Dob Dilemma....

[spacedobsonian]

I was searching for a good portable dob and I found 2, but can't decide which one to take..... It's pretty much a dob dilemma 

First contender:

Skywatcher Heritage 100mm dob:

https://www.firstlightoptics.com/heritage/skywatcher-heritage-100p-tabletop-dobsonian.html

Second contender:

Ursa Major 102mm dob:

https://www.firstlightoptics.com/beginner-telescopes/ursa-major-102mm-tabletop-dobsonian-telescope.html

Now, I can buy 3 accesories which each of these scope and they are:

Astro Essentials Plossl Eyepiece:

https://www.firstlightoptics.com/astro-essentials-eyepieces/astro-essentials-super-plossl-eyepiece.html

Astro Essentials 2x Barlow:

https://www.firstlightoptics.com/barlow-eyepieces/astro-essentials-125-2x-barlow-with-t-thread.html

Skywatcher Planetary eyepiece:

https://www.firstlightoptics.com/skywatcher-eyepieces/skywatcher-uwa-planetary-eyepieces.html

Now, the real dilemma is that the Ursa Major dob (will refer to this dob as UM dob) has a spherical mirror BUT it has these great Astro Essentials Plossls 

The Skywatcher dob (will refer to it as SW dob) has a parabolic mirror BUT it has these not-so-great eyepieces. 

From the price point the SW dob is better than the UM dob, so which one do I choose??

(P.S I am going to do a bit of serious work with the dob that I will buy, UM or SW, for eg. The Moon, Jupiter, Saturn, Orion nebula and Andromeda Galaxy AND I know that small dobs aren't good for deep space work and planetary work)

(P.P.S My price budget is 200£)

Edited January 2, 2023 by spacedobsonian

[fwm891]

Personaly I'd forget the accessories to start with go for SW 130 https://www.firstlightoptics.com/dobsonians/skywatcher-heritage-130p-flextube.html

and a £4 collimation cap (still under your budget). Don't forget the s/h market you can probably pick up a 150 sized dob within your budget. Then add eyepieces etc later when you have a better idea about what you NEED.

[spacedobsonian]

Just now, fwm891 said:

Personaly I'd forget the accessories to start with go for SW 130 https://www.firstlightoptics.com/dobsonians/skywatcher-heritage-130p-flextube.html

and a £4 collimation cap (still under your budget). Don't forget the s/h market you can probably pick up a 150 sized dob within your budget. Then add eyepieces etc later when you have a better idea about what you NEED.

I was originally going to go with the SW 130 but I read that the mount is really sloppy and etc, etc

Here's a review:

"I can complain a bit about the focuser. I needed to put some Teflon tape on the threads since there was too much slop in the movement. The tape made it stiffer and you can keep putting on more layers of tape to make it however stiff you like (and remove it easily too)"

"Now the only major complaint I have: the secondary mirror. First of all, the way it attaches to the tube is a bit finicky and it came very loose so that the secondary mirror rotated way too easily. This needed to be tightened with a small pair of pliers (there is a locking nut next to where the metal rod attaches to the inside of the tube). In a quality control issue, my secondary came installed rotated by 180 degrees from the correct orientation."

"I realised that the secondary mirror that came with the telescope was quite a bit oversized. The specs on the SkyWatcher website say that the secondary is 34.5mm. In fact, the one I got was 40mm (minor axis diameter). This represents a 31% central obstruction, which is quite high, even for a fast Newtonian (the secondary mirror gets smaller as the F number increases). In fact, the maximum size of the secondary mirror holder is 35mm in diameter and a quick calculation shows that for most objects (such a looking at the moon), a 30mm mirror is large enough. So I ordered a new 35mm diagonal mirror from Orion Optics UK and with the "Picture Hanging Strips" it was then very easy to swap the secondary mirror."

All of the above paragraphs are from a single review.

[Mandy D]

I totally agree with @fwm891. I picked up my 200P Dob for £200. If you can transport and handle a scope of this size, it will certainly perform better on the deep sky and works well on the Moon, too. For the planets, you can image Jupiter and Saturn, but would be better adding the Barlow. I've had some nice views of planets in my 250PX and these should show up nicely in the 200P.

