Rob_UK_SE

If you were to add one more eyepiece (for lower power), my suggestion would the 22mm Nagler. I appreciate that it is a considerable investment, but it is a wonderful eyepiece and would perfectly complement your trio of Morpheus. Although this sort of thing can be very subjective, I have not found the eye relief too tight (it is stated to be 19mm) and the 22N is certainly much more relaxing to use than the 21mm Ethos. I own the 21E and frequently observe with someone that has the 22N. I have always been very impressed with the views from the 22N. As a long term investment, a set comprised of a 22mm Nagler with 14mm, 9mm and 6.5mm Morpheus would make a lovely quartet and, importantly, all focal lengths would get used frequently. If the 22N is just too much of an investment, you could also explore the 20mm APM XWA which is somewhat influenced by the 21E. It has around 15mm of eye relief (so is a little tighter than the 22N) - this may not be sufficient if you wear glasses to observe. My ‘journey’ to expand the available focal lengths in my eyepiece case is the result of using both a dob and refractor. I was finding gaps in focal lengths that I would like to utilise, but that weren’t available. The new additions have largely been used in the refractor, thus far, but I look forward to using them in both scopes in the future (there are still a couple of gaps to address too). Like you, I enjoy keeping things fairly simple with the dob and, as a result, tend to only switch between 3 or 4 eyepieces during an evening. However, there have been more than a few occasions where I only use one (usually the 21mm).

I have been on a similar journey recently and also use a 12” dob... Firstly, that’s a lovely set of eyepieces, Baz - you really do have a lot covered already. Having closer spaced focal lengths (at the shorter end) is certainly beneficial, but is an area that you could thin out if you’re only reaching for specific focal lengths. Do you still reach for the Starguiders now that you have the Morpheus? My most frequently used focal lengths with the 12” are 21/13/8. Recently, I am often jumping from 21mm to 8mm, depending on the target, but do enjoy the 13mm with many winter targets. I would have thought your 9mm is ideally suited to a great many smaller DSOs as well as planetary views, with excellent contrast, in general seeing conditions. If you ‘had to’ thin things out, I would let go of the 8mm, 12mm and 18mm Starguiders and consider adding something around 20mm. I find the 4mm exit pupil from a 20mm(ish) eyepiece ideal for subtle objects like the veil nebula from non-dark sites. Spacing the low end 30mm, 20mm, 14mm, etc. is a good progression. Alternatively (as you appear to be enjoying the Morpheus so much), you could always work towards an ever so slightly larger set by adding a 4.5mm at the top end too? 😀 4.5mm, 6.5mm, 9mm, 14mm, 20mm(ish) and 30mm as a ‘complete’ set of six eyepieces.

I quite agree, John (having just attempted to read through those pages with varying degrees of success this end). I didn’t realise that using an Ethos 13/10/8/6 with the 2” barrel -into a barlow- would impact on the barlow’s ability to achieve 1.6x. I don’t like securing the 13/8/6 Ethos using the 1.25” barrel and have been considering purchasing the Antares 1.6 since hearing about Dale’s successes with this combination. It would be interesting to hear, Dale, how your 8E+ barlow compares to your 4.7E in terms of magnification. Does it feel similar, in a non-scientific way? I am wondering just how much the magnification is affected by using the 8E in ‘2” mode’? Stardaze, I’m sure that you will be delighted with the 5mm XW. I had been planning on ordering it due to the clearance sale, but you beat me to it 😀. I have recently purchased the 30mm, 10mm and 3.5mm XW to complement my Ethos set and have been very impressed with them, thus far. I have heard nothing but good things about the 5mm so I can’t imagine that it will disappoint. Hope that you get some clear skies to test it out.

Thanks for sharing this, John. The height is a little more manageable than the Powermate I feel. I really enjoyed the views through a Powermate (when I had one), but found it too heavy and tall for me at the time. ...very curious to try out an Antares mkII version.

