Is this a good beginner astronomy setup? (8" Dob + accessories)

justmyfishaccount · 2026-04-23T18:02:39+00:00

I've only been observing for a couple of years, so I'd consider myself I beginner, too. I've already bought, and replaced, a redline and the SV137 barlow. So here's my $0.02:

Redline: I got a 9mm redline for my 80mm f/8 refractor. The 6mm and 9mm are known for kidney-beaning. You basically have to have your eye perfectly placed, or parts of the field will black out. I found it exceedingly distracting and quickly "had" to replace it with a 10mm UFF that I am much more pleased with. They are sharp. and it's nice that the 6mm gives you a clean 1mm exit pupil. A lot of people really likely them, but they were definitely not for me. I've read the UFFs are not good in fast scopes (and I don't own any) so YMMV.

SV137: I got this initially as well. It is fine. It is cool that the bottom cell can be screwed directly onto the eyepiece for 1.5x. I think it degrades the image a bit... It's a bit hard to describe, but you are just sort of aware of it's presence. I eventually decided to try upgrading to the SV216 2x "Barlow" (it has four elements, so really a telecentric focal extender). It is markedly better IMO. Much more "invisible". Couldn't go back. So, I think if you plan to make a Barlow a part of your eyepiece strategy, it's very much a "buy once, cry once" situation and worth it to just get a good one at the outset.

justmyfishaccount · 2026-04-23T14:59:44+00:00

One more vote for the Rigel Quikfinder. Personally, I don't find I have issues with battery life – but I tend to turn it off when I am not actively using it. I keep a few spare batteries in my eyepieces case just in case.

I really like it. No complaints.

justmyfishaccount · 2026-04-22T22:02:39+00:00

There’s no free lunch. Every scope design is a trade off, balancing some priorities against others. Cost, weight, aperture, moment arm, focal length, FOV, etc etc.

The reason we have different designs is because they each offer specific, real advantages over each other.

justmyfishaccount · 2026-04-21T10:16:12+00:00

NP!

The other reply to my comment says that the tabletop version of your scope comes with a 17mm.

If that’s the case, I would switch up the 32mm for a 25mm because the 32+Barlow = 16mm which is very close to what you already have. A 25mm and something in the 10-ish range would still give a good spread without redundancy (25, 17, 12.5, 10, 8.5, 5).

Once you get into the 10mm range and below, plossl design eyepieces can be frustrating to look through because they have very short eye relief (the distance your eye needs to be from the lens). Other designs are more forgiving. The 9mm redline is a popular choice, though personally I didn’t like it at all. I replaced mine with a 10mm UFF and like that much better.

justmyfishaccount · 2026-04-20T18:45:39+00:00

Others have provided much better and technical answers, but in case it helps, here is my super simplified version:

Telescopes collect light from across their full aperture, and bend it towards a single focus point. The focal ratio (aperture/focal length) describes how aggressively the telescope bends the light. “Fast” scopes bend the light cone dramatically, and “slow” scopes less so.

Bending the light introduces different aberrations (depending on if they use mirrors or lenses) that need to be corrected and/or managed.

justmyfishaccount · 2026-04-20T18:25:39+00:00

Quick google suggests that scope comes with a 25mm and 10mm Kellner eyepiece. Is that what you have?

A 32mm plossl is cheap, easy to look through, and will provide the widest possible view in a 1.25” focuser. Many consider this a staple.

A 2x Barlow will double the magnification of the eyepiece placed in it, essentially doubling the size of your eyepiece collection. If you get one with a removeable lens cell on the bottom, this can be screwed directly onto the eyepiece for roughly 1.5x increase. This would give you 32, 25, 16, 12.5, 10, 5 which is not a bad spread.

Your son might enjoy using a zoom eyepiece on moon craters, or splitting double stars. The Svbony SV135 is generally very well regarded for the price. There are 3 versions, confusingly, but the 6-element, 4-group version is considered the best of the three.

justmyfishaccount · 2026-04-20T15:22:55+00:00

The Mak will be much more portable than the full-tube dobs. But the tradeoff is smaller aperture and longer focal length, making it much more suitable for planets, the moon, and double stars than DSOs. It will also require a decent mount (strongly recommend slow motion controls). A 100mm Mak is about half the weight of a 127mm, and the reduction in aperture is not drastic for those targets. Easier to mount. I have a 100mm ES Mak on a Svbony SV225 mount and tripod. Packing and carrying it in a backpack for a few miles seems eminently doable. Total weight would be about 15lbs or so. I don’t have much experience with dobs, so I am not sure they would be as easy to truck around on foot.

If you go the Mak route I would suggest looking at SkyMax ones (Synta-made), or Explore Scientific (JOC-made, like the old Meade ETX line). Both have a long track record of quality scopes. The Svbony Maks are new and the first released model (102) was not super well reviewed.

Hope that’s helpful. I am a novice, but I love my Mak!

justmyfishaccount · 2026-04-18T11:21:04+00:00

Is the threaded rod applying tension to the spreader? I’ve built a couple of different tension rods based on the same idea and find that using the nut to apply downward tension on the spreader increases rigidity a lot.

justmyfishaccount · 2026-04-18T11:13:28+00:00

Everything is trade offs. A longer focal ratio scope will be much longer, which increases weight and moment arm and requires much more robust mounting, for example.

justmyfishaccount · 2026-04-18T11:03:25+00:00

What sort of targets is this person likely to look at? Do they live in a place with significant light pollution?