I agree that the eyepieces included with these scopes are not great, but the 25 mm works quite well, but I don't like the 10 mm. Get the scope first and use whatever eyepieces it comes with. You can always get better ones later. Be warned that a second-hand reflector may require collimating before you can use it, but that is something you need to learn anyway.

[spacedobsonian]

2 minutes ago, Mandy D said:

I totally agree with @fwm891. I picked up my 200P Dob for £200. If you can transport and handle a scope of this size, it will certainly perform better on the deep sky and works well on the Moon, too. For the planets, you can image Jupiter and Saturn, but would be better adding the Barlow. I've had some nice views of planets in my 250PX and these should show up nicely in the 200P.

I agree that the eyepieces included with these scopes are not great, but the 25 mm works quite well, but I don't like the 10 mm. Get the scope first and use whatever eyepieces it comes with. You can always get better ones later. Be warned that a second-hand reflector may require collimating before you can use it, but that is something you need to learn anyway.

Hey @Mandy D please check my reply to @fwm891

Edited January 2, 2023 by spacedobsonian

[PeterStudz]

I have a Skywatcher skyliner 1145p. It has the same focuser as the Skywatcher Heritage 100mm Dob. And I needed Teflon tape on that to remove slop when focusing. 

I don’t have any experience with the SW 130 Dob, but it’s popular, well regarded and I’ve never heard anyone complain about the mount. 

[Mandy D]

3 minutes ago, spacedobsonian said:

Hey @Mandy D please check my reply to @fwm891

Yes, I read that. I have to say that the secondary mirror is very well supported in the 200P and 250PX and I've never had to touch it on either scope. It's sizing on these two scopes has never presented an issue to me. I also have and iOptron RC6 which is 50% obstructed and I find it OK, both visually and photographically, although you do lose some contrast, which is easy to regain in GIMP on images.

Likewise, I've had no issues with the focusers on either of my Dobs, although it might be nice to have a fine movement control on them like the RC6 has.

[fwm891]

13 minutes ago, spacedobsonian said:

I was originally going to go with the SW 130 but I read that the mount is really sloppy and etc, etc

Here's a review:

"I can complain a bit about the focuser. I needed to put some Teflon tape on the threads since there was too much slop in the movement. The tape made it stiffer and you can keep putting on more layers of tape to make it however stiff you like (and remove it easily too)"

"Now the only major complaint I have: the secondary mirror. First of all, the way it attaches to the tube is a bit finicky and it came very loose so that the secondary mirror rotated way too easily. This needed to be tightened with a small pair of pliers (there is a locking nut next to where the metal rod attaches to the inside of the tube). In a quality control issue, my secondary came installed rotated by 180 degrees from the correct orientation."

"I realised that the secondary mirror that came with the telescope was quite a bit oversized. The specs on the SkyWatcher website say that the secondary is 34.5mm. In fact, the one I got was 40mm (minor axis diameter). This represents a 31% central obstruction, which is quite high, even for a fast Newtonian (the secondary mirror gets smaller as the F number increases). In fact, the maximum size of the secondary mirror holder is 35mm in diameter and a quick calculation shows that for most objects (such a looking at the moon), a 30mm mirror is large enough. So I ordered a new 35mm diagonal mirror from Orion Optics UK and with the "Picture Hanging Strips" it was then very easy to swap the secondary mirror."

All of the above paragraphs are from a single review.

I take it you just looked at the poorer review and ignored the good ones. Pretty much all new scopes will require some adjustments. They're built to a price so final adjustments may only be mediocre at best.

Take note of Mandy's reply a s/h 150 or 200mm with stock eyepieces will be much better than a 100mm with slightly better eyepieces.

Edited January 2, 2023 by fwm891

[Mandy D]

3 minutes ago, PeterStudz said:

I have a Skywatcher skyliner 1145p. It has the same focuser as the Skywatcher Heritage 100mm Dob. And I needed Teflon tape on that to remove slop when focusing. 