It’s interesting to hear that you preferred the 8E + barlow last night, although I appreciate that this may well change on different nights and / or targets. Given that the original intention of the Ethos range (or at least in the marketing) was to create two ‘trios’ comprised of the 21/13/8 and 17/10/6 which both utilise a focal length spacing of 1.6, a 1.6x barlow rather perfectly augments the 8E and 6E to almost match the Ethos SX, but without the 110 degree FOV. This is certainly very appealing to me. 😀 Your feedback about the eye relief and being able to achieve focus is very positive news. As you mentioned, John, this thread has me pondering as well about the newer version.

Great to hear that all of your eyepieces reached focus with the barlow. It sounds like you have those planetary optimum (magnification) ranges covered. Considering our UK skies, 190x will see more frequent use than 200x and above anyway. I usually settle a little lower (150x) for Jupiter. Your 8E + barlow has that territory covered too. I haven’t observed through an Ethos SX yet (I’m slightly concerned about what might happen if I do!), but I am very intrigued by Al Nagler’s “Spacewalk experience” they are said to provide. I am sure you had wonderful views last night with your 4.7E as the lunar phase was quite lovely. Did you sweep over to Mars from the moon? I was very tempted to leave the scope setup outside and get up early as they were such a close pair (regrettably, I ended up not doing so). How did you get on holding your eye position with the Ethos + barlow (thinking back to the “eyepiece cups up or down” thread)? Was the additional eye relief noticeable / comfortable?

If it’s not too bad then I would recommend holding off until it really does need a clean. A truss dob is indeed easier for using an air blower, but you do have to be much more careful / aware of the mirror as it is quite exposed to the elements -especially when you are assembling it. As we live quite close to the coast, I am ever so slightly paranoid by the seagulls that frequently pass overhead. For one thing, I don’t want the centre dot on the primary mirror to promote target practice!

With a solid tube newt you can probably get away with longer intervals between cleaning - depending on how frequently it is used, the conditions you observe from and how/where the scope is stored. I tend to wash the primary every couple of years and typically before the galaxy season begins. Without question, my current scope (an ES 12” Ultralight II dob) has been the one that I have found most challenging to keep clean(ish). The mirror was washed 12 months ago and it looks rather dusty at the moment. I use an air blower before each session to remove what I can. The mirror box has a large opening on each side which allows you to lift it up with ease (a positive), but they are also perfect for letting in dust between sessions (not so good). I resort to covering everything with a large towel in an attempt to keep the dust at bay. In contrast, my old Meade Lightbridge 12”, which had a plastic cover for the primary, is looking cleaner than my ultralight... after selling it some 8 years ago (I use that scope occasionally with its new owner). Ironically, the owner has never cleaned the mirror either!

I try not to worry about the odd spec of dust or very light ‘touch’ where my eyelash may have come into contact with the lens. I think it’s a careful balance between looking after your investment and caring for the coatings, but also not risking damage from excessive cleaning. However, I always use a dust blower before and the morning after each session. ... I am also very strict about no mascara (for guests) during outreach. It can be very damaging for optics.

Same here too. The trick is to avoid using the same area of cloth twice and always swipe -lightly- from one direction to another (not moving in circles). This approach is safer for the lens coatings. I have also found that you really don’t need to use a lot of wonder fluid and always spray it onto the cloth, not the eyepiece. It is very effective stuff, but evaporates / wipes away far more effectively when used in smaller quantities.

Thank you, Don, for sharing all of this - it’s very generous of you. You mentioned your 20 point review in another thread and I have wondered what you include towards reaching such well-informed conclusions. 👍 In terms of the cars, I quite like the Jay Leno approach...why not have one of each!

That’s an interesting idea, Louis. At 20lbs, that’s quite some eyepieces case! My Peli case isn’t deep enough to support this option, but I also think I’m close to my comfortable weight limit. I can certainly feel the weight difference with it fully loaded up. Having just checked it on some scales, it is now up to 7.3kg (16lbs).

