Visual astronomy, dob vs newt equipment query.

[shan (Shannon)]

Hi,

I have two equipment-related questions for visual astronomy purposes.

1. What are the main differences when looking through a Sky-Watcher Classic 200P Dobsonian vs Sky-Watcher 200 Black Diamond f/5 Newtonian?

2. Can a Sky-Watched Quattro 200 f/4 Newtonian also be used for visual astronomy?

I would love to hear your thoughts and recommendations,

Thanks, Shan

[Startrek (Martin)]

Welcome to IIS

Quick Answers

1. No difference visually as both telescopes have similar aperture and focal length. I think from memory the 8” Dob has an f6 focal ratio thus slightly narrower FOV than the f5 OTA
For visual astronomy as a beginner , the Dob is probably the better choice as it’s primarily designed for observing and easier to set up. A drum stool is a handy accessory to use with the Dob as you can adjust your sitting height to suit the position of the eye piece. The f5 OTA requires a mount ( EQ or AZ ) , hand operated ( manual ) or a Goto ( automatic) with telescope control.

2. For visual observing, steer away from f4 Newtonians , they are designed for imaging with their fast optics, and are more difficult to collimate. They are an advanced Newtonian and obviously more expensive.
They “can” be used for visual observing with an appropriate coma corrector but why use an imaging Newtonian as a visual telescope , doesn’t make sense unless you want to venture into imaging later on.

Cheers
Martin

[EpickCrom (Joe)]

Hi Shan and welcome to IIS!

For visual observing, I highly recommend getting a dobsonian mount. It is the easiest and most intuitive mount for a reflector. You just point and observe! As Martin has said, f4 is a fast scope which will be more sensitive to precise collimation and will need a coma corrector for visual ( the faster the focal ratio the more coma you see)

There will be no difference visually between the f5 Sky Watcher Classic and Black Diamond as they are the same focal ratio. Good luck on your visual journey and feel free to ask as many questions as you like!

Cheers
Joe

[shan (Shannon)]

Hi Martin and Joe,

I appreciate your reply and all the info you both provided.

With reference to Martin’s point number 2, during my research so far I’m aware there’s not a 100% perfect telescope for both visual and photography but I was thinking of buying something like a SW Quattro 200 f/4 newt that allows me to use as a visual scope for now and purchase a camera at a later date for basic EAA and photography. Would this scope be suited for this purpose or am I better off going with something like the SW 200 f/5 newt.

[Startrek (Martin)]

Originally Posted by shan

Hi Martin and Joe,

I appreciate your reply and all the info you both provided.

With reference to Martin’s point number 2, during my research so far I’m aware there’s not a 100% perfect telescope for both visual and photography but I was thinking of buying something like a SW Quattro 200 f/4 newt that allows me to use as a visual scope for now and purchase a camera at a later date for basic EAA and photography. Would this scope be suited for this purpose or am I better off going with something like the SW 200 f/5 newt.

Shan,
As a beginner astrophotographer ( even EAA ) I’d strongly avoid f4 Newts until you achieve some skill set and advance to intermediate level in a few years time.
I’ve been at it 6 years now and all my carbon fibre Newts are f5 , they do a superb job , great all rounders !!
Just remember in EAA and AP , a suitable mount is first consideration followed by your telescope ( not in reverse)
A SW EQ6-R pro mount ( recommended max payload 15kg ) would suit the SW 200 f5 Newt for both EAA and Deep Space AP
There are many other brands and models to choose from but SW gear is a great first step in regard to cost , quality , local support and availability

Hope others chime in to give you more advice and recommendations

Cheers
Martin

[shan (Shannon)]

Great advice. Thanks Martin

[gaseous (Patrick)]

Welcome Shan,


as others have said, F4 is getting pretty precarious for visual use. My 8" F/6 dob works fine without a coma corrector, whereas my 20" F/4 is virtually unusable without a cc. I can't speak from an imaging perspective, but as you've alluded to, there probably isn't a scope+mount combo which is ideal for both beginner-to-advanced visual use and AP down the track. AP is for suckers anyway.... (just jokes!)

[Bodon (Steve)]

Hi Shan
Mate, I have a SW10" f/5, which I purchased as my first scope two years ago. I have it on an SW AZEQ6 and put it in AZ mode and tracks real nice. The mount suits a reflector as I dont have to get into weird positions in AZ. EQ mode will get that focuser up a tad high etc.
I do astro with this mount but use a refractor.

As a newbie I wish I purchased the Quattro as it has a stronger focusor and shorter in length which can be used for astro where as the reflector I have the focusor cannot handle the weight of a decent camera and filter wheel etc.
Something to think about if you decide to use the reflector with a camera.


I will use the reflector for astro but a decent focusor is quite pricey.