I don’t have any experience with the SW 130 Dob, but it’s popular, well regarded and I’ve never heard anyone complain about the mount. 

You have a Skywatcher 200P with a fabulous homemade base, if I recall corectly. Perhaps you could add your opinion on that scope to what @fwm891 and I have said.

[fwm891]

Just seen this in SGL's classifieds:

Also this on UKABS - sure you can haggle them down a touch... https://www.astrobuysell.com/uk/propview.php?view=194307

 

Edited January 2, 2023 by fwm891
Text added

[PeterStudz]

11 minutes ago, Mandy D said:

You have a Skywatcher 200P with a fabulous homemade base, if I recall corectly. Perhaps you could add your opinion on that scope to what @fwm891 and I have said.

Yes, and thank you. I got it for free in April 2021 from a member on here. It came without a base and had simply been neglected. Now, at that time I’d only been in the hobby for 4 months so was very much a beginner. But it is well put together  and super easy to work on, take apart, and put back together again. I’ve attached some pictures.

The 200p has been and still is fantastic and I’ve had so much fun with it. My daughter too who also enjoys astronomy. In fact I’m just about to put it out now for some views of Mars, Jupiter, the moon and whatever else I can see. 

[Peter Drew]

Don't forget that the OP is located in India which makes some of the advice challenging.     🙂

[Guest]

So here is a question.  What kind of vehicle are you going to be transported this in or on.  For me I can transport my 16 on a whim, but i have a fullsized truck which makes it simple.  So the size of the scope will need to be in direct proportion to your vehicle.  So tell us.... What kind of vehicle will you be using 

[spacedobsonian]

15 hours ago, fwm891 said:

I take it you just looked at the poorer review and ignored the good ones. Pretty much all new scopes will require some adjustments. They're built to a price so final adjustments may only be mediocre at best.

Take note of Mandy's reply a s/h 150 or 200mm with stock eyepieces will be much better than a 100mm with slightly better eyepieces.

I actually read all reviews but I just pointed the ones that were a bit negative! 

[spacedobsonian]

14 hours ago, PeterStudz said:

Yes, and thank you. I got it for free in April 2021 from a member on here. It came without a base and had simply been neglected. Now, at that time I’d only been in the hobby for 4 months so was very much a beginner. But it is well put together  and super easy to work on, take apart, and put back together again. I’ve attached some pictures.

The 200p has been and still is fantastic and I’ve had so much fun with it. My daughter too who also enjoys astronomy. In fact I’m just about to put it out now for some views of Mars, Jupiter, the moon and whatever else I can see. 

Pretty nice dob!  

[spacedobsonian]

10 hours ago, Mike Q said:

So here is a question.  What kind of vehicle are you going to be transported this in or on.  For me I can transport my 16 on a whim, but i have a fullsized truck which makes it simple.  So the size of the scope will need to be in direct proportion to your vehicle.  So tell us.... What kind of vehicle will you be using 

It will be transported on a car but I also want it to be very compact because it will be travelling! 

[PeterStudz]

14 minutes ago, spacedobsonian said:

It will be transported on a car but I also want it to be very compact because it will be travelling! 

Last summer I took my Skywatcher Skyhawk 1145p on an aircraft. The OTA, mount, eyepiece and accessories all fitted into a medium size hand luggage case. I even had room for a few cloths which doubled  as packing. The only thing that went into the hold was a lightweight aluminium tripod. And it would have been possible to cut the tripod down so that it also fitted into the same hand luggage case.

For travelling and with a small reflector, I prefer a tripod over a small Dob base. With a tripod there’s no need to find a table or similar in order to bring it up to eye level. Also handy as some of the time I was walking and had to setup over very rough ground with rocks. Again, a tripod is no problem here. 

Edited January 3, 2023 by PeterStudz

[Guest]

1 hour ago, spacedobsonian said:

It will be transported on a car but I also want it to be very compact because it will be travelling! 

Well whatever you get it needs to fit inside it.  For a dob you will need to consider the base