What is Reddit's opinion of SVBONY Telescope Eyepiece Fully Mutil Coated 1.25 inches Telescope Accessories Set 66 Degree Ultra Wide Angle HD 9mm for Astronomy Telescope?

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The 30mm 2" wide angle is indeed a good low power widefield eyepiece. The edges of the field of view will look a bit funky with the fast F/5 focal ratio of the telescope, but I don't think it will be too bothersome.

The 9mm plossl it comes with is a fairly good general purpose focal length for that scope (good for low end planetary observing when the atmosphere is not steady, and good for most of the brighter/smaller DSOs), but the problem is the limited apparent and true field of view, and tight eye relief.

I would DEFINITELY recommend upgrading it with a 9mm "gold line" right away.

I own that 9mm and it works very well in my F/5 and and F/4.5 dobs. Can't beat its performance for the price.

If you find that the views of the planets are very crisp with the 9mm (170x), then you can go up in magnification by getting something in the 4.5mm to 6mm focal length range.

If, however, the views of the planets seem a bit blurry and hard to focus in the 9mm, then increasing magnification will not help, it will make things worse. Some nights are better than others in this regard, so I recommend being conservative and waiting until you get a night where you go "wow! That's super sharp, wish I had more magnification!" and then get an additional eyepiece.

It will also be CRUCIAL for the telescope to be thermally acclimated for viewing the planets. A large temperature difference between the mirror and ambient air will cause massive problems with the view - as bad as the atmosphere.

Also, if you live at high northern latitudes (45 degrees or higher), the planets will be low on the horizon and atmospheric turbulence will be worse, and atmospheric dispersion will be an issue.

If you're willing to push up to your budget, don't let $100 eyepieces scare you away. I had probably 10 eyepieces before I bought my first (and so far only) $100+ one. The widely recommended "Gold Line" SVBONY eyepieces are about $35 each on Amazon or $110 for the kit of 4. They're a little cheaper if you order them from one of the Chinese stores but those take longer to deliver. Those are what many people get as their first step up from kit eyepieces.

That being said, both options look like a pretty good deal - you can't go wrong.

For a 10" scope, planetary magnification typically falls between about 120x and 500x, dependent on seeing conditions.

Given your budget, I would recommend the 6mm and 9mm "gold lines":

• https://www.amazon.com/SVBONY-Telescope-Eyepiece-Accessories-Astronomy/dp/B07JHKP9D2/
• https://www.amazon.com/SVBONY-Telescope-Eyepiece-Accessories-Astronomy/dp/B07JWDFMZ4/

They aren't perfect, but they are a very good value, and will give you some magnification flexibility. The 9mm is the better of the two. The 9mm would be good for nights when the atmosphere is not very steady, while the 6mm would be good for nights when the atmosphere is more calm.

Alternatively, you could get the 8mm and 5mm Astro-Tech Paradigms:

• https://www.astronomics.com/astro-tech-8mm-1-25-paradigm-dual-ed.html
• https://www.astronomics.com/astro-tech-5mm-1-25-paradigm-dual-ed.html

Agena Astro sells the same ones for a bit more money if they are out of stock on Astronomics:

• https://agenaastro.com/agena-1-25-dual-ed-eyepiece-8mm.html
• https://agenaastro.com/agena-1-25-dual-ed-eyepiece-5mm.html

Since both would be above your budget, I would just start with the 8mm.

One of the problems is this scope used 0.965" eyepieces if I recall. If so, it will be impossible to find new eyepieces for it that will fit it. You will need to get an adapter.

The only problem with this is it that it prevents the eyepiece from sitting down in the focuser, so some eyepieces may not reach focus as the focuser may not have enough inward travel to compensate for the extra height on the focuser due to the adapter.

