Refractor for rich fielduse

[Paul-F]

Hi,

I am starting to research getting a refractor as a second scope to complement my 12" LX90 .... what should I look to get that meets my criteria as in

• rich field visual use capability
  
• gets its best rich field view out of an Ethos 17mm ep
  
• a scope that I can take with me on the family holiday by car or plane (when appropriate )
  
• I may image at a later point but I don't want to pay extra for connoisseur level imaging capability
  
• Don't need goto but clock drive capability would be useful rather that a deal breaker
  
• capable of good and useful detail on planets/moon up to the usual seeing limits (not if it forces a compromise though)
  

Budget is an issue but not sure what I need to spend so this is the first foray into seeing what I need ....

[Cjg]

Hi Paul,

Have the Skywatcher 102 short tube - great for widefield views, but sure notice a lot of false colour when viewing the moon and Jupiter. That said, is a great grab and go to on the goto az mount.

Would be interested to see where your search takes you - there's some interesting apo's coming out.

Chris

[John]

I reckon a 4" ED doublet refractor with a focal ratio of around F/7 would be a nice solution. My own Vixen ED102SS is an F/6.5 and weighs just 7lbs. With the 31mm Nagler I can get a 3.9 degree true field and at the other end of the scale I can use 200x on a good night on the moon / binary stars and the planets. That scope is out of production now but I'm sure there are others of a similar spec about today.

[Paul-F]

first thoughts ...

I can purchase various OTAs only or OTA with mount/tripod ... so I get to wonder what is a a passable mount/tripod to travel with given that I will also use it in the garden for extended sessions!

Can I piggy back the scope on the LX90 when I use it at home and put up with a very basic mount when travelling ... what would that mount be, I know the sky so finding stuff aint an issue but ra tracking would be useful.

If I get a seperate mount I expect the cost will go up as opposed to getting the OTA with the mount .... Celestron Omni XLT 120mm Refractor Telescope for around £400 seems a candidate unless it is really not up to scratch that is!

[Paul-F]

I reckon a 4" ED doublet refractor with a focal ratio of around F/7 would be a nice solution. My own Vixen ED102SS is an F/6.5 and weighs just 7lbs. With the 31mm Nagler I can get a 3.9 degree true field and at the other end of the scale I can use 200x on a good night on the moon / binary stars and the planets. That scope is out of production now but I'm sure there are others of a similar spec about today.

That appeals to me - but I am wondering what an exit pupil of around 14.3 mm does to the viewing with that mag of about 21. Never looked through kit with those numbers so don't really know if it is an issue or not - I guess not as you are doing it I also have a 38mm 70 degree AFOV ep that will give about 4 degree in your kit but don't know if that is really what will happen ... if not an issue I can decide quite quickly what to get!

[ollypenrice]

If a 4 inch isn't too big then Altair Astro have a very attractive triplet at F7. Without flattener is gives great views and then for later imaging it comes with a dedicated one.

I used to grab and go with a TeleVue Gibraltar mount, which I still have. It isn't particularly marvellous in that it has no slow motion controls but it is superbly indestructible and quick to set up.

The iOptron Minitower is said to be a capable alt-az tracking and go-to mount. It was well reviewed in Astronomy Now by Ian Morrison whom we can safely say knows what he's talking about!

My own grab and go is a second hand TeleVue Pronto bought for a quarter of its new price. Stunning. I also used to have a Genesis and used TV EPs from barlowed 4.8 Nagler to 35 Panoptic very happily in that. No issues at all. Even the Pronto can show the entire Veil or Rosette.

Olly

[John]

That appeals to me - but I am wondering what an exit pupil of around 14.3 mm does to the viewing with that mag of about 21. Never looked through kit with those numbers so don't really know if it is an issue or not - I guess not as you are doing it I also have a 38mm 70 degree AFOV ep that will give about 4 degree in your kit but don't know if that is really what will happen ... if not an issue I can decide quite quickly what to get!

The Vixen ED102 / Nagler 31mm combination produces an exit pupil of 4.8mm. Quite useable even with my 50+ year old eyes

[Paul-F]

If a 4 inch isn't too big then Altair Astro have a very attractive triplet at F7. Without flattener is gives great views and then for later imaging it comes with a dedicated one.

I used to grab and go with a TeleVue Gibraltar mount, which I still have. It isn't particularly marvellous in that it has no slow motion controls but it is superbly indestructible and quick to set up.

The iOptron Minitower is said to be a capable alt-az tracking and go-to mount. It was well reviewed in Astronomy Now by Ian Morrison whom we can safely say knows what he's talking about!

My own grab and go is a second hand TeleVue Pronto bought for a quarter of its new price. Stunning. I also used to have a Genesis and used TV EPs from barlowed 4.8 Nagler to 35 Panoptic very happily in that. No issues at all. Even the Pronto can show the entire Veil or Rosette.

Olly

Had a good look at these, amongst others and I am almost settled on a 102mm scope as a good adjunct to my LX90 - I just have to decide on quality of the glass ! ED, APO or even better APO ... I am also looking for the cheapest mount that will hold the scope - goto is an unnecessary luxury right now but tracking would be useful and unlikely without the goto option on a reasonably portable mount. Since I tend to keep stuff for ages I am currently favouring getting the best optics in a 4" scope for under £1200 inc VAT and the cheapest mount that will do as an interim measure - I have a camera tripod that manages a pair of 15x70 binos and packs down nice and small, something like that but stronger would probably do ... I'll get a good mount in due course.

Can I piggyback the scope on a the LX90 for when I use it in my garden?

[thommo10]

I have also been looking for a refractor for DSO's. I quite like the Altair Astro Starwave 102ED or 110 ED with reducer/flattener,

Has anyone got any thoughts on this.

(sorry for high jacking your thread)

[Paul-F]

I have also been looking for a refractor for DSO's. I quite like the Altair Astro Starwave 102ED or 110 ED with reducer/flattener,

Has anyone got any thoughts on this.

(sorry for high jacking your thread)

--> ... looking at this one myself

I'll sleep on it but I am almost ready to pull the trigger - my main concern on this one is aperture but I need portability most tbh from this one so will 'constrain' my enthusiasm for more light gathering capability seeing as the max reasonable mag is not too far off normal seeing limits anyway.