A quick update... Firstly, thank you all for sharing your insight with this. I ended up making the decision to close the gaps in my available focal lengths (expanding on the 21E, 13E, 8E and 6E quartet) and, in particular, have something else to complement the 21E for lower power / wide field views. Below is the updated case which now includes a 30mm XW and a 10mm XW. This will be my main case as it covers focal lengths from 30mm to 3mm. After spending some initial hours with the XW eyepieces, I have found them to be extremely comfortable and very easy to use in terms of eye placement. I will evaluate their optical performance over a series of nights and don’t want to jump to conclusions, but I have certainly been pleased with the views, so far. For the reasons of comfort and accessibility primarily (so that my son can enjoy higher power views too), I have decided to expand my higher magnification set and complement my 3-6mm Nagler zoom with the XWs. I’m starting to see why you enjoy using these eyepieces with your refractors, John. This arrived today. Can you see the emerging theme here... (another case might be required)😀 Ironically, my observing partner (who also reads through the posts on SGL) ended up purchasing your recommendation, Don, for the 30mm APM ultra flat. I had, regrettably, already ordered the 30mm XW before your recommendation. I will therefore look forward to a bit of a ‘shoot out’ between these two heavyweights: the 30mm XW and the 30mm ultra flat.

Assuming that everything is setup correctly with the focuser, it sounds like you might need more inward travel in order to bring the eyepiece/s into focus. Barlows require more inward travel than simply using the same eyepiece alone. It would be worthwhile sending MackTheNight a message about the ‘winning’ combination and how it was achieved. I suspect that it’s probably the result of a specific eyepiece, specific barlow and possibly a small modification to the focuser? I have not used the 130 explorer, but some of the other Sky Watcher newtonian scopes include a short extension tube. If this the case for your one too, you would -at present- be missing sufficient outward focus to bring the eyepiece into focus. I am purely speculating with this suggestion though. Can you achieve focus without using the barlow?

Have you had an opportunity to try out the barlow yet, Dale?

Wishing you clear skies in the Lake District so you can test out the scope and, I very much hope, enjoy the darker skies up there.

The resulting magnifications are calculated by taking the focal length of your telescope (900mm) and dividing it by the focal length of your eyepieces (e.g. 8mm) 900 / 8 = 112.5x magnification. When you add a 2x barlow into the optical path your 8mm will essentially function as a 4mm eyepiece (resulting in 225x magnification). On Newtonian designs, it’s best to keep the eyepiece in ‘mm’ more than the focal ratio of the telescope. Your telescope has a focal ratio of f5 so, in my option, the resulting 4mm of the 8mm + barlow is a bit too much magnification for your setup. My suggestions for four eyepiece focal lengths would be: 25mm (36x), 15mm to 13mm (60x to 69x), 10mm to 8mm (90x to 112x) and 6mm to 5mm (150x to 180x). These would also scale up well to a 200p in the future. You wouldn’t always want to use a barlow as it would limit your ability to enjoy wide field views. However, if you wish to use it as much as possible you should double the focal lengths suggested above (excluding the 25mm which should be used without the barlow). Therefore: 25mm (not used in the barlow), a 20mm (resulting in 10mm in the barlow) and a 12mm (resulting in 6mm in the barlow).

Your alternative one is the same one I shared before... which is positively reviewed on FLO (so should be ok?). The Baader one is a click lock type, but is also much taller and more expensive. The additional height may impact your ability to find the focus position of certain eyepieces. Both of these would still require an extension tube (different -shorter- length for the Baader) in order for your eyepieces to reach focus and any locking mechanism is not securing the eyepiece, just the extension tube. https://www.firstlightoptics.com/adapters/baader-2-clicklock-m54-clamp.html It’s also worth considering whether, with all the additional focuser parts, at what stage would it Be worth just upgrading to a different/better focuser? I have recently upgraded a focuser for a fellow astronomer and can confirm that it is fairly straightforward. Please see below:

Hello Stanga, Welcome to SGL. It sounds like you’ve had a really interesting journey - both through life and photography / astronomy. Clear skies. Rob

Hello Ecki, Welcome to SGL. That’s an extremely nice imaging rig you have there and what a beautiful location to use it from too. Wishing you clear skies. Rob

Depending on whether you intend to primarily mount a DSLR or (at some point in the future) a telescope, you should buy the best mount you can afford and manage. It is arguably the most important part. You will certainly want an equatorial mount for longer DSLR exposures. If your budget can stretch to an HEQ5 the payload increases from 7kg to 11kg for imaging.

