Rob_UK_SE

That’s fantastic news, Stu. Jupiter and Saturn are rather special so what great targets for your new telescope’s first outing. Given the larger aperture of your dob, you could use a ND filter to reduce some of the overall brightness of the moon - if you enjoyed observing nearer to its full phase. You may already be familiar with these targets, but if not: it’s worth heading to Lyra where you could explore both the Ring Nebula (M57) as well as the double double (near Vega). I would also recommend exploring Hercules which is still in a fair position. Both M13 and M92 are lovely clusters. Another good target (from light polluted skies) is Albireo in Cygnus. In a similar part of the sky to Jupiter and Saturn, but higher, is the wild duck cluster (M11) in Scutum which is also rather nice.

Shorter plossls have very tight eye relief which is less (in mm) than their focal length. An 8mm plossl might have 6mm of eye relief, for example. Classic designs, such as plossls and orthos, can provide excellent views, but tend to have a 50 degrees field of view or less. Combined with their tighter eye relief, you may not find them particularly comfortable in their shorter focal lengths and, for this reason, they are not necessarily well suited to telescopes on manual mounts (although many experienced astronomers do use them in this way for specific applications). Planetary eyepieces is a more generic description for an eyepiece that has excellent contrast, minimal light scatter and sharp optics across the full FOV. They are often more simple designs (with less lens components) that may assist improved light transmission too. I say ‘may’ because the recent advancements in eyepiece designs have resulted in some very superb examples which are all of the above, while having wider fields of view and being comfortable to use too. However, some planetary observers very much prefer a narrower FOV to frame a planet / the moon as well as the previously mentioned characteristics of orthos and plossls. We are fortunate to live in a time where many options are now available to us in the astro community. 😀 Could you, perhaps, share a little more detail of your eyepiece preferences so that we can offer more specific ideas of which eyepiece/s might work well for you. For example: Do you prefer wider/narrow fields of view? Do you need more eye relief to assisting observing while wearing glasses? Do you have a specific budget?

The 8mm and 6mm Ethos require a bit more out focus (than the others) so I would have thought you should be ok. The barlow might even bring them closer to the focus position of the others.

Having owned both, I am pretty sure both the Powermate and ES Tele Extender both required some inward travel, not huge amounts, but certainly some. They are both more expensive because of their telecentric nature (the focal point does not change).

They are both really useful so I don’t think you would have made the wrong choice buying either of them. As the Antares is not telecentric, you will find that both the focus position moves inward and the eye relief increases, but you may find the latter beneficial as the shorter length Ethos feel a little tighter anyway (maybe it’s just me?). It is a well respected barlow that is both lighter and shorter than the 2x Powermate. There are various reports from people describing it as very transparent. I would have thought it would therefore be very well suited to your Ethos and refractor.

That looks like a lovely place to ‘rough it’ for the weekend... what a beautiful setting. Those skies sound ideal too 😀. Under skies that reveal the true beauty of the night sky, I sometimes just enjoy sweeping through the Milky Way and discovering points of interest along the way. I then search the charts to see where I have arrived (a somewhat reversed approach to locating objects). Most impressively, in addition to packing your scope, you also managed to book clear skies for your weekend too!

Do you ever travel with your scope, Mark? If not, it might be worth considering heading south or west to some darker skies? Even just to see the Veil - it’s in a good position for a few more weeks to come. Some areas within the Isle of Sheppey appear to be Bortle 4 (20.85) and a trip down to parts of Kent or East/West Sussex would give you slightly darker skies than that (21+ in certain parts). I can see the Veil quite clearly from home (with an OIII filter) which is 20.68 according to the light pollution map.

This thread is particularly for those that have multiple scopes - whether different sized refractors, dobs, newts, Maks, SCTs, RCTs etc. or any wonderful combination. All opinions / thoughts welcome. Given the volume of cloud cover so many of us endure, when you have finally have some clear skies to enjoy, how do you choose which scope gets to see those stars? For me, both my current scopes take a little time to put together (neither would ever be described ‘grab and go’) so it’s usually based on the moon phase. The dob gets all the new moon action, when the skies are nice and dark, while the frac gets those in-betweens! If it’s a full moon, I usually pass. The scopes I’m currently missing are the ‘quickly get it outside as there might just be a small break in the clouds’ and the ‘pick it up, park it down, let it cool and flick through SGL’. Do you have more than one scope? If so... ....which one/s more frequently get to see those stars? ... how do you choose which one to take out? 😀

That’s a lovely setup, John. A very high quality mount with a very high quality telescope! 😀 ...sorry to hear about the clouds. It’s not looking promising here either.