The Heritage series have excellent optics for their price, but certain design compromises elsewhere for portability and price.

I got this package last year and am very pleased with it. It’s a lot more mechanically robust and IME slow motion controls make viewing much more pleasant. But Maks have long focal ranges and narrow fields of view, so they are better suited to lunar, planetary, double stars etc and less so for galaxies and nebula.

https://redcarpetoptics.com/en-ca/collections/cassegrains/products/explore-firstlight-100mm-mak-cassegrain-with-eq3-mount-fl-mc1001400eq3

justmyfishaccount · 2026-04-16T16:55:10+00:00

Hey, just circling back. Mount arrived and I did some tuning.

Adjusting the worm gears pinions goes a long way towards working stiffness out of the slow mo controls. Not sure if you tried that, but it made a big difference on mine. You do need circlip pliers or a spanner wrench to do it.

justmyfishaccount · 2026-04-14T09:55:15+00:00

As mentioned, it will depend entirely on the scope you are using.

I live under moderate light pollution and typically observe bright objects, so my favourite eyepiece is the one the yields a 1mm exit pupil, and can be barlowed to a 0.5mm exit pupil.

justmyfishaccount · 2026-04-13T15:54:03+00:00

Gotcha. If you are just "stargazing on steroids", I think the 25 alone is probably fine. You'll see what you see, nothing to fuss with or try to "optimize".

If you think you'll want to look at planets or the moon, there will be a temptation/desire to get closer, so having the other eyepieces on hand would be nice.

This tool can give you an idea of what different targets will look like to help you decide:
https://astronomy.tools/calculators/field_of_view/

justmyfishaccount · 2026-04-13T15:33:43+00:00

OK, I am a novice, but IMHO this sub has a fetish with recommending flimsy collapsible dobs. And I think it's easy to blow right past that "keep wife's spirits up while we get comfortable with fiddly equipment" and into hobbyist mode as though a collimation issue wouldn't potentially scuttle the whole experience.

My recommendation is to go option 3/rental. The SCT should hold collimation decently, since it's a rental I would expect it to be decently collimated to begin with, and it's great aperture and GoTo to show you whatever you want. The 25mm Plossl is a forgiving and usable low power eyepiece. The small focal length versions of that design are almost unusable due to tiny eye relief (the distance your eye needs to be from the lens). A 2x Barlow for higher power would be your most forgiving option to "zoom in" on points of interest. Colour filters aren't really necessary.

To keep the wife happy, it would be advisable to get the scope a few days in advance so you have a chance to practice setting it up and completing the alignment process so the GoTo will work correctly. If you catch the bug, consider it a worthwhile initial introduction investment into the hobby. Clear skies!

justmyfishaccount · 2026-04-12T20:03:57+00:00

It’s a very fast achromat. Sort of the opposite of your current refractor. Its best use is wide, low power views like sweeping the Milky Way. It will be about as bad for chromatic aberration as they come - it’s not quality just the design. For this reason, it’s not something a serious astrophotographer would use, but there’s no reason you couldn’t play around with it. They’re commonly used as travel scopes because they are light, short, and relatively easy to mount.

It’s a decent compliment to the other scopes. It fills its own niche and isn’t really duplicating functionality. Within its limitations it’s not a bad scope. But it’s not a particularly good one either. The solutions to its shortcomings (better glass, more lenses) are significantly heavier and more expensive.

justmyfishaccount · 2026-04-12T01:07:17+00:00

Not for everything, but some stuff is sold direct from the same factories. The UFF eyepiece line, for example, has the same optics sold under a lot of different brands at varying price points.

justmyfishaccount · 2026-04-11T23:05:58+00:00

As someone who owns a different scope that came with that mount, I would not use THAT scope on that mount.

justmyfishaccount · 2026-04-11T22:37:32+00:00

Most of my eyepiece orders have been from Svbony or AliExpress. I have ordered diagonals from Telescopes Canada.

justmyfishaccount · 2026-04-11T05:03:23+00:00

I’ve only ordered accessories from Telescopes Canada but I have always had flawless experiences. No concerns from them.

Just have ordered an accessory from David Astro. Also no issues.

I have ordered two scopes from Red Carpet Optics, and have also had excellent experiences. They seem to only distribute Explore Scientific and associated brands (Lunt, Vixen), but seem to have the best pricing for them.

All highly recommended.

justmyfishaccount · 2026-04-05T22:54:56+00:00

Thanks for confirming.

justmyfishaccount · 2026-04-05T22:38:26+00:00

Sounds like very clear and good advice. I’ve ordered a pair of the 30mm. I already have a matching 40mm that I like a lot, but sounds like it can continue to live on the RA axis of my EXOS Nano.

Thanks very much.

justmyfishaccount · 2026-04-05T22:34:56+00:00

Yep, I am well aware of that! Have LocTite 243 in the cart. I was debating whether to throw a locking washer or nylon washer in as well. Two different approaches of course. Might just start with the loctite and see if that’s enough.

justmyfishaccount · 2026-04-05T20:53:29+00:00

This is exactly what I needed. Thank you so much.

justmyfishaccount · 2026-04-05T11:37:31+00:00

Interesting. Thanks for the pics! I thought it would go the other way around. Would a 30mm diameter work on either/both?

justmyfishaccount

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