Sky-Watcher 200P

[malgpz900]

Pros and cons of EQ over Dobsonian mounts.

TIA

Malcolm.

[malc-c]

I'm sure if you searched or browsed through the forum you'll find similar posts discussing the virtues of either

[Louis D]

• EQs track, Dobs can too with either an EQ platform or alt-az motors and computerized control.
• EQs weigh quite a bit more than an equivalent alt-az mount due to the massive counterweights for a 200P.
• EQs are insanely top heavy once assembled, so next to impossible to safely move around the yard to dodge obstructions unless mounted on a dolly/wheeley bars/etc.
• Dobs are bottom heavy and quite stable.  They can be moved around assembled by penguin walking them while hugging them close to the body.
• The focuser rotates into awkward orientations on an EQ for Newts if lacking rotating rings.  It's stays in pretty much the same orientation for Dobs.
• You need a really beefy EQ mount to handle a 200P that can cost well more than the OTA.

[bosun21]

If you are thinking about astrophotography then it’s got to be the EQ mount. This will accurately track and be guided in both axis. This won’t be cheap .The  dobsonian mount can be a go to, a push to, or a manual. In the end it’s up to you what you want to do with your telescope, and how you intend to use it.

[Louis D]

8 minutes ago, bosun21 said:

If you are thinking about astrophotography then it’s got to be the EQ mount.

You can definitely do DSO astrophotography with a dual axis equatorial platform as well.  In fact, if you're using a 12" or larger Newt, I would recommend to go that route over an enormous GEM EQ.

[bosun21]

1 minute ago, Louis D said:

You can definitely do DSO astrophotography with a dual axis equatorial platform as well.  In fact, if you're using a 12" or larger Newt, I would recommend to go that route over an enormous GEM EQ.

It’s a matter of choice i suppose. In sizes over 12” I am in agreement with you. The dual axis equatorial platforms are pretty costly as well, although not as expensive as a GEM EQ.

[Spile]

The case for the Dobsonian https://astro.catshill.com/why-did-i-choose-a-dobsonian/

[Astro_Dad]

Obviously you can do basic astrophotography (to a point) with even a manual Alt Az mount depending on the target you want to capture. Have a look at @Spile’s blog and even my own examples on this forum! 

[malgpz900]

21 hours ago, malc-c said:

I'm sure if you searched or browsed through the forum you'll find similar posts discussing the virtues of either

Yeah, tried that. Thanks for your suggestion.

[Moonshane]

The problem is actually that the answer to your question is that 'it depends'. If for example you are looking solely at imaging, then a large GEM or similar and a smaller newtonian (i.e. smaller than your 200p) would be a good starting point (although even that depends on what you wish to image).

If you are looking at visual astronomy only then a manual dobsonian would be far more cost effective for a larger newtonian (i.e. such as your 200p) although you would presumably have to make or somehow source a dobsonian mount which might be tricky (relatively easy if OK at DIY though ( e.g. the link below). The eyepiece of a larger newtonian would be very high up on most suitable GEMs and you'd possibly need a step ladder for observing at the zenith.

That said, it all depends upon budget and available space to e.g. store a couple of options. It's often cheaper to buy a larger dob and a smaller refractor with a smaller GEM than buy a huge GEM to 'make it work' with the gear you have. As I say 'it depends' 🙂

 

[malc-c]

1 hour ago, malgpz900 said:

Yeah, tried that. Thanks for your suggestion.

Your question is too open ended.  If all you want to do is visual observing then a Dob will fit that bill just fine,  It's as basic as you can get, a tube set into a yoke on a rotating base.  The main advantage over any other form of mount is for a given budget you get more aperture compared to any other scope.  If you want to start imaging, then you will be limited to the options available, possibly just taking a video of the moon and stacking the result. The reason is that they are non equatorial and lack the ability to track correctly, by that I mean they suffer from field rotation.

EQ mounted scopes tend to be more costly, mainly because the mount forms a good 50% of the cost.  Their main advantage is that they can track a target without any field rotation, making an EQ scope more suited to imaging.  The draw back is that to get something to take the weight of a scope of similar size to a dob the mount needs to be sturdy which tends to lean towards mounts that are heavy and expensive.  But an expensive mount will have the precision if you want to do some serious imaging.

You can modify dobs to function as an EQ mount using raised platforms etc.  But this can lead to other issues as by design they are not meant to function in that way.  Equally you can use an EQ as an ALT/AZ mount, but then if the mount is driven the software won't function correctly as it's not expecting the mount to be used this way.  There are AZ/ALT/EQ mode scopes that overcome this with dual mode software, but again, these mounts are more costly.

Also there is the topic of mobility.  An 8" dob is far easier to transport to a remote site compared to a 200P on and EQ6, especially if you have a 200m trek from the car park.  But then for a similar budget you could have a 12" or 14" dobsonian which can be less portable, and require several trips to transport the scope in sections.  As I said, the topic is too open and really needs fine tuning to state the advantages / disadvantage between two or three different models of scopes.