Choosing my Next Telescope

[AstroExploring]

Hi everyone! 
A bit of context. I’ve been imaging with the Sky-Watcher Evostar 72ED for nearly 2 years now. I’ve been happy with the images I’m getting with this scope and DSLR but feel it’s time for a change. 
The natural progression that I felt was right was to buy a dedicated astronomy cam but I feel the telescope is the next obvious choice because my scope is the older model with the longer tube assembly and so I can’t use 2 inch filters with it, which puts me at a bit of a disadvantage as I’d be left with a great camera, decent scope but light polluted images. 

I need help deciding which scope to get and I’m hoping the collective experience of SGL might offer some advice. The purchase is purely down to future proofing my setup so that I can use 2 inch filters and a dedicated astro cam when I have more funds available. 

Sky-Watcher Evostar 80ED. Basically the same scope with a slightly longer FL but with the option of using 2 inch filters. The advantage to this one is that it’s cheap and I already have the FF for it as the 72ED uses the same one. Downside is it doesn’t feel like a long term scope for me, or much of an upgrade. 

WO Z73. More expensive, same FL, same glass as 80ED but I hear a lot of people talking about the quality of a WO scope, which I assume justifies the increased cost and why they’re so popular. Is this really a better scope than the Sky-Watcher 80ED? Hoping somebody more informed can tell me. 
 

WO GT71. The most expensive choice but it’s a triplet. Feels like the most long term solution for me but leaves me with not much left in the funds for extra gear so buying that astro cam would be a while off if I went for this scope. How good quality is this triplet? I assume a top quality doublet is better than a low quality triplet? 
 

I have the funds available for any of the telescopes, and I’d sell my 72ED too, but I don’t necessarily want to deplete all my funds just because I have the money available. I’m also open to other scopes if people have other suggestions. 
 

Thanks in advance

Nick

[The Lazy Astronomer]

Question (and it may be a stupid one - apologies if so), but why specifically the requirement for 2 inch filters?

Side note: the lightness of my wallet tells me the biggest mistake I've made recently is asking this forum what telescope to get next!! 😁

[johninderby]

You might also consider this scope by Tecnosky.  Similar quality to the WO.

https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGTEC80F6

Edited March 26, 2021 by johninderby

[EntropyTango]

Most of the scopes you are considering are just slightly bigger refractors.

I understand as I am a big refractor fan as well.

But how about an RC or Newt-Mak, something that gathers more photons and a longer FL?

[Stu]

6 hours ago, EntropyTango said:

Most of the scopes you are considering are just slightly bigger refractors.

I understand as I am a big refractor fan as well.

But how about an RC or Newt-Mak, something that gathers more photons and a longer FL?

A lot depends on what mount the OP has, and what targets he is after capturing I guess.

[AstroExploring]

Thanks for the replies so far. Just to clarify a few things:

• The requirement for 2 inch filters comes from wanting to upgrade to a dedicated astro cam soon. At the moment I have a couple of clip in DSLR filters, and I don't want to keep buying clip ins as I'll need to buy them again later when I get an astro cam.
• The mount I have is an HEQ5 (belt modded)
• Why a refractor? Just personal preference atm tbh. It will be my only scope so I want it to be a refractor, if it was a second scope I would look into other scope types like an RC or Newt-Mak 🙂
• In terms of targets I like to capture, I'm a big nebulae fan and enjoy capturing those the most. I do like imaging galaxies too but less so at the moment (though that's probably down to the limitations of the FL of the scope). No planetary at this time, that's a whole different rig entirely 😃

[Sp@ce_d]

So the topic is scopes.. From what you've listed I'd just say Esprit 80 & be done with it

wandering OT slightly.. you're talking about 2" filters.. now bear in mind that none of the scopes talked about so far will cover a sensor larger than one's that can't be used with 36mm filters. The size of which requires 2" filters (full frame?)

So, normally spend money in this order...  Mount, Scope with well corrected optics FL/FOV for intended targets etc., imaging device + filters... etc.

[The Lazy Astronomer]

3 hours ago, AstroExploring said:

The requirement for 2 inch filters comes from wanting to upgrade to a dedicated astro cam soon. At the moment I have a couple of clip in DSLR filters, and I don't want to keep buying clip ins as I'll need to buy them again later when I get an astro cam

You don't need 2 inch filters unless you're planning to go with a full frame camera (and those are £££££).

With a 4/3 sensor size you can actually get away with using 1.25" filters up to about f5, presuming you're able to get the filter close to the sensor (there is some vignetting, but corrects out with flats). If you were looking at aps-c size, then you'd really only need 36mm filters.

If you're happy with your scope, I'd say keep it and go straight for dedicated astro cam (and go mono!)

[vlaiv]

I happily use 4/3 sensor with 1.25" filters at F/4.8.

In any case, how about going a bit bigger - say 4"? There are very fine triplets out there in 4" range for imaging.