For eyepieces, I would get a couple from this set: https://www.amazon.com/SVBONY-Telescope-Eyepiece-Accessories-Astronomy/dp/B07JHKP9D2

1. The 20mm for low power wide angle viewing (this will give you a 1.5 degree true field of view, which given the nature of the 0.965" focuser, is about the widest you can get from this scope)
2. The 9mm for roughly 100x mag - useful for looking at the Moon in more detail
3. The 6mm (which will get you 151x, enough for planetary viewing)

If you buy the whole set, you basically get the 15mm for free. It's a good starter set that will work well in most future scope upgrades.

With a few exceptions, most eyepieces are good and generally better than the telescope itself. That is, any issues with being able to see details in objects comes down to the telescope's optics or the observing conditions. Better quality eyepieces usually have fewer aberrations, but won't necessarily show you more.

Things that can negatively impact the overall viewing experience:

1. Contrast problems from uncontrolled glare
2. Off-axis astigmatism or field curvature
3. Very narrow field of view
4. Very short eye relief

As a an example, consider the 9mm "gold line" vs the [9mm Tele Vue DeLite](https://www.highpointscientific.com/televue-9mm-delite-62-degree-1-25inch-eyepiece-ede-9].

$35 vs $269. What's the difference?

1. Both are equal in on-axis sharpness. Both show detail in the planets and the Moon equally well.
2. Can't see anything in the $269 eyepiece that you can't in the $35 eyepiece. Both show deep sky objects equally well.
3. Both have a reasonably wide field of view. $35 eyepiece has a slightly wider field of view.
4. $269 eyepiece has enough eye relief to wear glasses and has a very nice mechanical adjustable eye guard if you don't want to wear glasses.
5. $35 eyepiece has "kidney beaning" issues, which means eye placement is finicky to avoid the kidney bean shaped shadow. The $269 eyepiece doesn't have this issue.
6. $35 eyepiece has contrast issues on the Moon due to glare control problems. The 9mm eyepiece does not have this problem.
7. As stars or planets drift across the field of view in the $35 eyepiece, they start becoming distorted in shorter focal ratio telescopes. 90% of the field looks good, the last 10% starts showing distortions. In comparison, the $269 eyepiece shows perfect stars right to the field stop. You can split Jupiter's Great Red Spot in half cleanly at the field stop. The edge looks just as good as the center.

This is essentially how most comparisons between budget or mid-grade gear vs premium gear goes. Note that it's more about what you won't see in the more expensive eyepiece - namely aberrations and other annoyances. Is that worth paying over 7x more for? That's really up to the person how much value they place on the overall quality of the field of view. Some observers who just want to see details and don't mind distractions, would get very good views through that $35 eyepiece.

But it's worth noting that even budget/mid-grade eyepieces like those ones you were looking will be a significant upgrade over most stock eyepieces. So if you're going from basic Kellners, Modified Achromats, or Plossls that came with your scope, those 58 degree eyepieces would feel like a big upgrade.

A couple alternative options to those eyepieces you were looking at:

1. Agena StarGuider Dual ED / Astro-Tech Paradigm. This is another white label brand sold by various companies under different labels. Good for the money and well reviewed. Fewer focal length choices than the 58 degree "TMB clones" though.

2. Celestron X-Cel LX. A bit more eye relief than the StarGuiders/Paradigms, but otherwise very similar.

It's worth doing some research to see what people say about those eyepieces. You generally do not need to go into premium eyepiece territory to get a big upgrade in the overall observing experience.

> My question is, is this a decent starter telescope for me to try and get into the hobby?

It definitely has its flaws and not something I would necessarily recommend for someone who is looking to buy their first scope, but since you already have it, you will definitely be able to get some good use out of it.

A few recommendations/tips:

Despite the 70mm of aperture, there are a lot of DSOs that can be observed with this scope, provided the sky is dark enough. I recommend using the 20mm eyepiece for DSOs, and eventually replacing it with a decent 25mm widefield eyepiece (Celestron X-Cel LX, or Astro-Tech Paradigm). This will hit a sweet spot that balances view brightness with magnification for general purpose DSO observing. Many objects in the Messier Catalog will be visible in this scope from reasonably dark skies. Even some objects in the Caldwell Catalog.

