Zeta Reticulan

OK (if I pull the trigger lol).

I've been looking at the pictures of that Astro Essentials shorty. I'm pretty convinced it isn't GSO. The element resembles my comparatively recently purchased Orion 2x 'Shorty'. I have no idea where Orion source from now. I also have the GSO short Barlow. The Orion has a filter thread, and the Astro Essentials appears to have one. I thought my 2x Orion was a tad sharper than my GSO. I'm really tempted to buy the Astro Essentials now to see if the elements are the same lol.

The Pentax XL is similar to the Baader in many respects. The XF is basically a portable spectroscope (obvious CA) for astronomy, although excellent for daytime use.

I've always wanted to learn Clangon.

Hence why it is basically a convention. Otherwise we'd all be paddling up the smelly narrow sheltered waterway without a suitable rowing implement.

TBH I don't think the ST102 is particularly poor on planets for a fast achromat. The images are sharp and well defined. Although much over 125x and the CA is more noticeable. This can be ameliorated somewhat with a Wratten #8 (light yellow) filter stacked with a basic light pollution (contrast) filter. The yellow filter attenuates some of the cyan fringing while the LP takes out the sodium lines slightly naturalising the colour.

Grammar is a convention.

Making plans for Rigel ...

Oh no, not the bunnies!

I have a lot of 2x Barlows, and a fair few 3x Barlows. The vast majority of my 2x Barlows are the short type. These are often considered more suitable for use in diagonals. This is undoubtedly true. However there are compromises with the light path that can produce aberrations in use. I only have two ‘full length’ 2x Barlows. A Tele Vue and a Vixen 73674 2x Deluxe. Vixen claim that the Deluxe is intended to be used with fast focal ratio telescopes. I agree with this as it achieves focus in my f/6 Newtonian where the Tele Vue Barlow will not. Furthermore the Deluxe is fully multi-coated, has three elements and weighs 140g. The Tele Vue is multi-coated and apparently the lens cell consists of two elements of high index glass. It weighs approximately 136g according to Tele Vue. Regardless of these claims the Tele Vue feels slightly heavier to me. Although to be honest there isn’t much between them. I make the Tele Vue just over nine and a half centimetres tall, with the Vixen around two centimetres taller at about eleven and half centimetres. The seemingly overlong and detachable Vixen lens cell is around five centimetres. Making it three whole centimetres taller than the Tele Vue element. The Tele Vue features a brass compression ring complete with captive thumb screw. Its barrel has no undercut. This is in stark contrast to the Vixen’s plain thumb screw and undercut featured high on its lens cell. Generally I tend to use Barlow lenses with small and light eyepieces. This is possibly because I normally use short focal length Plossls and orthoscopics in combination with short tube refractors for lunar and planetary observing. I also regularly deploy several light, portable, grab and go set-ups. I pondered on what the lightest practical set-up might be with my f/6, 60mm ED doublet. One wide angle eyepiece giving about a three millimetre exit pupil would work. Then an eyepiece producing a one millimetre exit pupil, with finally a Barlow that could possibly work with both eyepieces. The wide angle eyepiece was a relatively easy decision and I went with a 19mm Tele Vue Panoptic. It is lightweight while producing nearly 19x for around a three and a half arc degree field of view. When used with a 2x Barlow it produces a one and a half millimetre exit pupil. These are a useful range of magnifications. Many spotting scope zooms vary from around a one and a half millimetre exit pupil to around a five to a seven millimetre one. The other eyepiece has been a less straightforward choice and can vary between a 6mm Vixen SLV, a 6mm TMB clone and a 6mm Orion Expanse inter alia. The Barlow selection was not obvious though. My first instinct was to use a high end ‘shorty’ as I imagined it would predominantly be used with the smaller eyepiece to give a half millimetre exit pupil. So less vibration at a 120x magnification. Furthermore there are weight and balance issues I have to take into consideration on a light portable set-up. Inevitably it came down to a selection between the Tele Vue and the Vixen. In a small Baader BBHS prism diagonal the Vixen protruded a full twenty millimetres further out than the Tele Vue. Although with the weight of the Vixen concentrated in the cell it had a lower centre of gravity. Visually there isn’t much difference between the Tele Vue and the Vixen Barlows. At first I leaned towards the Vixen. In my experience it has slightly better contrast, transmission and overall acuity. The brighter transmission is particularly noticeable to me, although unexpected considering it contained a triplet element compared to the doublet of the Tele Vue. This was the better choice for planetary viewing. The undercut was not a problem in the twistlock and I could live without a compression ring. The BBHS prism is much better at the red end of the spectrum than conventional prisms, as are all silver reflecting surfaces. Orange and orange-yellow stars benefitted from this particularly. The Vixen was basically used for splitting doubles and planetary observing. So, everything sorted then. Except I had a brainwave. I could use the small and dumpy little Panoptic in the Vixen. Originally I didn’t envisage doing this often, if at all. Unfortunately the Panoptic displays some edge distortion when combined with the Vixen Deluxe. In fact, it seems to start after around 60° or so of field. I wondered if this would be the case with other Barlows. So I switched to the long Tele Vue. Lo and behold the edge astigmatism was cured! In fact the Panoptic and Barlow work so well together it’s basically like having a 9.5mm Panoptic. I suppose I can always switch back to the Vixen for occasional dedicated planetary viewing sessions. Both ‘long’ Barlows have their pros and cons. The Tele Vue was the best compromise. Possibly.