Given your scope requires frequent nudges instead of having tracking, the Ethos range would provide a much wider field of view. The benefit of this is less time nudging and more time observing as well as being able to frame objects at higher magnifications. 😀 In turn, as you increase magnification (while still suitably framing DSOs) you also darken the sky background - thus improving contrast. The Ethos range, due to their 100 degree FOV, can also make it easier to find objects in the night’s sky. As long as you are ok with the 15mm eye relief, the views through Ethos are unparalleled... however, they are also much more expensive than Delos / Delite and, in my opinion, become rather addictive too (hence the ‘can of worms’ comment)! Ethos optical performance is very similar to Delos with, perhaps, slightly improved transmission in some of the Delos range when galaxy hunting. I have settled on a set of 21/13/8/6 Ethos, but it has taken me a long time to get there and I will echo what has already been said about trying to purchase second hand. If you are looking for the ‘ultimate’ Tele Vue set for your scope (assuming that you are observing from rural or only moderately light polluted skies) then I would recommend the 22mm Nagler, 13mm Ethos (simply stunning) as well as 8mm and 6mm Delos or Ethos. This is based on a focal ratio of f5. Whether or not to use a paracorr is very a personal preference. I don’t use one at f5 and only really notice coma at longer focal lengths, but others may find it much more objectionable at this focal ratio. The 22mm Nagler could be substituted for a 21mm Ethos, but they have become hugely expensive and the 22mm is just so comfortable to use as well as being very immersive too. The 13mm Ethos is a true work horse eyepiece and could very well be the only eyepiece you use for much of an evening’s views. If you were looking to buy just one to start, I would go for the 13mm Ethos. The 8mm and 6mm Delos are superb and, if I was starting my set again, may very well have found a home in my eyepiece case. I quite often look through Delos eyepieces when observing through a fellow astronomer’s set and scope. I am always impressed by the views they present.

Tele Vue eyepieces certainly have some sort of ‘lure’ about them, but I wouldn’t discount some of the excellent offerings from other manufacturers such as the Explore Scientific LER 92, Pentax XW, Baader Morpheus and APM (100s, etc.), to mention a few. If green and black is your preferred route (they are lovely eyepieces), I would recommend that you base your preferences on the preferred field of view. Plossls have the narrowest FOV at 50 degrees, Delites are 62 degrees and Delos add a further 10 degrees. Ethos opens up a whole can of worms! Of the three you mentioned, the Delos are probably the most suited to your dob due to their 72 degree field of view. I would certainly recommend the 14mm and 8mm focal lengths as being ideally suited to your scope. The 8mm is well suited to the low position of Jupiter and Saturn for the next 12 months too. Mars can be tricky and is very dependent on seeing conditions and whether there are dust storms on the surface. Hopefully October will treat us to some good seeing this year. For wider field views, I would recommend a 22mm Nagler as it also has excellent eye relief as well as an 82 degree FOV. These three would be a good workhorse set and could be expanded to include a 10mm, 6mm and 4.5mm should you wish for closer steps and/or greater magnification in the future.

What a wonderful telescope and travel companion. I’m sure the views will be simply exquisite. 😀 It’s certainly a ‘keeper’ scope for life. Just a suggestion, it might be worth editing the first (box) image to remove some of your address details and phone number (for security reasons).

This is my ‘not very grab and go’ refractor setup. It’s a TS Optics 130mm f7 triplet APO (FPL-53) and I have been very pleased with the optics. The mount is an Altair Sabre 2.0 with a heavy duty plate clamp. It sits on a Berlebach Uni 18. Although not used initially, I have found a 16” extension pillar has become essential kit in order to safely observe near the zenith. It’s quite a heavy setup overall, But no single part weighs more than 10kg so it is quite manageable.