For lunar and planetary observing, I STRONGLY recommend you replace the cheap erect image diagonal that comes with the scope. That diagonal is meant for terrestrial viewing, but degrades the view when used for astronomical purposes. A simple non-erecting or non-correct image mirror or prism diagonal (known as a star diagonal) is recommended. It will be the single greatest thing you can do to improve the view of the Moon and planets in that scope.

For observing the Moon and planets, use the 10mm that comes with the scope. That 10mm gives you 90x magnification, which is close to the useful limit of that scope's optics. If you find the 10mm is difficult to look through or the field of view seems too narrow, you can replace it with the 9mm version of this eyepiece line: https://www.amazon.com/SVBONY-Telescope-Eyepiece-Accessories-Astronomy/dp/B07JHKP9D2/. I own it. It's an excellent value. Very sharp on-axis. Some contrast issues. Some kidney beaning issues, but otherwise comfortable to look through and a wide field of view. Can't beat the price/performance on it. It will give you 100x in your scope, which is about where I'd draw the line on its optical capability.

Welcome to the world of super-budget astronomy. You can check out Astrobiscuit on YouTube as he has many good super-budget suggestions, such as this one for low-budget planetary: https://www.youtube.com/watch?v=UhX1IPBd31g or this vid for wide-field astrophotography: https://www.youtube.com/watch?v=njk0cfnjpV8

To paraphrase, you might be able to find a decent telescope off eBay or Craigslist. For example, you can get an excellent Celestron 102GT refractor for $70 (local pickup preferred can be circumvented by an appeal to emotion by saying that you are a poor newbie in search of lifelong hobby LMAO). Or, if you are the type that likes to live dangerously you can take your chances on a telescope from Goodwill's somewhat questionable online shop such as this one which is a neat super-compact telescope decent for planetary or brighter deep space objects for maybe $80 after the bidding ends, or this big boi from the 1990s featuring computer auto-guidance and optics that will shame anything else you can buy for the rest of your foreseeable life if you can get through the bidding war and spend maybe $400 dollars (yes it goes over budget but this is a forever scope and is well worth the price if you are serious about astrophotography). Astrobiscuit personally recommends the Orion ST80 for $120 but its fast focal ratio means it is better suited for wide fields than planetary. If you want to go ultra-budget, find a good pair of modern binoculars and a stable tripod, as Astrobiscuit recommends. Or, you can wait for one of u/_Augustus's giveaways and build your own scope if you are a DIY person.

If you want to focus on planets you can forgo a mount and literally place the telescope on a chair or beanbag since planets are so bright they don't need long exposures and hence can be photographed by a cellphone taking a video strapped to an eyepiece such as the excellent SVBONY 9mm Goldline and SVBONY cell phone adapter combo. For deep space, you need a mount; as you take long exposures for faint objects such as galaxies, the Earth rotates and you will end up with very noticeable star trails as you increase exposure time. A German equatorial mount (GEM) will counteract Earth's rotation and allow you to take the desired long-exposure photos. Unfortunately, very few good GEM mounts are available within your budget (you might be able to get an Alt-Az GTI + equatorial wedge for $150 but that's if you are extremely lucky) but you might be able to 3d-print and make your own if you have access to a 3d printer, perhaps at a local university. Or, you can just mount the telescope on a camera tripod and take many (hundreds) short-exposure photos with minimal star trails then process them in photoshop and a stacking software. I can dm you some of my ultra-budget shots accomplished on a slightly more expensive setup if you'd like btw as a taste of what is possible on a shoestring budget, and you can also dm me for more advice or links to resources.

