Helical focuser with phone adapter?

[Elio_C]

Hi stargazers,

Recently I have been saving up for a new scope, the Skywatcher 150p Dobsonian: 

https://skywatcheraustralia.com.au/product/6-tabletop-dobsonian/

It's had some great reviews, and I'm very excited as it is quite an upgrade. 

In the meantime though, I have been doing some smartphone astrophotography with my current scope, and I've really enjoyed getting the photos so I can show people what its like in the scope and so I can appreciate the sky all the time. Ideally it would be great if I could get a phone adapter for my new scope so I wouldn't have to hold my hand shakily up to the eyepiece and get dodgy quality videos of a few seconds of seeing my target. However, the new scope has a helical focuser, which means I would have to rotate the entire eyepiece shaft to focus the scope, which would be a massive pain if I had a phone adapter on the scope.

Is there any solution to this dilemma? Should I look at a different scope or a different adapter? Or is there a way of getting around this? 

 

Thanks everyone, 

Elio. 

[Alan64]

Yes, that kit and the smaller "Heritage" 130mm f/5 are collapsibles, and with a helical focusser.  In that you're wanting to take pictures, you may prefer a 150mm f/8 Newtonian-Dobson, and with a conventional, metal 2"/1.25" focusser...

https://skywatcheraustralia.com.au/product/6-classic-dobsonian/

If you can find this 150mm f/5 Newtonian-Dobson kit there in Australia, it has a solid tube and a traditional(albeit plastic) 1.25" rack-and-pinion focusser...

https://www.amazon.com.au/Orion-10016-StarBlast-Reflector-Telescope/dp/B00463ZK3O

If you wouldn't mind bumping the aperture down a bit, yet with no collimation worries...

https://skywatcheraustralia.com.au/product/90-eq2-refractor/

Edited October 20, 2020 by Alan64

[Stu]

Hi @Elio_C

The Heritage 150p is a great scope; I have one myself and it performs very well. The focuser is the weak point of the scope really. It does a perfectly adequate job with eyepieces, but my personal view is that it probably isn’t up to holding and eyepiece, phone holder and phone. It does have some flex in it and I’m just not sure this would work very well.

Stu

[Elio_C]

10 minutes ago, Stu said:

Hi @Elio_C

The Heritage 150p is a great scope; I have one myself and it performs very well. The focuser is the weak point of the scope really. It does a perfectly adequate job with eyepieces, but my personal view is that it probably isn’t up to holding and eyepiece, phone holder and phone. It does have some flex in it and I’m just not sure this would work very well.

Stu

 

2 hours ago, Alan64 said:

Yes, that kit and the smaller "Heritage" 130mm f/5 are collapsibles, and with a helical focusser.  In that you're wanting to take pictures, you may prefer a 150mm f/8 Newtonian-Dobson, and with a conventional, metal 2"/1.25" focusser...

https://skywatcheraustralia.com.au/product/6-classic-dobsonian/

If you can find this 150mm f/5 Newtonian-Dobson kit there in Australia, it has a solid tube and a traditional(albeit plastic) 1.25" rack-and-pinion focusser...

https://www.amazon.com.au/Orion-10016-StarBlast-Reflector-Telescope/dp/B00463ZK3O

If you wouldn't mind bumping the aperture down a bit, yet with no collimation worries...

https://skywatcheraustralia.com.au/product/90-eq2-refractor/

Thanks very much for the responses, they've been really helpful, I'll get back to this thread if I have any other questions. 

[Elio_C]

I've worked out that the Orion Starblast 6 is unavailable in Australia, but I have found a Saxon (skywatcher) deepsky 8" dobsonian for quite a bargain second hand and local. It is usually valued at $730 AUD, but this one is at $550 AUD. It is quite out of my budget but is the price worth it? 

To be honest, unless this is an unmissable bargain, I'm keen to keep it to a smaller set up so later on I might turn it into an OTA on a mount. 

Also, that is quite a significant cash splash for a scope that might be too big for what I'm wanting to use it for! 

So I'm thinking, if not the Saxon then maybe I'll just stick to the heritage 150p and hold my phone up to the eyepiece when I want to take a photo or video... 

Or maybe the 6" saxon deepsky is the way to go? I'm just worried with its focal length that it might be too big. I've never seen it next to a person for comparison. 

[Alan64]

7 hours ago, Elio_C said:

I've worked out that the Orion Starblast 6 is unavailable in Australia, but I have found a Saxon (skywatcher) deepsky 8" dobsonian for quite a bargain second hand and local. It is usually valued at $730 AUD, but this one is at $550 AUD. It is quite out of my budget but is the price worth it? 

