Piero

Quick heads-up! The seeing is incredibly steady right now over here and Jupiter looks superb with a very distinct hollow surrounding the GRS and plenty of details on the belts. The GRS is also showing some rounded features. One moon (not yet checked out - could be Io) has just started its transit. Typing while observing.. 🙂 Telescope: 4" Tak; eyepiece: Zeiss zoom 25.1-6.7mm + VIP barlow operating at about 200-220x

Congratulations Stu! That's a great move! Working from offers some new opportunities.

Wow! Excellent progress and in general fantastic images. The image of Venus is one of the most beautiful I've seen (as taken by an amateur).

Excellent work! 🙂 Looks very neat!

I think you can use lower mag due to the darkness of your skies. Under my skies, I am not sure there is enough contrast to temporarily spot it under 300x, but I might be wrong. How does the nearby faint IC 1296 look like over there? (Apparent "nearby" - that barred spiral galaxy is 256Mly distant from us, compared to the 'just' 2Kly of M57). Although there seemed to be something small and fuzzy where that object is located, I would not bet on it as it could have just been a faint star rather than the core.

I compared my Baader Morpheus 9mm against a Nagler T6 9mm and Delos 8mm using my 16" F4 reflector + PC2. In my opinion: - the BM9 is as immersive as the N9 - the BM9 is more comfortable, although without spectacles, I find the T6 naglers quite comfortable.. - on-axial sharpness / contrast seem identical to me. I would say they go deep in a very similar way - off-axial sharpness / contrast, the Nagler is better (from 50% of the fov). In particular, the BM9 shows some astigmatism (nothing terrible, but noticeable). Stars are consistently tight in the Nagler across the whole FOV - colour rendition... well, to me the Nagler is more engaging here, as stars seem more colourful and vibrant. - field curvature: none of them showed FC to my eye, but 1) the focal length of my 16" +PC2 is 1870mm, 2) my observing eye is only 38 years old - chromatic aberrations: to my eye none was visible The Delos 8 is sharper and goes a bit deeper than both and colour rendition is excellent to me. I am not a great fan of their eye cup sliding mechanism, but maybe it's just me being a drama-queen . My favourite eye cup design is like the Docter or APM UFF 30mm, but I'm also fine with the Vixen SLV style. Oh well, I guess I will need to adapt and get used to it. I haven't tried he Nagler T6 9mm with the VIP barlow, but I did with the BM 9. With the latter, I have not seen an appreciable improvement which instead I've consistently seen when the VIP is added to other eyepieces (e.g. Zeiss zoom 20-75x, Nikon zoom, Vixen SLV, Delos). It was as if the VIP barlow was out of the way and the eyepiece showed a magnified field. With the other eyepieces, the VIP tends to make stars tighter, sharpening the views.. I still remember that time when I VIP barlowed my Vixen SLV 5mm and compared against the Vixen HR 2.4mm on my TV-60 observing Jupiter.. The barlowed SLV was just a tad behind, but really not much at all. At ~150x, both eyepieces showed far more detail (sharp detail) than the Nagler T6 3.5mm at ~100x. That was probably the most beautiful observation I had of that planet with that small telescope. Also the Delos responds well with the VIP. In summary, I agree with Don that the BM works very well up to probably f/4.5 - 4.7 . Above that, they are real bargain eyepieces. Below that, one might start thinking about other options if the desire is to have a highly and consistently corrected FOV.

Similar here.. With my scope and observing style, I never felt the need for a 18-16mm eyepiece. I tend to skip that range even with my zoom eyepiece.

Last night I was out with my 16" f4 + PC2. Most of the time was spent on Cygnus and M56 in Lyra, although M57 near the zenith is difficult to ignore. This planetary nebula looks beautiful in this telescope. This time I was not interested in its nebulosity, but in the white dwarf at its centre. This star is estimated between 15 and 15.2 mag, but the main difficulty is the presence of the gas surrounding the nebula. To decrease the apparent surface brightness of the nebula and increase the brightness of the star, high magnification is required. My Delos 6mm gives 311x. Although at this magnification a lot of dim stars become kind of more visible, after spending time observing it was clear that the gas of planetary nebula was still too bright. Therefore, I added my modded Baader VIP barlow (1.83x) and used first my Delos 8mm (427x) and then the Delos 6mm (570x). Using either these two eyepieces, I managed to detect a faint glimpse of the central star. It was not easy though. First of all, I needed to use an eye patch on my other eye to relax my observing eye. Secondly, my observing eye had to be dark adapted. This meant to continue observing the nebula for a few minutes constantly, wearing an observing hood. Although I spotted the central star in direct vision, I used to slowly rotate my eye around the nebula ring to help the eye rods. The central star is elusive. It was not visible all the time, but its visibility is heavily seeing-dependent. For instance, it was literally invisible, then it popped up for 1-2 second very faintly, and then it disappeared from my eye. I managed to see it three times last night: two times with the Delos 8 + VIP, 1 time with Delos 6 + VIP. It is also quite interesting to see how the M57 surrounding landscape gets populated by stars as the magnification increases. Once indoors, I did some research and found this image compiled by Brian Skiff (Lowell Observatory) showing the nearby faint stars and their magnitude: Here is an amazing video about M57: https://youtu.be/6FSIfUYFeTM

That's correct. A 25mm diameter half-round bit matching the 25mm diameter solid oak rods used for the seat and footrest.