But yeah, extremely low-cost astrophotography is possible. haters will say that you need a proper 8" Dobsonian that goes for $800 in today's era of Bidenflation and supply chain issues, but it is possible and if you manage to pull it off you will get hooked on it faster than a 12 year old kid will get hooked on fortnite vBucks lmao. It might be frustrating trying to get such an ultra-budget setup working but the immense satisfaction is well worth it and you will look upon the nights you spend exploring the skies on a shoestring budget as some of the best. I am one of that demographic lol if you have more questions feel free to dm me. Clear Skies, SF

If it were me, I'd get a nice 8-10mm. This will give you 120x-150x which is a nice sweet spot for most DSO. The 9mm goldline is a good start. Next step up in quality would be something like the Starguider ED/Paradigms. From there your looking at a pretty big price jump to something that's objectively "better."

And like the other commenter said, wait until the moon is gone before going for faint DSOs. It's going to be washing out your contrast right now.

The 30mm and 13mm you currently have will serve you well for most DSOs for a while.

Where you've got a gap is in the 9mm and below.

The 9mm Plossl is going to be challenging to look through. Tight eye relief, narrow field of view. I would recommend replacing that with a better ~9mm eyepiece. If you have the budget, there are lots of options here. It will depend a lot on whether you want comfortable eye relief, or as wide a field of view as possible. Lots of good options in and around this focal length. 10mm to 8mm is a good place to be. This gets you into planetary magnification territory. 10mm is a bit redundant with the 13mm you currently have, but the 13mm is not quite enough for planetary observing, whereas a 10mm is. So the overlap isn't that bad. But I would try to favor a new 9mm or 8mm instead.

If you want an ultra/hyperwide angle eyepiece:

• 9mm Nagler Type 6
• 8.8mm Explore Scientific 82 (note this is being phased out and replaced by the 8.5mm long eye relief variant, but that eyepiece is NOT as good as the outgoing 8.8mm, so try to find the 8.8mm instead of the 8.5mm if you can)
• 9mm APM XWA (100 degree eyepiece)
• 8mm or 10mm Tele Vue Ethos

If you want something with more comfort/eye relief, but a narrower field of view:

• 9mm Baader Morpheus
• 8mm or 10mm Tele Vue Delos
• 9mm Tele Vue DeLite
• 10mm Pentax XW
• 10mm Nikon NAV SW

If you want something more budget-friendly:

• 9mm Celestron X-Cel LX
• 8mm Astro-Tech Paradigm / Agena StarGuider Dual ED (same eyepiece, different brands)
• 9mm "Gold Line" (https://www.amazon.com/SVBONY-Telescope-Eyepiece-Accessories-Astronomy/dp/B07JHKP9D2/)

Anyone of those options will be a dramatic upgrade over the viewing experience through the 9mm Plossl.

After that, you can consider a higher magnification eyepiece for lunar/planetary observing when the atmosphere is steady and conditions are good.

If your initial eyepiece is 10mm (120x), then consider a 7mm (171x) eyepiece.

If your initial eyepiece is 9mm (133x), then consider a 7mm (171x) to 6.5mm (185x) eyepiece.

If your initial eyepiece is 8mm (150x), then consider a 6mm eyepiece (200x)

Sticking to roughly 40-50x jumps in magnification is typically recommended, especially when getting into planetary magnification territory.

Awesome. I would do a couple of things:

1. Replace the 10mm eyepiece that it comes with, with one that is more comfortable to look through, and offers a wider field of view. The 9mm "gold line" is a good budget option. Else, the 9mm Celestron X-Cel LX would be a step up.

2. Get a 5mm eyepiece for planetary and lunar viewing at higher power. The 5mm Agena StarGuider or 5mm Astro-Tech Paradigm are good options. There is also the 5mm Celestron X-Cel LX.

The upgraded 9mm would be good for general purpose DSO viewing for all but the largest DSOs. The largest DSOs would be best served with the included 25mm Plossl (which produces a bright 5mm exit pupil and wide 2 degree field of view). You could get a wider field of view out of a 32mm Plossl, but going wider than 2 degrees isn't really worth it IMO.

