Advice on a picking a refractor

[dweller25]

I exchange my 4” F/8 refractor between the SW AZ4 for grab and go and the Vixen GP equatorial (similar to SW EQ5) for high power tracking.  Both mounts hold the scope well.

[John]

I've used both equatorial mounts and alt-azimuth mounts with my 4 inch, and larger, refractors. Both types worked well but I've currently moved to alt-az mounts for all my scopes for 2 main reasons - I want to keep my setups as light as possible (while still stable) and I like to have the simplest possible setup, operation and take down routines.

As has been said though, there is no right or wrong approach to this - it's just personal preference.

 

[Guest]

Time to hit the local astro club up and look at some toys.  

[John]

1 hour ago, Mike Q said:

Time to hit the local astro club up and look at some toys.  

Most of the members of my astro club, that actually have telescopes, have SCT's 

I think I'm considered a bit of a curiosity with my refractors 🙄

[Guest]

14 minutes ago, John said:

Most of the members of my astro club, that actually have telescopes, have SCT's 

I think I'm considered a bit of a curiosity with my refractors 🙄

I will be in your boat soon enough.  I want something that compliments my 10 and 16 inch dobs.  Eventually i will get behind both a SCT and a frac.  Pros and cons either way you go.  I just want something different and slower.  

[The Lapwing]

On 05/06/2023 at 23:21, mikeDnight said:

I'd go for the Starfield 102ED in a hear beat. The Starfield will give you both rich, wide, low power vistas, while also offering piercingly sharp, clean, high power views of double stars. The Planets and Moon will be crisp with great contrast and definition. You may even be pleasantly surprised at how bright many deep sky objects look through the 102ED.  A 4" refractor can be an awesome companion as it is easy to set up, quick to reach thermal equilibrium, and is a great all round performer. It would also give pleasing images!

Like Mike said. FLO have 2 left and Altair have not had them in stock for months. Best value you are going to find for a 4 inch refractor 

[The Lapwing]

49 minutes ago, John said:

Most of the members of my astro club, that actually have telescopes, have SCT's 

I think I'm considered a bit of a curiosity with my refractors 🙄

Me too. I’m alright with it 😎

[Ratlet]

1 hour ago, John said:

Most of the members of my astro club, that actually have telescopes, have SCT's 

I think I'm considered a bit of a curiosity with my refractors 🙄

Meanwhile I'm just curious.  Like I understand what sharp means from a descriptive point of view, but astronomy seems to be a hobby of 'greater than the sum of its parts'.  Seeing Jupiter with good contrast, seeing globs with the 10" Vs the 5".  Heck clusters in general!  You can describe them, but the words don't really do justice to the view.  More than once I've sworn at the eyepiece or just started laughing.

Sounds like I'll be in a good place to hit the ground running with it if I pick up a diagonal.  My Gem28 has been languishing underutilised so it'll hopefully be happy to get some use.  I

Got some time to wait yet.  Light nights and still waiting for the credit card to cool down.

Unfortunately my shift pattern doesn't match up with the Aberdeen astro events or I would have a look.

Fortunately the forum hasn't steered me wrong on a purchase yet.  

[Guest]

1 hour ago, Ratlet said:

Meanwhile I'm just curious.  Like I understand what sharp means from a descriptive point of view, but astronomy seems to be a hobby of 'greater than the sum of its parts'.  Seeing Jupiter with good contrast, seeing globs with the 10" Vs the 5".  Heck clusters in general!  You can describe them, but the words don't really do justice to the view.  More than once I've sworn at the eyepiece or just started laughing.

Sounds like I'll be in a good place to hit the ground running with it if I pick up a diagonal.  My Gem28 has been languishing underutilised so it'll hopefully be happy to get some use.  I

Got some time to wait yet.  Light nights and still waiting for the credit card to cool down.

Unfortunately my shift pattern doesn't match up with the Aberdeen astro events or I would have a look.

Fortunately the forum hasn't steered me wrong on a purchase yet.  

So just how do you describe the Orion Nebula to someone, or even good old M13.   We get lots of "Oh Wows", but ask someone to describe it.... Forget about it lol. 

[Franklin]

3 hours ago, John said:

I think I'm considered a bit of a curiosity with my refractors 🙄

You can't blame them really, sitting on your sofa with a 6" Istar on your lap!😁

 

[Ratlet]

6 hours ago, Mike Q said:

So just how do you describe the Orion Nebula to someone, or even good old M13.   We get lots of "Oh Wows", but ask someone to describe it.... Forget about it lol. 

Brewing and astronomy are the two hobbies that have really gripped me in my lifetime and there is one thing I've noticed in common with both is that the folk who are passionate about it, when they talk about it it's not so much what they say, rather how they say it.

You can feel the excitement rising in them.  Writing it down doesn't quite capture it because it's so hard to really get it in words.

Oddly it's usually the first couple posts people make when they start observing or sketching that really capture it for me.  My favourite thing to see on the forum is a post "First observing report" or "First time sketching".  They're always a treat.

[Ratlet]

6 hours ago, Franklin said:

You can't blame them really, sitting on your sofa with a 6" Istar on your lap!😁

 

I think someone put that across his lap to stop him from escaping!  That's a fair size size of scope.  I think it might be a fair size of a human too!

[Alan White]

10 hours ago, Franklin said:

You can't blame them really, sitting on your sofa with a 6" Istar on your lap!😁

 

Clearly its just a very small sofa 😉

 

[grjsk]

Since most here seems to advocate for the 102mm, let me argue the case for a smaller refractor. There is not a correct answer here, it really depends on your priorities. But I have owned a 72mm, 90mm and 102mm refractor, and I have kept only the 72mm.