To be honest, unless this is an unmissable bargain, I'm keen to keep it to a smaller set up so later on I might turn it into an OTA on a mount. 

Also, that is quite a significant cash splash for a scope that might be too big for what I'm wanting to use it for! 

So I'm thinking, if not the Saxon then maybe I'll just stick to the heritage 150p and hold my phone up to the eyepiece when I want to take a photo or video... 

Or maybe the 6" saxon deepsky is the way to go? I'm just worried with its focal length that it might be too big. I've never seen it next to a person for comparison. 

Both the 6"f/8 and 8" f/6 Newtonian-Dobsons have the same focal-length: 1200mm, and great for medium-low, medium, and high magnifications; not so much for low-power, wide-field views.  But then, a telescope, in the first place, is for seeing faraway objects up close, and closer still if the collimation is spot-on.  Else, you'd use a pair of binoculars.  It just so happens that I have that Orion 6" f/5 kit...

However, notice what I did.  I couldn't stand the original Dobson alt-azimuth mount, so I moved the telescope over to a tripod-type alt-azimuth, and the experience was worlds better.  A 6" f/5 Newtonian has it all, almost: a shorter tube, an appreciable aperture, and the ability to observe most everything in the night sky, from about 20x(binocular-like), up to 200x and beyond.  It's quite the all-rounder.  Although a 6" f/5 Newtonian is more difficult to collimate compared to a 6" f/8 Newtonian-Dobson, but not as badly as that might seem to imply.  In addition, the secondary-obstruction is larger at f/5 versus f/8.  Such will reduce sharpness, for it's an obstruction, like a cataract of the human eye.  That of an f/8 is smaller, and negligible.

If you're curious, you can peruse the finer GSO 6" f/5 OTA, and the same tripod-type alt-azimuth that I have, here...

http://www.andrewscom.com.au/site-content-section-10-guansheng.htm#accessories

...decisions, decisions.

Edited October 21, 2020 by Alan64

[Elio_C]

11 minutes ago, Alan64 said:

Both the 6"f/8 and 8" f/6 Newtonian-Dobsons have the same focal-length: 1200mm, and great for medium-low, medium, and high magnifications; not so much for low-power, wide-field views.  But then, a telescope, in the first place, is for seeing faraway objects up close, and closer still if the collimation is spot-on.  Else, you'd use a pair of binoculars.  It just so happens that I have that Orion 6" f/5 kit...

However, notice what I did.  I couldn't stand the original Dobson alt-azimuth mount, so I moved the telescope over to a tripod-type alt-azimuth, and the experience was worlds better.  A 6" f/5 Newtonian has it all, almost: a shorter tube, an appreciable aperture, and the ability to observe most everything in the night sky, from about 20x(binocular-like), up to 200x and beyond.  It's quite the all-rounder.  Although a 6" f/5 Newtonian is more difficult to collimate compared to a 6" f/8 Newtonian-Dobson, but not as badly as that might seem to imply.  In addition, the secondary-obstruction is larger at f/5 versus f/8.  Such will reduce sharpness, for it's an obstruction, like a cataract of the human eye.  That of an f/8 is smaller, and negligible.

If you're curious, you can peruse the finer GSO 6" f/5 OTA, and the same tripod-type alt-azimuth that I have, here...

http://www.andrewscom.com.au/site-content-section-10-guansheng.htm#accessories

...decisions, decisions.

Wow, that's a dream set up! 

But I don't know where to go from here...    I can't find the 6" Orion for sale online anywhere, and the 8" is too large. 

So It's down to the 6 inch's: 

 

The Heritage 150p: 

Pros: affordable, lightweight, collapsable, easily adaptable to an altaz mount for in the future, and not too big. 

Cons: Just the helical focuser!!!!!

 

The 6" Skyliner (also skywatcher): 

Pros: the focal length, better f/ ratio, rack and pinion focuser. 

Cons: too big! rather pricey, and very heavy. (PS: its size may turn it into a hobby killer! 😬)

 

Decisions indeed... 

I know everyone at SGL loves to spend other people's money, so any advice would be greatly appreciated! 😁

[Alan64]

6 hours ago, Elio_C said:

Wow, that's a dream set up! 

But I don't know where to go from here...    I can't find the 6" Orion for sale online anywhere, and the 8" is too large. 