Your SCT will be extremely difficult to achieve stable views from inside. At a magnification of 169x it will be particularly tricky. The temperature difference between the air inside the OTA and the air around it will result in thermal currents across the mirror. The air inside needs to match the temperature outside for really stable views. It is quite likely that your issues are, therefore, due to observing from inside and I would certainly recommend a star test from outside to check this. Perhaps the room had cooled right down during your previous success (although views would be greatly improved from outside)? If you are observing through a window the additional layers of glass, given their own thermal characteristics, will also affect views. If you observe with the window open, the air around the window will also affect the views as it, too, will have thermal currents where the colder air from outside meets the warmer air from inside as well as the heat radiating from the various indoor surfaces. All of these components result in thermal currents. It’s the same principle that impacts observing a planet/DSO which is located close to a roof / building is not ideal - the roof / building is radiating lots of heat which results in less stable views (even when you are observing from outside).

Is your telescope an 8” SCT (Schmidt cassegrain)? If so, they hold colimation pretty well and can -usually- cope with a light tap. Continuing this assumption, they provide a focal length of 2032mm so your 12mm eyepiece would be producing 169x magnification - This is certainly achievable on most nights. It is also possible the views might have been affected by thermal currents within the telescope. Whether it is a newtonian or SCT scope, it will require sufficient time to cool down to the ambient outside temperature. An SCT, due to its closed design, will take a little longer to cool. By comparison, newts tend to be a bit quicker. When I had a 9.25” SCT, I used to leave it outside for a minimum of 1.5 hours before considering any meaningful observing time. A Newtonian OTA should be good after about 45 minutes - depending on the temperature difference between where it was stored and that outside. Newtonian scopes are more susceptible to being knocked out of collimation and should, ideally, be checked each time to ensure the best views. A cheshire eyepiece is the most accurate, but a laser collimator is quicker (at least until you are comfortable with using a cheshire). However, if you have an SCT it is a little more complicated to collimate. This video explains how it works for SCTs: There is also quite a lot of focus travel on these scopes so it’s worth double checking that it isn’t just really out of focus. Point the scope to a star and keep focusing so that you are reducing the size of the ‘fuzzy blob’ - hopeful it will, eventually, cone into focus. ...Edited due to incorrect eyepiece focal length initially mentioned.

I believe that the threads are a metric size - M4 specifically. The Allen key required would, I assume, be a metric size too. A lot of people prefer to remove the ones supplied by Sky Watcher and replace them with a thumbscrew alternative. This means you can adjust the secondary mirror by hand, rather than requiring an Allen key... which you certainly don’t want to drop on the primary! here’s a link to a replacement thumbscrew set: https://www.365astronomy.com/set-of-m4-thumbscrews-for-secondary-mirror-collimation-45mm-long-set-of-3-screws.html

As your telescope has a focal ratio of f4 it might be less forgiving of certain eyepieces. In terms of of your budget: top end: Baader Morpheus 6.5mm (185x magnification) and 4.5mm (276x). https://www.firstlightoptics.com/baader-planetarium/baader-morpheus-76-degree-wide-field-eyepieces.html . The 6.5mm would be a good all rounder for all plenary and lunar observations; The 4.5mm would be useful for the moon and Mars and, perhaps, Saturn in really good seeing. As well as good optics, both of these eyepieces have a wider field of view (76 degrees) which can be useful for manual scopes. middle: Vixen SLV 9mm (133x) and 6mm (200x) have good eye relief, very good correction and are useful focal lengths. The 9mm has a 50 degrees FoV; the 6mm has 45 degrees. https://www.firstlightoptics.com/vixen-eyepieces/vixen-slv-eyepieces.html lower: 8mm (150x) and 5mm (240x) BST starguiders, Baader classic 6mm ortho (200x) or OVL Nirvana 7mm (171x) are all worth exploring. https://www.firstlightoptics.com/bst-starguider-eyepieces.html https://www.firstlightoptics.com/ovl-eyepieces/ovl-nirvana-es-uwa-82-ultrawide-eyepieces.html If you are prepared to ‘blow the budget‘, the 7mm (171x) Tele Vue Delite is one of the best planetary eyepieces I have experienced and is also very comfortable to use. https://www.firstlightoptics.com/tele-vue-eyepieces/tele-vue-delite-62-degree-eyepieces.html