I intentionally don’t keep records of exactly how many nights I manage to get the scopes out each year (I might find it a little depressing to know the actual number!), but I can certainly empathise with those long durations when it feels like they aren’t getting anywhere near enough use. I also find it rather amusing that so many clear nights seem to coincide with a full moon! Over the years I’ve also come to terms with accepting that it’s absolutely fine to have clear skies outside, but then not get the telescope out. I might sit under the stars for a while or may just give it a miss. With all this said, I am sorry to hear of your woes with cloud cover (which we do appear to be cursed with for much of the year in the UK), particularly after the long wait for your new telescope. As much as certain states in the USA have some exceptionally stable skies, I am also under the impression that some of these same areas also really suffer from significant amounts of dust - bringing a whole different set of challenges! I have tried observing from dark sites in Ontario, Canada and discovered (to my cost) that it was almost impossible due to the sheer amount of mosquitos! I guess we can’t have it all, but I’ll take those joyful moments of clear and stable skies that, most conveniently also don’t coincide with a full moon, family commitments or an early start for work the next day 😀. There’s one thing for sure in this hobby (definitely not the weather) - at least the stars aren’t going anywhere.

Thank you, Grant. M13 looked like it was coming together nicely. 😀 As a visual astronomer, I am always amazed by the density and resolution achieved by high quality astrophotography kit when capturing clusters. Thank you for sharing your insight into the project and also the link to today’s broadcast. Looking forward to the Veil.

The best I can find in the South East is Bortle 4. Home is 20.68 and my slightly more remote -darker- site is 21.41. Home Away

I think we must have, unknowingly, been playing a game of ‘snap’, Ed. 😀

For £47 each you can’t really go wrong with BST starguiders. FLO offer a discount when you order two or more. https://www.firstlightoptics.com/bst-starguider-eyepieces.html They have a 60 degree field of view which is certainly wider than the typical 50 degrees associated with standard plossl eyepieces. For a 10” dob I would recommend the 25mm, 12mm and 8mm to begin with. Not all eyepieces are created equal and spending more isn’t always about improved sharpness, contrast and transmission. The amount of eye relief and achieving wider fields of view are very much factors influencing the design and ultimate price of modern day eyepieces.

You shouldn’t have too many problems seeing Jupiter and Saturn from light polluted skies. Jupiter, in particular, is often best observed during twilight anyway. With the exception of Mars (especially this October during opposition), the planets are not very well placed at the moment. Jupiter and Saturn won’t be at higher/better altitudes for another two years. You can certainly enjoy them, but they are not so accommodating to higher magnification. It would be worth considering how important a goto (motorised) mount is to you. If your wife is happy to learn the night’s sky, then a manual Newtonian scope (such as a dobsonian) is the most cost effective. Due to its simplicity you are able to maximise the telescope’s available aperture for your budget. The goto scopes are more expensive due to their more complex electronics and motor / gearing parts. Light gathering is all about the size of the telescope’s aperture (primary mirror or lens objective size) and this will have the biggest impact on seeing deep space objects. In the most basic terms, the bigger the mirror/lens, the brighter a DSO will appear (this is of course subject to light pollution and some telescope’s design). An 8” dobsonian, such as the Orion XT8 or Sky Watcher 200p, makes many many DSOs accessible. In terms of magnification, the limiting factor is usually atmospheric conditions rather than the size of the telescopes optics. Whichever telescope you choose, it will show you the biggest improvements when you take it to darker skies. Therefore something that can be comfortably moved/transported should also be part of your decision making.

When I have previously had Sky Watcher dobs I have made this change too. The solution was the following: 1. M54 adapter for the focuser. This replaces the one shown in your final picture and benefits from two securing points and a brass compression ring. This is currently available from FLO https://www.firstlightoptics.com/adapters/astro-essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html 2. I found that I needed a 2” replacement tube with a 35mm optical path. When using a non-flush mounting 1.25” reducer adapter this worked well and fit correctly. If you use a 50mm one you may struggle to achieve focus with some 1.25” eyepieces. Omegon were the only company I could find offering an 35mm extension tube. Below is a link to Astroshop who have them in stock. It also has a brass compression ring. https://www.astroshop.eu/extension-tubes/omegon-2l-extension-tube-35mm-optical-path/p,54437 3. 2” to 1.25” reducer adapter from FLO. https://www.firstlightoptics.com/adapters/baader-2-to-125-reducer-adapter.html The other focuser upgrade available for Sky Watcher scopes is the Lacerta 1:10 microfocus unit: https://www.365astronomy.com/Lacerta-Dual-Speed-1-10-Microfocus-Upgrade-Kit-for-Skywatcher-Crayford-Focusers.html ... when you add everything up you are looking at quite an investment, but it does protect your lovely eyepieces from barrel marks.

