Second Time Around

The amplification factor of a Barlow will vary from eyepiece to eyepiece depending on where the focal plane of the eyepiece is situated. So the stated amplification factors are only approximate. The amplification factor also depends on the distance between the Barlow and the eyepiece. With some 2x Barlows the lens cell can be unscrewed from the tube and screwed into the filter cell of the eyepiece. This gives an amplification factor of approx 1.5x as posted by RT65CB-SWL. First Light Optics do their own version (probably identical to branded versions) for only £27. In fact, they currently have an open box return for £24. Go to https://www.firstlightoptics.com/barlow-eyepieces/astro-essentials-125-2x-barlow-with-t-thread.html You can also add an extension tube(s) (£16 each) between such a Barlow to increase the magnification (within reason). See https://www.firstlightoptics.com/adapters/baader-dt-4-1-31-8mm-nosepiece-extension-18mm-long.html Each extension tube on the Barlow I linked to above will add about an extra 0.25x amplification.

I'd recommend the Bresser Dobsonian. I did head to head comparisons and found that because of the large bearings it has a better mounting than the Stella Lyra (made by GSO). You can change any other component relatively cheaply but not the mount. I also found that with this style of mount I could carry one size bigger scope than the GSO and most other competitors. The Bresser also has a very good focuser, that can be upgraded at low cost to a dual speed. Normally, the Bresser's 6x30 straight through finder would be a disadvantage, but I'd prefer it to a RACI finder when used in conjunction with a Starsense Explorer unit. The latter of course is the main finder anyway.

Vixen NPLs have twist up eyecups. However, they're either up or down. If you want an intermediate position all you need to do is add an elastic band or hairgrip at the desired position.

The Orion Optics mount that vlaiv mentioned is probably the Rolls Royce of Dob mounts. It's all aluminium so won't rot or need maintenance. It's also very smooth, very lightweight and has a small footprint. The design means your telescope tube can be rotated and moved up and down for balance. I wouldn't part with mine. The only downside is that it's expensive.

Also have a look at the Bresser Dobs. These have large altitude rings that not only make for a smoother mount, but also make excellent handles. In fact, because of this I found that I could handle 1 size up compared with Skywatcher or GSO Dobs (the Stellar Lyra is a rebadged GSO).

What a bummer! More importantly, was your son ok?

Dual fit 1.25/2 inch - without an adapter. I'm not parting with mine!

Superb!

Thanks, Bosun. However, I tried this and all sorts of other things as I described either here and/or on Cloudy Nights a year or so ago. Nothing worked. Neither did anything that Celestron suggested in my correspondence with them. This was using Android 12. It may be that now the phone has updated to Android 13 the problem has been solved. However, I have to keep this phone permanently on and charged due to a family illness. So the Pixel 6 is dedicated to this and my wife's old Pixel 4a5g is dedicated to Starsense Explorer. Thanks again for the suggestion though.

Works on my wife's old Pixel 4a5g but not on my Pixel 6.

It seems to me that the question is whether the item is faulty or not. This may help. What to do if the item is faulty: https://www.which.co.uk/consumer-rights/advice/what-do-i-do-if-i-have-a-faulty-product-aTTEK2g0YuEy Of course you can't tell if it's faulty without using it. So if the item is indeed faulty RVO can't fall back on their terms and conditions as they're superceded by consumer law. To be fair to RVO, many retailers are unaware of this. This was a problem I had in my career as a business consultant.

That's a superb lens for milky way shots and was my choice until I had to sell it due to poor health.

If I'm on the other side then my head and body will be some 2 1/2 inches to the right (the distance between my eyes), and thus part of my body will be past the end of my tube.

I like the eyepiece on the left hand side of the tube looking up from the main mirror end. This is because my left eye is my dominant one. This means that the heat from my body doesn't waft in front of the open tube and cause turbulence and so degrade the image.

You beat me to it, Robert! I was just posting something similar and fully agree. With binoculars, the larger number divided by the smaller gives the exit pupil. If this is bigger than your own pupil size you'll be wasting light. In built up areas even a young person's pupils are unlikely to dilate (i.e. widen) to larger than 5mm. It's even worse as you grow older as then your pupil possibly won't even dilate that much even at the darkest sites. Something else to bear in mind is that the majority of 7x50 binoculars have in practice a smaller field of view than most 8x42s. I always say binoculars are like a pair of shoes. Just as feet differ, so do faces, and what suits one observer won't suit another. So I'd strongly recommend that you go to a camera or binocular store and try some out for yourself. If you don't have one nearby then order from a retailer that has a no quibble returns policy. The forum sponsor First Light Optics is one such retailer and has a first class reputation.

Yep, my VX10 has a mirror fan. In fact, the whole series does.

If you want a really comfortable bed look at those in fishing tackle shops or the fishing department of somewhere like Go-Outdoors. They're way better than any camping bed, that anglers moved on from decades ago. Those without a famous name are surprisingly inexpensive because of high volume. Many also convert into chairs. The only downsides are that they're a little heavier and bulkier.

Love that 2nd photo, especially the lighting on the rocks!

The mount is smooth enough to track by hand at low to medium powers. If you do lose the object you can just refind it by touching the object on your phone screen and following the arrows. However, with the zoom eyepiece you'll not have to do that often because, as I mentioned, you can just zoom out and almost certainly the object will then be in the field of view again. I've now passed the scope (but not the Starsense Explorer unit) on to a couple of beginners. Using the zoom at 9mm plus the 1.5x Barlow gives a magnification of 117x. That's about the practical limit on this lightweight mount. Yes, you can go higher (I've gone to 150x), but the vibrations will take longer to settle. In fact I seldom used the Barlow at 2x because 1.5x is more useful. As a broad generalisation, for most DSOs I used the zoom without the Barlow. This gives 26-78x. For the moon, planets and most double stars I used the zoom plus the 1.5x Barlow. This gives 39-117x, although in practice I'd more often be using 78-117x. A further tip is that if you're looking for an equivalent focal length of say 6mm, you'll get a wider field of view with the zoom set at 9mm with a 1.5x Barlow compared with the zoom at 12mm and a 2x Barlow. This is because most zooms have a wider apparent field of view at their lower focal lengths.

Thinking further about the upgrades to the 70mm Starsense Explorer I'd suggest the order of priority would be: 1) better diagonal 2) 9-27mm zoom eyepiece 3) 1.5/2x Barlow 4) 32mm Plossl I'll change my original post to reflect this. The reason I put the zoom eyepiece so high up is that it enables beginners to easily learn what difference a change of magnification makes on all the various classes of object. It also shows them what focal lengths would be most useful to their eyes, their telescope, and their observing conditions. In fact, I always recommend that beginners start with a zoom eyepiece. Additional, this zoom will be much better quality than the eyepieces supplied with the scope.

Something else I'd like to highlight about Starsense Explorer is that, unlike many other systems, including digital setting circles and Go-To ones, the scope can be moved around the garden without having to be set up again. This is because it doesn't need realigning. Instead you simply go back to the same object if for instance it went behind a tree, or on to the next object. This is one of the reasons I recently sold my (expensive) Nexus digital setting circles. Starsense Explorer is also quicker at setting up in the first place.

I use a 10 inch f/4.8 Dob and the lowest power on my 7.7-15.4mm zoom gives a field of view of 0.83 degrees. Starsense Explorer has never failed to get an object within this field of view. So finding the outer planets is no problem. It means that I have no need for a longer focal length as a "finder eyepiece" on this scope. There is of course some chromatic aberration with the 70mm, but as the focal ratio is f/10 I find it acceptable even without a filter. I'd add that the smaller the diameter of a scope the less the chromatic aberration for a given focal ratio. To add to Zermolo's post, a search will throw up lots of threads on converting a Starsense Explorer unit. If you have access to a 3D printer you may find this adapter of use: https://www.thingiverse.com/thing:4868065

I had the same dilemna as you with my grandkids who live in London and chose a Starsense Explorer scope. This is because in my experience the single biggest reason that beginners give up astronomy is that they can't find objects. This is even more so from cities where relatively few stars are visible to help. Starsense Explorer makes this incredibly easy. It doesn't have tracking, but if you lose the object it's very quick and easy to re-find it - much easier than without Starsense Explorer. It also gives you a list of the best objects for the night that you're observing, including those that are rewarding from cities. At the the push of a button Starsense Explorer will even tell you a lot about the objects - youngsters in particular love this. The whole process is very intuitive - my 8 year old picked it up immediately and was soon controlling everything himself. I chose the least expensive in the range, the 70mm f/10 refractor. Even though the next size up, the 80mm, is currently on special offer, I'd still go for the 70mm at £169. This is because it has a wider field of view plus, as the mount is the same on both models, it's steadier. I did upgrade some of the accessories. I bought a much better quality Celestron diagonal. (£45 from First Light Optics). There are cheaper ones, but this gives a very good price/performance ratio. The diagonal supplied with the scope isn't that good but has the advantage of a correctly orientated view for terrestrial use such as birdwatching and holidays. This is one of the benefits of choosing a refractor. Next I'd suggest a zoom eyepiece. I find youngsters in particular love zoom eyepieces. My 8 year old said it was like landing on the moon! It also helps with tracking because if you lose an object at high power you can just quickly zoom out and it'll probably then still be in the field of view. I chose a 9-27mm as it gives a particularly useful range of magnifications on this f/10 scope. Those from SvBony usually cost about £50 but are often (now for instance) on special offer at about £40. I also bought a better quality 2x Barlow lens (£27 from First Light Optics). This is the type where the bottom black section can be unscrewed and then screwed into the filter thread of an eyepiece. This gives an additional amplification factor of about 1.5x, and so triples the range of magnifications at very low cost. Finally, but this could come later, I'd suggest a 32mm Plossl (£29 from First Light Optics). This gives the maximum field of view possible with this scope of approx 2.25 degrees (the full moon is 0.5 degrees in diameter). This gives plenty of space around the Pleiades to see their full beauty - the 1.6 degree field of view with the 80mm f/12.5 doesn't. One final thought about the Starsense Explorer units is that a very simple modification means that you can move them to different telescopes where they fit into a standard finder shoe. If as is likely you buy other scopes in the future this is a huge plus. If on the other hand you don't get hooked on stargazing then the 70mm Starsense Explorer will be extremely easy to sell for a good price. In fact, I was so impressed with the 70mm Starsense Explorer that I bought another for myself and did just that modification myself!

All done on the phone, no internet access required.

We stayed here last year and can thoroughly recommend it - very dark skies near Exmoor. https://www.eddington-lodge.co.uk/