Choosing my first beginner telescope (Dobsonian vs EQ mount)

[newAstronomer]

Hello everyone!
I'm looking to buy my 1st telescope and I need your help.

So I'm looking for a telescope for up to € 300. At first I was thinking of getting a cheap 70mm but after some research on various books and forums I came to the conclusion that these are to be avoided. Should I go to 90mm achromat at 199 € (in my country), is it worth it?
What worries me most is whether I shall prefer a Dobsonian or a newtonian on an equatorial mount? The large diameter of the dobsonians is really tempting, but will I be able to track an object (eg the Moon) if it's lost after a while from the field of view? I'm worried that the AZ mount of a dobsonian will make observation of objects difficult at high magnifications. Not only that but will I be able to take photos of planets or galaxies with a dobsonian? I'm not interested in getting deep into astrophotography but I would like to have the ability to take pictures of what I see. For capturing nebulas or galaxies, do I need long exposures? Is it possible to take long exposure shots of Deep Space Objects with only few seconds of exposure (<15 seconds)?? Besides that, I'm interested in it being easy to carry and easy to set up for a beginner. What caught my attention is (at a rising price):
- DOBSONIAN TRUSS 130mm Heritage 219 € (planetarium) although I'm worried that I'll touch it (table?)
- SKYWATCHER 130/900 EQ2 € 279, will EQ2 be a sturdy-solid mount? Why aren't there enough telescopes with better supports? A question, as the number goes up (EQ3, EQ4, EQ5) does that mean it's getting better?
- SKYWATCHER DOBSONIAN 6 ″ 349 €
- SKYWATCHER DOBSONIAN 8" second-hand priced 250-300€ (if I found one) Also, is the 8" way more difficult to move? I see that it is at least 10 kg heavier than the 6" dob.

[jonathan]

Your options regarding photography with a Dobsonian will be very limited compared to an EQ mount, unless you spend the best part of £2,000 on a goto (or install your own tracking motors), tracking on a Dob is not as easy as tracking with an EQ but it is possible.  You should be able to get photos of the brighter planets and the moon with a Dob, it will be almost the same as having your camera on a standard camera tripod, except at higher magnifications you will get more movement through the eyepiece / frame so you'll need faster shutter speeds.

Manually following an object is a two-step process with any Alt-Az mount, the Dob is no exception, as you have to nudge in two axes rather than just the one with an EQ.

EQ mount numbers refer to the size and weight of the mount, and thus it's carrying capacity.  The larger the mount, the steadier it will be.  An EQ2 is pretty weedy and you realistically wouldn't want to put more than an 80mm refractor or a 130mm reflector on one, for anything bigger you'd want EQ3 or better yet EQ4 (Celestron do a good one, Omni CG-4, which has 1.75" steel tubular legs - much better than the square aluminium legs).  Larger EQ mounts (e.g. EQ5 Pro) will also have better gears and upgrade options for tracking and Goto, tracking can be added to EQ3-2 / Omni CG-4 as well in one or both axes (usually just one axis is required for normal tracking, RA or Right Ascension).

If portability, ease of carrying and use, and versatility are your main wants then I'd say forget the larger dobsonians as a starter scope, they are big and heavy and may end up not getting much use because they're a chore to get out (not to mention store).  I think a 6" dob is going to be much more manageable, or something like the Skywatcher 150P (a 6" reflector) on EQ3-2 (I use mine on a Celestron Omni CG-4 mount, which is a bit more stable).  The 150mm reflectors (whether EQ or Dob) are very good for a starter scope, especially if you can stretch your budget to a couple of high quality eyepieces to really make the best use of the optics, the supplied eyepieces (usually 10mm and 20mm) will get you going and be fine for some targets, but once you spend £150 on a single eyepiece you will really see what the scope is capable of.  I would recommend something around the 12 - 14mm range and a wide field eyepiece (82 degrees if possible), I have a really nice Explorer Scientific 14mm which has an 82 degree field of view, possibly my favourite eyepiece at the moment.