So It's down to the 6 inch's: 

 

The Heritage 150p: 

Pros: affordable, lightweight, collapsable, easily adaptable to an altaz mount for in the future, and not too big. 

Cons: Just the helical focuser!!!!!

 

The 6" Skyliner (also skywatcher): 

Pros: the focal length, better f/ ratio, rack and pinion focuser. 

Cons: too big! rather pricey, and very heavy. (PS: its size may turn it into a hobby killer! 😬)

 

Decisions indeed... 

I know everyone at SGL loves to spend other people's money, so any advice would be greatly appreciated! 😁

There is another con to the collapsibles: they tend to require collimation more often than a full tube.  I also suspect, over time, that the mechanical aspect of it being a collapsible would wear out over time, eventually making collimation very difficult if not impossible.

This, William Herschel's 6.13" f/13.7 "Dobsonian", and with which he discovered the planet Uranus...

Does a 6" f/8 seem too big and unmanageable still?  In hindsight, I would've gotten a 6" f/8 instead of that 6" f/5.  But that's just me, as I prefer telescopes with longer focal-lengths.  They perform better, optically.  A telescope can be ergonomic; easy to store, carry about, tuck away.  Or, a telescope can be an optical powerhouse, one's very own observatory.  A Maksutov-Cassegrain comes closest to encompassing both aspects, but it has its own issues...

Do you live in a city, or a suburb of same; or far enough away from either, under darker skies, a semi-rural to rural setting?

[Elio_C]

5 hours ago, Alan64 said:

There is another con to the collapsibles: they tend to require collimation more often than a full tube.  I also suspect, over time, that the mechanical aspect of it being a collapsible would wear out over time, eventually making collimation very difficult if not impossible.

This, William Herschel's 6.13" f/13.7 "Dobsonian", and with which he discovered the planet Uranus...

Does a 6" f/8 seem too big and unmanageable still?  In hindsight, I would've gotten a 6" f/8 instead of that 6" f/5.  But that's just me, as I prefer telescopes with longer focal-lengths.  They perform better, optically.  A telescope can be ergonomic; easy to store, carry about, tuck away.  Or, a telescope can be an optical powerhouse, one's very own observatory.  A Maksutov-Cassegrain comes closest to encompassing both aspects, but it has its own issues...

Do you live in a city, or a suburb of same; or far enough away from either, under darker skies, a semi-rural to rural setting?

Thanks for this insight, I live in the suburbs with bortle 6 skies but have a holiday house to escape to over summer with beautiful bortle 3 skies. Unfortunately I think the lack of portability of the f/8 will cause a problem when moving it over there in a car almost already full with other peoples bags and food. It may also cause a problem when moving it to an ideal viewing location. 

[Alan64]

1 hour ago, Elio_C said:

Thanks for this insight, I live in the suburbs with bortle 6 skies but have a holiday house to escape to over summer with beautiful bortle 3 skies. Unfortunately I think the lack of portability of the f/8 will cause a problem when moving it over there in a car almost already full with other peoples bags and food. It may also cause a problem when moving it to an ideal viewing location. 

I understand, hence sacrifices to be made.  Bortle-3 skies sound very nice; very nice indeed.  I have Bortle-4 to -5 here at my home.

[Elio_C]

On 20/10/2020 at 18:07, Stu said:

Hi @Elio_C

The Heritage 150p is a great scope; I have one myself and it performs very well. The focuser is the weak point of the scope really. It does a perfectly adequate job with eyepieces, but my personal view is that it probably isn’t up to holding and eyepiece, phone holder and phone. It does have some flex in it and I’m just not sure this would work very well.

Stu

Hi @Stu,

Sorry for the late post on this thread, but I just wanted to clarify if you're sure of this? 

I know that a member of this forum made a couple of great videos on the Heritage 150p, and in one he tested whether the focuser could handle heavier eyepieces. 
The conclusion ended up being that it could handle most heavier eyepieces, with a bit of wobble. 

Here's the video: 

I'm really keen to be able to take pictures through the new scope, so I would be able to share the great sights I see. 
Is the Heritage 150 simply not up to that task? Should I look for a different scope within my price range? 
I really hope that there's a solution to this dilemma, as I would hate to sacrifice aperture, portability, affordability and all the other countless benefits this scope holds for another scope. 

If it comes to it, as an alternative, I've heard great things about this scope?: 
https://www.ozscopes.com.au/skywatcher-80mm-refractor-altaz-telescope.html\

Thanks for your time, any help would be fantastic! 

Elio. 

Edited November 27, 2020 by Elio_C