That's lovely!

You built a very fine chair. Nice design! 🙂 Although I haven't measured mine after applying the finish, the total weight is about 9kg. I don't mind this weight as long as it is stable and comfortable. There are times when I also use it indoors for other reasons. The seats can be removed any way.

Thank you, sir! 🙂 I often think that all started from here:

Thank you very much! 🙂 It has been a very nice experience. The telescope, bookcase, and observing chair are my first wood (and metal if we consider the dobson mirror cell) projects. The holes on the mirror cells were my first holes with a drill. Yeah, a steep learning curve as one has to study the physics of good designs, telescope making, but also how to use those tools. In my case those three projects were done with a drill, jigsaw, a router (both fix and plunge base), and a random orbital sander. I bought the latter half way through as I was getting bored at sanding, really. It helped me quite a lot though.

After gluing the two panels together, I cut the horizontal slots with my router using a plunge base. It wasn't difficult, only a bit repetitive.

I use a Tracer 12V 7Ah LiFePO4 Battery ( https://www.tracerpower.com/tracer-12v-7ah-lifepo4-battery-2.html ) to power a 4 channel controller which regulates the mirror fan and 3 dew heaters (Rigel finder, astrosystems secondary mirror, 2" ep which I actually use for the RACI finder). The battery is light and small. It fits in the rocker box of my 16" without any issue. I charge it two times per year, because it is advisable, rather than because it runs out. It's a great device in my opinion. I want to get a cable to power USB devices too, but always forget..

@popeye85 30 ES 82 or Nagler 31 ("the terminagler") are big and heavy beasts. It might be fine with you, but something to take in consideration. I personally prefer eyepieces of about 500g.

Mm.. although what you say is correct, in practice an F4 newtonian requires a coma corrector. With the TV paracorr 2, the F4 becomes an F4.6, and the 30mm eyepiece delivers 6.5mm exit pupil. My eyes are not old and can definitely handle that exit pupil. My 30mm APM UFF gives wonderful views with my F4 dob + PC2. This works particularly well with OIII or NPB filters when observing extended nebulae. In an F4, a 20-22mm eyepiece is also well suited and more general purpose. The 30mm is more of a dedicated eyepiece or when one wants a larger fov. It certainly has its use case though.

Will do, but not regularly. For the time being I want to spend more time studying the objects visually at the eyepiece, rather than taking notes.

Thanks Stu 🙂 Yeah, I completed the 16" in April. It took 10 months of work. It was a great experience to design and make it I have to say. Now, it's a joy to use it. 🙂 I didn't write a thread about it because I wanted to avoid distractions. If you are interested, you can see the whole development on this Google photo album here: https://photos.app.goo.gl/DAZ8CqeRtJGe83jF8 It's an hybrid design really, with ideas from many telescope makers. The primary mirror is a 16" f4, figured by John Lightholder. He kindly sent me videos about his work on it. You can see them in the album above. The secondary is a 3.5" Antares, supported by an Astrosystems heavy duty spider and holder.

Thanks guys! 🙂 Here's a photo of my "astro" bookcase mentioned in my first post. Same plywood. Dado joints for the shelves, doweling joints for connecting the outer structure. The 4 feet are the larger cutouts holes of my dob trunnions. Clear lacquer was used for finishing the bookcase. Need to study more..

And here some selected photos from the album:

I recently completed my adjustable chair. This will be used with Nunki - my 16" reflector, but also with the 4" refractor. The design was taken from the Catsperch PRO (stunning astro chair in my opinion) with simplifications taken from the Denver adjustable chair. I didn't have solid oak hardwood, so I used Baltic birch wood instead. I cut a large panel (1" thick) in sections. Four of them were used for making a bookcase - which is now hosting my astronomy books -, whereas two of them were cut in half, glued and used for making the main body of this chair. The seat and footrest were made from cutouts of the rocker bottom board and ground board of Nunki. Hardware is aluminium 6082T and 316 stainless steel. The feet rest on 5mm thick heavy duty rubber material glued to the wood. 2 coats of Smith's CPES (the latter used as primer for the varnish) and 3 coats of polyurethane varnish were applied. I already used a few times now and it works very well for my weight in my opinion. Here's the album containing all the photos: https://photos.app.goo.gl/fxsWy3e5BVfkKWM9A

I've read very positive comments about the 22 Nagler. 🙂 Same about the 21 Ethos.. okay my comment doesn't really help.! 🙄 --- update More sensible comment. I would use the 13E and see whether the 100 Deg experience is really pleasant before taking a decision. I never looked through an Ethos, but I did have a 20mm Lunt 100 HDC. Excellent eyepiece, really, but it helped me realise that 100 deg eps are not for me. Other members love them. Life can be difficult with eyepieces...

New telescope leads to some eyepiece changes.. This is my first change in a few years... Delos 8 and 6 come in to play with the docter and VIP barlow on the F4 Newtonian. Zeiss zoom stays with me but will be used exclusively with the 4" refractor so that I don't need to swap eyepieces frequently.

Telescope waiting outside together with my observing chair completed only recently.