A 72mm doublet is about 2,2kg. A 102mm is 4,2kg. Not a massive difference, but they require vastly different mounts. My 72 rides on a az-gti with a sturdy carbon fiber triod. The whole thing is a little over 5kg but is still very steady. A 102mm needs at least a az4 or az5 on a steel tripod imo. That’s 7-8 kg. I probably would have preferred it on a Skytee 2 or something similar. Thats 10kg. So we are talking 14kg + in total. That's a significant difference.

 

The 102mm gathers 2x as much light as the 72mm. That sounds like a lot. But a 10mm gathers 2x as much light as a 7mm to. I doubt anyone would see the difference. A 300mm gathers 2x as much light as a 210mm. 90mm difference = significant. 30mm however?

Now, I think our eyes, experience, seeing  etc plays a big role here. I have read that many on SGL and Cloudy Nights thinks they see A LOT more in a 4 inch vs a 3 inch. That was not my experience comparing my 72mm with the 90mm this winter, and therefore I sold the 90mm.

 

Bottom line: to me the much lighter weight easily beat out the extra mm of aperture. Everything fits onto a small backpack. But if the weight and size difference doesn’t bother you, the 102mm is probably the right call.

[John]

9 hours ago, Ratlet said:

I think someone put that across his lap to stop him from escaping!  That's a fair size size of scope.  I think it might be a fair size of a human too!

It was a very large scope and I was large as well - I have thankfully lost around 3 stone since then 🙄

The scope has moved on as well - it was just too long and heavy so finding a suitable mount was a headache and then getting the scope safely on and off the mount was a backache. The photo below shows it in comparison with my ED120 and ED102 refractors.

I learned quite a bit from that experience though 🙂

 

 

 

Edited June 8, 2023 by John

[Ratlet]

3 hours ago, John said:

It was a very large scope and I was large as well - I have thankfully lost around 3 stone since then 🙄

The scope has moved on as well - it was just too long and heavy so finding a suitable mount was a headache and then getting the scope safely on and off the mount was a backache. The photo below shows it in comparison with my ED120 and ED102 refractors.

I learned quite a bit from that experience though 🙂

 

 

 

Blooming heck!  That looks even bigger now!  Not grab and go that one.

I remember watching (I think) astrobiscuit who was speaking to someone who had something similar.  Said he hadn't looked through it because he couldn't physically lift it.  What was the focal length on yours?

Nice Vixen.  Classic styling on that.

[John]

29 minutes ago, Ratlet said:

Blooming heck!  That looks even bigger now!  Not grab and go that one.

I remember watching (I think) astrobiscuit who was speaking to someone who had something similar.  Said he hadn't looked through it because he couldn't physically lift it.  What was the focal length on yours?

Nice Vixen.  Classic styling on that.

Mine was F/12 so 1800mm focal length. I did get it mounted and used it a few times. Optically it was excellent but even an EQ6 mount on a massive tripod with 3 inch steel tube legs was not really up to the job of holding it really steady for high power observing. I came to the conclusion that refractors of this type are better permanently mounted in an observatory. It was fun trying one, all the same 🙂

 

Edited June 8, 2023 by John

[bosun21]

34 minutes ago, Ratlet said:

Blooming heck!  That looks even bigger now!  Not grab and go that one.

I remember watching (I think) astrobiscuit who was speaking to someone who had something similar.  Said he hadn't looked through it because he couldn't physically lift it.  What was the focal length on yours?

Nice Vixen.  Classic styling on that.

The one on the Astrobiscuit video was a 7” and was too heavy to pick up.

[Guest]

19 minutes ago, bosun21 said:

The one on the Astrobiscuit video was a 7” and was too heavy to pick up.

Here.... Hold my beer.  Challenge accepted.  

[bosun21]

2 hours ago, Mike Q said:

Here.... Hold my beer.  Challenge accepted.  

Have a look at it (2.40).

 

[Guest]

24 minutes ago, bosun21 said:

Have a look at it (2.40).

 

No problem. I have a engine cherry picker.  We will get that thing off the ground.....And in one piece too LOL.  I will admit that thing is a pig

[John]

3 hours ago, bosun21 said:

The one on the Astrobiscuit video was a 7” and was too heavy to pick up.

8.5 inch maybe - it, or one very like it, is currently for sale (I think this is the same scope):

8.5" F/12 achromatic refractor and EQ8 equatorial mount and steel pier | eBay

 

 

 

Edited June 8, 2023 by John

[John]

3 hours ago, Ratlet said:

.....Nice Vixen.  Classic styling on that.

Thanks. It's the ED102SS F/6.5. It dates from 2000 and is broadly similar to the Starfield 102ED.

4 inch refractors are very useful instruments - I have a couple of them ! 🙄

[Ratlet]

35 minutes ago, John said:

8.5 inch maybe - it, or one very like it, is currently for sale (I think this is the same scope):

8.5" F/12 achromatic refractor and EQ8 equatorial mount and steel pier | eBay

 

 

 

I love the description "Would consider a quality part exchange. Must be smaller..."

I do like the look of Vixens, from a purely aesthetic point of view I prefer them to another popular Japanese scope that will remain nameless.  Hopefully I'll get a look through one at some point.

Thanks for sharing the photos.  It's amazing what equipment people have had and currently have.  It blows my mind that a human (rather than an observatory) would own a scope as large as that 6".  I like seeing the kit people have worked through and how it grows and develops with them.  There's something very organic and natural about it.