Don't discount the 70mm refractor completely, there are some excellent ones out there, you just need to stick to the popular astronomy brands and steer well clear of the 'never-heard-of-it' supermarket brands.  Good brands to look out for include Celestron, Skywatcher, Meade; there are a few others that tend to be more specialist and thus more expensive.  Have a look at the Celestron 70mm Travel Scope as a good light-weight refractor, I have this one (picked it up complete for £20 second hand, hardly used) and it's surprising how clear and crisp the views can be; granted, you can't see the faint fuzzies very well and most clusters are just grey blobs (except for open clusters, they can look great), but it works brilliantly for bright objects, the moon, Orion Nebula, and being small and light it's one that you can literally throw on a good camera tripod and be out there observing in two minutes, almost zero setup time!  It will attach to an EQ mount as well if you want tracking, being very light it will sit on anything from EQ2 upwards (EQ1 is a bit of a waste of time IMO).  I usually use mine on my Omni CG-4, it can also be used very effectively as a daytime spotting scope as it comes with a 45 degree erecting diagonal (I think as well as the 90 degree non-erecting one).

Hope that helps!

Edited May 2, 2020 by jonathan

[newAstronomer]

Thank you for taking the time to help me choose a telescope.

Besides astrophotography, as I understand it, I should prefer a telescope with an EQ mount because it is easier to track an object? Is a dobsonian going to be an inconvienience if I want to observe (NOT photograph) something for quite some time?

Is the SW 130/900 EQ2 a bad choice? The specs of this one say that it spherical, it that going to be a problem for observations? Unfortunately, that's the only one sold at the only astronomy store in my country.  Unfortunately, buying a dobsonian 6" and placing it on an EQ mount is not an option to me due to the high cost. Perhaps I shall try to find from another store a SW 150 on an EQ3 mount as you suggested?

Aside what I plan to do (astrophotography or not), what kind of telescope would you suggest to me,  in terms as to which is easier to use, a dobsonian or a reflector on an EQ mount? Will I be able to manage to correctly align the mount with Polaris? I hesitate choosing an EQ mount due to difficulty in aligning it.

[Louis D]

You can always build an equatorial platform as described in this thread to add tracking to any Dob for an hour at a time.  The OP of that thread has a nice pdf describing his build.

[Cosmic Geoff]

Dobsonians have their fans, but as you are already aware, you have to do all the finding and tracking yourself.  People have taken photos with them, but if you want to image you should buy something that is suitable for imaging.

As a beginner, you should avoid EQ mounts unless you particularly value the ability to track an object using a RA motor.   Otherwise, an equatorial only comes into its own for deep space astrophotography (an expensive exercise) where it is essential to avoid field rotation on long exposures.

Some people like small refractors, but you should be prepared to pay a bit more for a good one.   I have had two, a department store one which was very cheap but the objective lens was no good, and a vintage 70mm Ross which does everything a 70mm scope should, but is very long and heavy and requires a substantial mount.  The modern ED and APO refractors are much shorter.

Like many of us, you will probably end up owning more than one scope, so pick something and get started.🙂

Edited May 2, 2020 by Cosmic Geoff

[DaveL59]

15 hours ago, newAstronomer said:

 

Is the SW 130/900 EQ2 a bad choice?

I've one of these, can't say if its spherical as I bought it used and there's nothing to indicate its a P so probably it is. It's a competent scope for visual tho the long tube will catch the breeze and wobble. The mount is an EQ2 which manages the scope fine but is at its limit in terms of load and isn't regarded as a mount suited to photography. The RA (clockwork drive) motor add-on works and is reasonably quiet, batteries last ages and helps the scope keep tracking the object you've selected. Means you can just chill and enjoy the view and not have to fiddle with adjustments. The bonus part of that is... as you adjust the slo-mo controls you set the tube wobbling for a few seconds and need to wait for it to settle again to get a good view.

The focuser can take a camera with adaptors I believe, I don't have an SLR to confirm, but I'm not sure if there is enough focuser in-travel to get focus, possibly but I don't know. You could grab pics via the eyepiece though with phone or compact camera, at least of the moon and planets. With better eyepieces the scope performs nicely I find, so isn't a bad one, but given you'd want to expand later to AP then perhaps a 150P on EQ3-2 would be better, others who have that scope might advise better on its merits.

I wouldn't say as a beginner to avoid an EQ mount tho, sure and ALT-AZ is easier to get started on as its obvious where the scope will move to if you do X or Y. But the EQ isn't so hard, just play with it in daylight to see how its operating and watch tutorial vids so you've got your head around it before you try in total darkness and then struggle to get things pointed where you want  

[Ricochet]

21 hours ago, newAstronomer said:

but will I be able to track an object (eg the Moon) if it's lost after a while from the field of view? I'm worried that the AZ mount of a dobsonian will make observation of objects difficult at high magnifications

After a while it becomes second nature to nudge the telescope to keep things in view. If you walk away and come back later you will have to start over so in that situation an EQ mount is a bit easier, if you have semi accurately polar aligned it. Generally speaking, everything moves left to right, with some up or down movement, depending on where it is in the sky (but it appears as right to left, due to being flipped by the mirrors).

21 hours ago, newAstronomer said:

will I be able to take photos of planets or galaxies with a dobsonian?

Planets probably, because you take a very quick video and combine video frames to make a single image. Galaxies no, as those require long exposures and a mount capable of accurately tracking the apparent movement across the sky. None of the mounts supplied with your suggested telescopes fit that bill, so I would completely ignore the idea of DSO photography when choosing a scope. Choosing an eq2 mounted scope with the misguided belief that you can use it for astrophotography will surely lead to disappointment. 

21 hours ago, newAstronomer said:

A question, as the number goes up (EQ3, EQ4, EQ5) does that mean it's getting better?

Generally, yes. The standard minimum suggested mount for starting astrophotography is the HEQ5, to give you an idea of costs.

21 hours ago, newAstronomer said:

Also, is the 8" way more difficult to move? I see that it is at least 10 kg heavier than the 6" dob.

Heavier will naturally be more difficult, but I find that the 8" is at the limit of what I can carry for a short distance all as one unit. You can always carry the base and telescope separately if you find it is too much weight as one unit.

[newAstronomer]

11 hours ago, Ricochet said:

Planets probably, because you take a very quick video and combine video frames to make a single image. Galaxies no, as those require long exposures and a mount capable of accurately tracking the apparent movement across the sky. None of the mounts supplied with your suggested telescopes fit that bill, so I would completely ignore the idea of DSO photography when choosing a scope. Choosing an eq2 mounted scope with the misguided belief that you can use it for astrophotography will surely lead to disappointment.

So even a Skywatcher Telescope N 150/750 Explorer BD EQ3-2 would be out of the question for astrophotography?

The thing is that right now with my binoculars I spend more time on trying to get a picture rather than observing (The Moon, stars). I'm worried that if I buy a dobsonian I'll regret that I can't even take a picture of a nebula or a star cluster or a galaxy or a double star. Not only that, but I might even get frustrated having to keep adjust the AZ mount.  On the other hand, is there any chance I'll find the EQ mount impossible to align and use? Perhaps my ignorance of how exactly dobsonians or eq mounts work make be have doubts. I have read books (Backyard Astronomer's Guide) and searched various astronomy forums in the past but I didn't understand everything. Perhaps I shall give my book another pass.

[DaveL59]

have a search on youtube for videos on how the EQ mount works, which should give you some idea.

To get good tracking then ideally you need to level and polar align if just using the RA motor. GoTo types you could use a guide camera to instruct the mount either via the ST4 connection or via a PC using appropriate software, but you still want the polar alignment reasonably accurate or you'll get shift in the image on longer exposures. Personally (am visual not photo) I prefer EQ as I only need RA adjustment once on a target to follow it, where ALT-AZ or dob you have to move in both axes and unless you have a wedge then you'd still get image rotation I believe.

[Cosmic Geoff]

10 hours ago, newAstronomer said:

21 hours ago, Ricochet said:

 

So even a Skywatcher Telescope N 150/750 Explorer BD EQ3-2 would be out of the question for astrophotography?

Neither the telescope nor the mount (without drives) is particularly suited to astrophotography.  Trying to do astrophotography with inadequate kit will merely lead to disappointment. You need to decide priorities. Either aim for a visual outfit for 300 euros, or  choose a lightweight GoTo mount for 300 euros and mount a DSLR camera directly on it for some widefield imaging.  Have a look in the Imaging sections of this forum and see what kit the successful imagers are actually using.