The scope is technically capable of higher magnifications, but I have my doubts that it has a parabolic mirror in it. If it has a spherical mirror, then that will make it impossible to use higher magnifications with it. So 5mm is a conservative magnification (130x), that gets you into planetary magnification range and will show lots of detail on the Moon. If the view through the 5mm looks VERY crisp and VERY sharp when the atmosphere is steady, you can opt for higher magnification later.

You can, but the problem is the telescope itself cannot support very high magnification. The absolute limit I would go to is a 9mm eyepiece like the 9mm "Gold Line" for $36: https://www.amazon.com/SVBONY-Telescope-Eyepiece-Accessories-Astronomy/dp/B07JHKP9D2

Despite its low price, it is almost as sharp and contrasty as a $250 eyepiece, and will definitely be an upgrade over the 10mm eyepiece that comes with the telescope.

HOWEVER, the eyepiece is not really the weak link, so improvements will be marginal at best. The weak link is the telescope's objective lens itself (and also probably the 90 diagonal the scope comes with - it's very low quality amici prism that badly ruins views of small bright objects like planets). I would strongly consider replacing it with a basic star diagonal like this one: https://agenaastro.com/gso-1-25-90-refractor-mirror-star-diagonal.html

The mirror will avoid introducing any more chromatic aberration that can sometimes come from a cheap prism diagonal, and since it's not an erect image diagonal, it doesn't have an annoying line in it. This is what the amici prism in the Astromaster diagonal does: https://www.cloudynights.com/uploads/monthly_03_2015/post-232934-0-79911600-1426806265.jpg

That's visible even on a high quality Baader amici prism. It's worse in the cheap one that comes with the Astromaster. Hence, the best upgrade you can make to the telescope is to replace the diagonal with a simple mirror star diagonal. The one I linked above is not the greatest quality diagonal by any means, but it's an improvement. Combine that with the eyepiece I linked to, and you will have gotten the best possible view of the planets that the telescope can muster. The only way to improve the view of the planets beyond that is to upgrade the telescope itself to something with better optics and more aperture.

https://www.amazon.com/gp/product/B07JHKP9D2

XT4.5

Not a bad deal for this scope in all honesty. A long tube 4.5" dob like this can show a lot from a dark sky. Their new price of $250 is very steep, but at $110 (as long as the mirrors are in good shape), is a good deal.

XT8

Good that it has a two speed low profile focuser. Very handy for dialing in exact focus on planets in the moon. You don't need two reticle sights though. The Telrad is excellent, but it makes the EZ finder II redundant, so don't let that sway you as having any value. The 2x barlow lens is "meh" and may not be useful depending on what eyepieces you get, but since the scope is a good value even without the barlow, might as well take it.

Assuming the optics are in good shape, considering you get an upgraded dual speed focuser + Telrad, $300 is a fair value for this scope.

Additional accessories:

11mm ES 82

• Fantastic eyepiece and a good fit for the XT8 for general purpose DSO viewing.
• Brand new it is $200
• Used prices are typically $110 to $140. I would not pay more than $125 for it, personally.

SWA 26mm, SWA 38mm, and Apertura 42

• You don't really need three low power, wide angle eyepieces. You typically only need one.
• I would get the SWA 38mm. It's the best fit for the XT8
• Brand new it's $95
• Used prices are typically $55 to $75. I would not pay more than $55.

9mm Plossl

• Don't bother. Hard to look through, narrow AFOV, focal length is a bit redundant with the 11mm anyway.
• Better options exist for not much money

Laser Collimator

• Goes for $60 brand new
• Adds convenience but isn't necessary. Still requires a cheshire collimator to ensure the secondary is collimated properly.
• The laser collimator itself needs to be collimated, and I'm not sure how easy/hard that is to do with these collimators.
• No idea what condition the collimator is in. If it's not collimated, it can throw off the telescope collimation. Risky.
• I would skip it and put the money into a simple cheshire sight tube for $20.