I find that, in less than perfect conditions, it can be useful on Jupiter and Mars, but it is much less effective on the other planets and the moon. I would, however, rather have excellent seeing conditions and unfiltered views of the planets. There is, in my opinion, no appreciable difference when it is used on Saturn, for example. I don’t use it for DSOs at all, but it may help under more heavily light polluted skies? It doesn’t necessarily improve contrast on the moon, but I do like the change in colour tone when using it on my Nagler zoom, under certain circumstances. The slight coffee tint of the 3-6N is replaced with a cooler tone which is just a little closer to the Ethos/Delos/Delite presentation. I am not suggesting that the filtered view is a more natural tone or necessarily improving the resolution either. ...it’s definitely a marmite filter, but I also like marmite! I am mindful that this thread is about OIII filters, but hope this can be of help to your query.

Thank you, John. I suspect that I might have had more luck (with the mounting holes) if it was a Synta telescope, but who knows! I’m sure your OO scope is wonderful to use - especially with a CR2 attached too. 😃 The owner would have, ideally, liked to purchase the CR2 instead, but none were in stock (anywhere) and, on reflection, the price made it a bit too out of reach once all the other required components are purchased. As the owner also uses Tele Vue eyepieces (high power Delos trio, 13E and 22N) they do appear to focus a little further out from the OTA - the Ethos, in particular. I‘m pretty sure that a MoonLite 1.5” extension tube will be required for the Ethos too.

Thank you - that’s a great idea.

I spent a happy afternoon (today) working on a fellow astronomer’s Bresser 10” dob. While the stock focuser is quite good, this particular one had developed a number of issues which included creaking in the cold (last winter) and a very rough movement, even after being re-greased and adjusted. In short, a decision was made to say ‘farewell’ and welcome a new bit of eye candy - a MoonLite CR1 classic focuser in red. For those who might be interested in changing the focuser on their Bresser dob, I’ll try to share the journey below. It was fairly straightforward, but did take me a little longer than originally planned! A speedy delivery of the focuser from FLO and mounting plate from 365 Astronomy. It’s a really well engineered focuser which feels very substantial and has a lovely smooth movement. The top part of the old focuser tube was unscrewed... ...followed by removing the focuser gear to access the lower screws. Then began the game of trying to choose/match the most appropriate threaded holes on the rear of the adapter plate to both correctly seat it as well as align the focuser tube correctly. It was almost a frustrating as monopoly! After a fair but of trial and error, these are the ones required for the Bresser dob’s pre-drilled holes. However... In spite of Moonlite’s best efforts to offer lots of options on the mounting plate, the Bresser holes did not perfectly line up to the holes in the OTA. As a result, I had to (carefully) file them to be better aligned to the required bolt locations. Care was also taken to protect the secondary mirror and capture all of the metal filings (the scope laying on the ground too). After what was far more time taken than was -probably- necessary, the holes were lined up ready to accommodate the base plate bolts. They are fixed from inside the telescope and fit very securely indeed. The next part was adjusting the focuser’s collimating grub screws (next to each bolt) so that the focuser mounted flush to the base plate/adapter (collimation will follow later). ...and there it is, all fitted and looking rather posh (if I do say so myself)... I’d quite like one now too!

The two CCD-specific ones concentrate on 95%+ of the 501nm line region, but the 6mn (being tighter) doesn’t provide anywhere near the same % transmission of the 496nm part. Their respective differences are more about suitability for the camera/sensor being used and the focal ratio of the telescope. They both work well for imaging as, in addition to improved contrast around OIII regions, they also provide a solution to some of the many challenges created by light pollution (the 6nm filter, in particular). I assume that the 6nm one simply requires longer exposure times? I have not personally used a CCD-specific filter to observe visually, but I would also assume OIII observations are still achievable. However, the view would be dimmer, when using the 6nm version, due to the reduced OIII bandwidth. The 12nm version should be similar to the visual one which, unlike your CCD version, doesn’t contain the added IR-blocker as it is not required. The highly praised visual OIII filters provide 95%+ of both 496nm and 501nm OIII lines. Below is the 12nm CCD OIII filter: