long period is that you end up with a circle in the middle that is fully exposed and bits round the edge that are only partially exposed - which introduces problems of its own. The simple solution to this is to crop the field so that it only contains the fully-exposed bits, but then you have to judge the field you are imaging with that in mind.

But yes, for objects that are significantly smaller than the field you are shooting, this will work over short durations as long as the individual exposures are short enough to avoid trailing at the edge of the bit you want to keep.

[Meia]

Thank you all for the answers. I will go ahead and buy a 6" SCT and the avx mount I will look at the suggested lenses and focal field reducer after I get the telescope and get the hang of it.

[Meia]

For those of you wanting to buy a telescope from Celestron and happening to read this:

From now to April 29, Celestron offers 15% off of your order for up to $100. Promo code is PARKS

[RT65CB-SWL]

On 20/04/2018 at 15:34, Geoff Lister said:

Perhaps this remaining problem has a solution. As I understand it, from the user manual (middle of page 88 in the V29 version), the Sharpcap software has the ability to compensate for field rotation, based on the positions of the bright stars in each of the short-duration frames. As an occasional imager, with Az/Alt mounts, this fills me with enthusiasm.

That's interesting. I too have the urge to do some imaging with my alt-az setup.