Neximage 5

• Skip it. If you want to get into planetary imaging, there are better options out there

Orion Imager

• Not sure why this guy needs two cameras, but skip this one as well

Large Accessory Case

• Goes for $70 new
• Not as solid or durable as a typical resin hardcase like Apache, Plano, Condition One or similar cases
• Apache 4800 at Harbor Freight is $60 and much better
• Better yet is the Plano Extra Large Sealtight Case
• I would offer no more than $25 for this case so that you can eventually put the money into a nicer case later on

Thoughts:

Given your budget is about $350, you may have to stretch it a bit in total, but I would go this route:

1. Get the XT8 (just make sure the mirrors are in very good condition. Don't agree to buy this scope until you've had a chance to look at the mirrors yourself)
2. Offer to buy just the SWA 38mm for $50 as your low power wide angle eyepiece
3. Buy this 9mm "gold line" for lunar and planetary viewing and viewing smaller, brighter DSOs (planetary nebulae and globular clusters)
4. While you can use that 9mm gold line + 2x barlow for high power lunar and planetary viewing, it will require extremely steady atmospheric conditions. Eventually you might want to get the 6mm "gold line" from that series for 200x mag. This will be more appropriate on more nights
5. For collimation, you don't really need any tools but they can be useful. Eventually you might want to pick up a decent sight tube/cheshire combo tool, but it's not necessary to start.

That is really the minimum arrangement of scope + eyepieces that I recommend. All-in it would cost you $386 ($300 for scope, $50 for SWA, $36 for 9mm "gold line").

Just keep the two eyepieces in a small box with foam or cloth to keep them safe until you can open your budget for a proper eyepiece case.

Great reply from /u/skul219.

I'll just elaborate on some of your questions/goals

Planetary viewing

Planetery viewing is one of the most challenging aspects of visual astronomy. While it seems like it would be easy since the planets are bright and easy to locate, the reality is that their details are very small and very susceptible to massive distortions from the atmosphere, thermal gradients mixing and swirling in the tube, a warm primary mirror causing air around it to warm up, and mix with cooler air, causing even more thermal degradation. Have you ever looked at an object at the bottom of a pool and noticed how badly the waves on the pool's surface distort the shape of the object? Viewing the planets through Earth's atmosphere is very similar.

Some nights offer more stable atmospheric conditions than others. The variation can be significant even from minute to minute, or hour to hour. You might be looking at the planet and see nothing but a horrific blurry mess that you're not even sure is a planet, and then a moment later an eddy of stable air passes by and the planet resolves into a tack sharp orb rich in detail, only to have that detail erased again a few seconds later.

Beyond the atmosphere, there are other factors: planetary altitude (the higher in the sky, the better), thermal acclimation of the telescope is vital, collimation is important etc.

I strongly recommend reading this article to get a better understanding of all the factors which can influence how clear the planet looks at the eyepiece:

https://medium.com/@phpdevster/help-i-cant-see-detail-on-the-planets-ac27ee82800

Regarding what detail you should be able to see in an 8" dob with reasonable quality optics, and when all conditions are favorable, you should be able to see the following:

Jupiter

1. Swirls, festoons, and white ovals in its clouds
2. Shadow transits of its moons across its surface
3. The moons themselves in front of Jupiter (they are easiest to spot when at the limb since the limb is often darker than the middle)
4. The Great Red Spot and little details within it
5. Jupiter's shadow eclipsing its moons as they disappear behind it

Everyone always remembers their first look at Saturn because of its rings, and while it's a beautiful planet, Jupiter is the jewel of the solar system IMO. So many things to see on it, lots of dynamic interactions from its Moons.

Saturn

1. Its major cloud bands
2. The Cassini Division in its rings
3. The shadow of the planet being cast onto its rings at quadrature
4. 4-5 moons depending on how dark your skies are

Mars (near its oppositions)

1. South Polar Cap
2. If present, hazy blue/white clouds near the North Polar Cap and at the limb (where they will be densest)
3. All kinds of dark albedo features

Mars is almost as interesting as Jupiter IMO, but the challenge is that it's about 1/2 the angular size and only every couple of years. And even then, the "good" oppositions only come around every 13 years or so.

Eyepieces

None of the 8" dobs come with great planetary eyepieces. The AD8 or Z8 come with a 9mm Plossl for 133x. This is enough for planetary observing and a conservative magnification for when the atmosphere is not steady, but the narrow field of view and tight eye relief of a 9mm Plossl can make planetary viewing uncomfortable, and comfort should not be underestimated.

The Sky-Watcher 8" Classic I think comes with a 10mm Plossl, which has similar issues.

I would strongly recommend getting a reasonable quality 8-9mm wide angle eyepiece with decent eye relief to give you a better viewing experience with the planets. While a higher quality eyepiece won't necessarily improve the overall optical clarity of the planet (most eyepieces, even cheap ones, have good performance), what you gain in longer drift time from a wider field of view, and comfort from longer eye relief, can make a big difference.

A cheap but good option is the 9mm "gold line" or 9mm "red line". These are the same basic eyepiece as far as I know. I own the "gold line". It's very good. Not perfect, but very good.

A step up would be something like the 8.8mm Explore Scientific 82 degree eyepiece. Wider field of view, a bit easier eye placement. Also a "lifetime" eyepiece.

An alternative would be the 9mm Baader Morpheus. Narrower field of view than the Explore Scientific, but much better eye relief. A lot more comfortable to use.

Beyond that, you get into premium eyepieces like Pentax, Nikon, and Tele Vue. These will offer very, very marginally better sharpness and contrast over other eyepieces, but you would be extremely hard-pressed to see it.

But an 8-9mm eyepiece is only the starting magnification range for planetary viewing. You'd also want something around 200x (which is a 6mm eyepiece), and if your atmosphere is very steady, something around 300x (which is a 4mm eyepiece). But before you go buying those shorter focal lengths, I agree with /u/skul219 and others - start with the conservative magnification range (8mm to 9mm). You will definitely need such an eyepiece for planetary viewing, but I would just start there, and only add shorter focal lengths for higher magnification when you finally have a view that is razor sharp in the 8-9mm eyepiece you choose to start with. Adding magnification when the view is blurry, actually makes everything worse. Bigger does not always mean better!

Deep Sky Viewing

This depends entirely on your light pollution levels, and of course, observing experience. Once you've gotten used to seeing in the dark, from a dark sky, you will see things like dust lanes and star clouds in the Andromeda Galaxy, spiral arms in M101, M51, M33, and other face-on galaxies. You'll see nebulae and star forming regions in galaxies like M33 and M82. You'll see the dark dust spot in M64 that gives it is name - the black eye galaxy. You'll see the extended football shape of the Dumbell Nebula (M27), as well as the two "eyes" of the Owl Nebula (M97).

Emission nebulae like M42 and M8 will show lots of lovely detail.

Star clusters will look richer and fuller under dark skies.

There will be thousands of faint galaxies at the edge of your detection capability.

If you live under heavy light pollution, then unfortunately only a couple of objects will be visible, and they will not offer much detail.

Other accessories

Learning how to find objects is the biggest challenge that most people face when starting out. For this reason, I do recommend starting out with a couple of accessories:

1. If you buy a dob that has an optical finder (Apertura AD8, DT8, Zhumell Z8, Sky-Watcher 8" Classic), then I recommend adding a zero-magnification reflex sight like a Telrad or Rigel Quikfinder. They project a small red reticle at infinity through a tinted window. You keep both eyes open so you can see the sky easily, and then look through the finder with one of your eyes, and you see a red reticle seemingly projected onto the sky. This makes it very, very, very easy to roughly aim the scope at brighter reference stars.

2. If you buy a dob that already has a red dot reflex sight (like the Orion SkyQuest XT6), then I recommend buying a 2" wide angle eyepiece like the 30mm GSO SuperView (this actually comes with the Apertura AD8 and Zhumell Z8). You would then roughly aim the scope using the red dot sight, and use the wide angle eyepiece to start star-hopping to the target you want. https://skyandtelescope.org/astronomy-resources/using-a-map-at-the-telescope/, https://britastro.org/node/12846

Star hopping is a skill that takes practice and it can feel frustrating. Especially in a dob where everything is upside-down and backwards. But it's a very valuable skill to have, and if you learn it, you can avoid buying an optical finder for your dob entirely since you can easily aim the scope to a starting reference point with the included red dot sight, and then use the low power, wide angle eyepiece as a substitute for a finder scope.

1. Great choice
2. Consider replacing the 9mm plossl that the scope comes with, with this 9mm instead. 9mm is a great focal length, but not in Plossl form. The eyepiece linked offers better eye relief, and wider apparent field of view. Useful for planets and many DSOs.
3. Get a Telrad or Rigel. Makes rough pointing the scope super easy, and then you can use the finder scope to zero in on the target
4. Get Turn Left at Orion to help you get familiar with the scope, the night sky, and some finder charts for the more prominent objects.
5. Observing details on the planets is hard. I recommend reading this article. to optimize your chances
6. If your atmosphere is stable and conditions are right, and the planets look nice and sharp and crisp in the 9mm, it means you can add a higher magnification eyepiece in the 6mm to 7mm range. Which one to get depends on your budget at the time you're ready to buy it.
7. It comes with a laser collimator, but you will want to make sure the collimator itself is collimated. I also recommend getting a cheshire or collimation cap to help collimate the secondary mirror. A laser cannot fully collimate a secondary. You need a cheshire or collimation cap to ensure the secondary is centered under the focuser and rotated square to it. Laser can only help with tilt.
8. Enjoy your 2 weeks of complimentary clouds

Yes, I do recommend replacing the 9mm Plossl that comes with the scope with something a bit better. 9mm is a great focal length for doing planetary and lunar viewing (and viewing smaller brighter DSOs), but the eye relief of the Plossl design is very tight (you have to mash your eye into the lens to see the field of view), and the field of view is rather narrow. It basically makes the eyepiece feel less useful than it is.

A good replacement that doesn't cost a lot of money is the 9mm "Gold Line" eyepiece.

You can find them for less than $25 on Ebay (new), but you have to wait about a month for them to ship from China.

If you're willing to pay a bit more, you can get them in a couple days from Amazon for $36.

I own this eyepiece, and it's very good for the money. Much better eye relief, and a wider field of view than the Plossl.

That's the only accessory I would recommend buying up front since it will definitely enhance the experience with the scope and doesn't cost that much money. After that, I would wait until you and your son have had some time to play with the scope a bit before investing any more money.

To get the most out of looking at planets with it, I recommend reading this article: https://medium.com/@phpdevster/help-i-cant-see-detail-on-the-planets-ac27ee82800

Observing planetary detail can be hard even in big apertures. I don't know what latitude you live at, but right now the two major planets (Jupiter and Saturn) are quite low on the horizon for much of the Northern Hemisphere. This makes it harder to see clean views of them. Mars is also far away right now and is barely a dot in big telescopes. It won't come around again until fall of 2020, but it will be at a decent altitude above the horizon for most of the world when it returns, which will give you a better chance to see detail on it. Jupiter and Saturn will be back in the night sky in mid to late summer, but again, they will be low on the horizon depending on how far north you live. Some nights will show great detail, others not so much.

Either way, make sure the scope is fully thermally acclimated. It has a cooling fan to help it acclimate faster, so take it out 1-2 hours before you plan to observe a planet, turn on the cooling fan, and then wait for the planet to be at its highest point in the sky. That will give you the best chance of seeing detail (using the 9mm eyepiece).

An 8" scope will show loads of detail on Jupiter on steady nights.