I was thinking more Austin Allegro.

Difficult to say. There's more to a bino than views. A lot has to do with ergonomics, design, practicality, suitability etc.

And there's that.

The Baader are probably the best. I don't mind slumming it with the WO's lol.

I don't think the WO bino's have more than a 66° FOV. It doesn't preclude using wider angle EP's though.

That would be my guess.

More likely it's an Ubuntu thing.

A lot depends on how the binoviewer itself is attached to the visual back. Mine are just placed in a diagonal. So weight will be a factor. The next significant point to take into consideration is being able to merge the image with the eyepieces themselves. After much experimentation I'm basically down to 20mm SWAN's and 15mm SuperViews.

Looks interesting. Pity I can't convince it to translate into English.

Isn't NSWR theoretical? Like warp drive or something?

TBH I think it would have to take a huge breakthrough in something or other. The distances are just too vast for solar system exploration to become as casual as contemporary Earth based aviation for example. Space is big. I believe Jupiter is forty light minutes away, and technically that's in our backyard.

I possibly witnessed it once. It was on the 5th of August 2017. I was observing in the Grimaldi region. The Moon was almost full. I witnessed a bright flash of light near the centre of Grimaldi. After I thought it was difficult to focus on the region for a while, almost as if some sort of ejecta was present. I could focus on other areas of the Moon. After a while I could focus on Grimaldi again. It may have been a meteor strike. IDK.

I obtained my first Orion Expanse eyepiece in 2016. The 9mm is supposedly the best of the range so that was the one I initially purchased. I’m fairly certain these were originally manufactured (or at least distributed) by Barsta/BST. The series has been marketed under a variety of brand names. As far as I know they are all more or less the same apart from the branding and housing finishes. SvBony appear to have a similar line although I don’t know how or if they differ. There have been rumours that the T.S. Optics versions have better coatings, but I can’t substantiate this. There are four in this range of fairly lightweight 66° field eyepieces: 6mm, 9mm, 15mm and 20mm. The 6 and 9mm have Smyth-type barrel lenses while the 15mm and 20mm do not. My Orion 6 and 9mm have 22mm chromed brass barrels featuring an undercut. At 75mm the 6mm is 5mm taller than the 9mm eyepiece. Both have 20mm eye lenses with the 6mm having an 8mm field stop compared to a 15mm stop in the 9mm. Orion Telescopes & Binoculars claim around a 15mm eye relief for both the 6mm and 9mm Expanse. Which I think is a tad optimistic. I acquired the 6mm relatively recently. Although just over three years ago I bought a generic 15mm ‘UltraWide’ which is to all intents and purposes a 15mm Expanse. The UltraWide had a black aluminium flared barrel. My plan was to use it with a light ‘grab and go’ modified ST80 set-up. Unfortunately it exhibited a lot of lateral astigmatism at f/5 that could only be just about ameliorated with a Barlow. As it was primarily intended for rich field observing this wasn’t really an option. I wouldn’t particularly recommend the 15 and 20mm versions with anything less than an f/8 focal ratio. One aspect that I did like about the 15mm was that there were no eye placement issues. The 9 and 6mm can noticeably ‘kidney bean’ if the eye position isn’t quite right. I never thought the 15mm was quite as sharp or as contrasted as the 9mm either. Eye placement issues aside, the 9mm is bright, very sharp across the field and well contrasted. Colour separation is excellent and it is just as good on planetary targets as open clusters. It can have a tendency to ghost on particularly bright targets such as the Moon, especially if coupled with a Barlow. The 6mm Expanse is basically as good as the 9mm in my opinion. Although in my experience it can have a tendency to ghost slightly more than the 9mm version. Both Expanse eyepieces can suffer this fault primarily with lunar viewing, although having said that I have had pretty decent ghost-free views of the Moon with both of these eyepieces when used without a Barlow. There are some interesting build differences between my new 6mm and older 9mm Expanse EP’s. They are only trivial but may be indicative of different manufacturers. The Barsta site appears to have disappeared from the internet so I have no idea if they still commission products. The Expanse roll-up rubber eyeguards look identical at first glance. However, the newer 6mm Expanse eyeguard consists of a softer rubber reminiscent of the old GSO roll-up guards. These are distinctly different in feel to the eyeguard on the 9mm Barsta made Expanse. The older 9mm eyepiece has a typical Barsta/BST stiffer guard. The end caps on the 6mm are not traditionally like Orion dust caps. The embossed ‘Orion’ logo isn’t present on the 6mm and the field lens dust cap doesn’t have the number ‘317’ on it like most of my other Orion eyepieces. Although this may be due to present day supply problems. The distinct coloured band or collar at the top of the housing of each eyepiece are slightly different hues of blue. At the end of the day these eyepieces are quite reasonably priced for the performance they deliver. Compared to a lot of more modern offerings they are possibly a little antiquated. The two shortest focal lengths have some eye placement issues and the 15 and 20mm will show lateral astigmatism in faster focal ratio scopes. The advantages with these eyepieces are that they are light and relatively small with a capacious 66° field of view. I particularly like the 6 and 9mm for deep sky with grab and go set-ups. Primarily because they are relatively compact and easily carried in a pocket. Recently there have been changes at Orion Telescopes & Binoculars and they have closed their warehouse facility in the Netherlands. Whether these particular eyepieces will continue to be available is not known.

The Guan Sheng Optical ‘StellaLyra’ 30mm SuperView weighs in at a respectably lightweight 285g. It has a claimed 68° AFOV with five lens elements in three groups. The coatings seem like the usual GSO ‘green’. There is a purported 22mm of eye relief (which seems fairly accurate) and I make it 100mm tall with a folded down rubber eye-guard. The eye lens is 30mm and I measured the field stop at 35mm. The overall aesthetic is a straightforward design with a smooth aluminium barrel. Guan Sheng Optical have been gradually phasing out all of their barrel undercuts for some time now. The more recent undercuts usually featured lower-lipped flares, which aided extraction. GSO seem to have decided to replace all of them with smooth barrels. The upper housing features a rubber grip. My best guess is that the design is some form of Erfle. The internal baffling is competent and it features a 'filter' thread. The SuperView series has been a huge success for GSO in the main and they can be purchased under various brand names. I have a pair of ‘Altair’ 15mm SuperViews for my binoviewer. However, the SuperView line has been criticised by some for displaying edge of field astigmatism, particularly in faster scopes. Although why anyone expects high end performance at GSO prices is a bit of a mystery. The 30mm ‘StellaLyra’ seemed like an answer to a particular problem for me. I wanted a lightweight 2” eyepiece around 30mm for rich field viewing with short tube refractors. The weight is important to me as I have a physical disability. Heavy eyepieces can also affect balance on light mounts. Ideally I wanted to fit a small travel scope with accessories into a lightweight bag not exceeding five kilograms in total. GSO threads are usually pretty compatible with each other, but it was a bit of a ‘no-brainer’ that my 2” GSO Barlow element would be able to thread into the 30mm SuperView. Although this does add to the overall weight slightly it saves me carrying another 2” eyepiece. Depending on whether this diminishes the focal length by 1.6x or 1.5x (the jury’s still out) it reduces it to an 18.75mm or 20mm focal length. I tried the Barlow originally with a 32mm GSO RK (Reversed Kellner). The 32mm GSO RK is lightweight, and I like its ergonomics. It produces a bright and well contrasted image. It can also produce the ‘floating in space’ effect often reported in other reversed Kellner designs. Unfortunately it suffers from seagulls the size of pterodactyls in anything faster than f/8. Adding the Barlow element shoots many of the avian dinosaurs down but the fastest scope I can actually use it in is my 80ED DS Pro Evostar (f/7.5). I originally tried the RK in my f/5.8 72ED DS Pro. The results were far from satisfactory. It kind of reminded me of the scene in Star Wars when the Millennium Falcon jumped into hyperspace and all of the stars stretched out into long white lines. I’m not joking. One Wednesday in January I thought I was in with a chance as it was predicted to be clear for around an hour. Although my several different weather forecasting apps couldn’t actually all agree on which particular hour exactly (eventually I got well over two hours outside). So I ventured out with my modified ST80 and AZ5 mount at 18:00 GMT. The transparency was below average with a few scudding clouds and the seeing was about Antoniadi II~III. The first target (without the Barlow element) was Cr 70 aka the ‘Serpent Cluster’ in Orion’s Belt at 13.3x. To my relief there were no seagulls and well over 70% of the field showed no discernible off-axis astigmatism. Although to be honest I tend to predominantly observe on-axis anyway. The field stop is not sharply defined but this isn’t unusual with GSO eyepieces. The Pleiades and Hyades (Melotte 25) were stunning. I spent some time in Cassiopeia, Perseus and Auriga. NGC 559, NGC 663, the Owl Cluster and the Double Cluster all looked excellent with good colour separation and were sharp and well contrasted. I managed the Andromeda Galaxy and later even got a hint of the Crab Nebula through rapidly diminishing transparency. I added the Barlow element (for about 20~21x) and revisited most of what I’d observed earlier including M42. I was pleased to discover that there was no really obvious vignetting, although it pushed the eye relief out a bit more. The 30mm GSO SuperView isn’t a top of the line premium ocular, but there again I didn’t expect it to be. OK, maybe a few baby seagulls. It can display a small amount of astigmatism near the edge of field. I thought it did well in a short tube achromat and a pretty good 2” eyepiece for just under seventy quid. Definitely a keeper.