Piero

Nice one! As we are in dobson mood, here are mine together: and my favourite pictures for both of them: And the babies here too: OOPS... basically all my telescopes are most loved ones!

Nowadays, I kind of regret selling my 20mm Lunt HDC, although I remember this was sold because my main dob at that time was a 12" f6 and I used to swap from the 30mm APM UFF to Docter 12.5mm (.. Stu's regret.. 🫣) all the time, skipping the 20mm. Now that my main dob is a 16" f4 + PC2, a 20mm XWA would be a nice tool. Having said that, I do have a N22T4 which pairs with the Docter 12.5mm better than the 20mm XWA in terms of ergonomics and AFOV. I regret selling my first N13T6 and N7T6, which were eventually bought again, so error fixed. I have kind of regrets about things I bought too. It was part of a learning curve, although quite expensive! It took me a while to realise that I like observing planets, double stars and the Moon more occasionally than consistently.... I would probably be as happy with a second hand 4" F9 SW as with a 4" f7.4 Tak, considering that I use this refractor for white light solar observing 95% of the time. I regret buying a few delos twice, doh! I kind of regret that I did not have the courage and confidence in building a telescope in the past. If so, I would not have bought my Lukehurst 12" f6. On the other (and positive) side of things, if I had not bought that telescope, I would not have explored telescope making at all.. Life is what it is... you live, you make choices and some of these are sub-optimal or just wrong. You learn from that. That's what experience is about in the end.

Same here. I have an 8", 12" and 16" reflectors - all sitting on a dob mount. The 8" is used from my mother's flat in Italy. I use a small table to raise this telescope about 300-350mm in order to see beyond the balcony fence. Classic alt-az mounts with tripod work well on small telescopes (e.g. refractors).

To be honest, with those two telescopes, it seems to me that what you miss is a low power eyepiece and neither the 19mm nor the 17.5mm really satisfy this need. I would look for a focal length of about 24mm which would give you exit pupils of 4.8mm (with 6" f5) and 3.2mm (with f7.5 refractor - larger exit pupil means lower magnification and you don't want to go too low with a small telescope). A 24mm focal length eyepiece is very versatile in a large number of telescopes, just in case you decide to replace yours in the future..

I didn't replace them, but just use my Zeiss zoom + VIP for high power. This combo doesn't reach 370x that the 2mm HR does with my tak, but realistically when I want that kind of power I prefer to use a larger telescope. Eyepieces are a complicated matter!

The three copies of HR I had were excellent and I found the HR design quite comfortable as far as ER concerns. However, 42 deg is still 42 deg and after years of use and comparisons, I found that I prefer eps with a larger fov. Therefore, I sold my 3.4mm, 2.4mm and 2.0mm with no regret.

Agree with the posts above. The mirror shouldn't be squeezed or locked by its supports. The original mirror cell of my 12" f6 dob (Lukehurst classic) did squeeze the mirror and caused severe astigmatism and spherical aberration. The telescope couldn't be used above 150x and it showed poor images below that threshold too. The back supports were also causing issues and the sling was incorrectly installed aside from being too much oversized. The horror above was replaced by a mirror cell I made based on Kriege's design and now those issues are all gone. The mirror cools down much faster too. The redesigned mirror cell above (3rd photo) was just assembled when the photo was taken. The Glatter' sling cable was shortened after the mirror was added to the cell. In the 4th photo the dark circular area above the mirror is the mirror lid which I leave it there when the telescope cools down due to cats in the area (and they love boxes..!). BTW the structure was redesigned too. 6-point mirror cells are easier to make and they work as well as a correctly implemented 9-point mirror cell. If you need more points, it's better to step up from 6 to 18, skipping 9 completely. Besides, a 6 can be transformed into an 18 if really needed. My 12" f6 mirror is quite thick (37mm) and I have no issue with 6 points.

Yes, you are correct: aperture and dark skies. I should have mentioned dark skies previously as they are both required to maximise the impact. I haven't ever tried an Ethos, but in terms of optical quality, I don't feel that the 9mm, 7mm and 4.88mm APM XWAs are significantly behind (or behind at all) the TV Delos I have. With my 16", I often use the 9mm (=2mm exit pupil) to search and observe targets. Depending on the target, I might then increase or decrease the magnification. For low power I use a 22NT4 which I feel comfortable for panoramic observing of large-ish targets. It is certainly not my most used eyepiece, but it has ergonomics similar to the docter (e.g. large e.r, 82-84 deg AFOV, size, height), so I find that the pair works well.

I remember you like your 10 bco a lot. The only other ortho I tried is the 5mm Fujiyama. That is a good eyepiece but yeah, I have found out that 42 deg is too much claustrophobic to my eye. My 5mm is in Italy now and it is part of a minimal eyepiece set used with my 8" skywatcher dob. I also sold the HRs and when I have more time, I will sell 3 delos too. Nowadays, I am fully happy with XWAs, naglers, docter, ZZ, UFF and a Pan.

Also worth mentioning that you have encoders in your 24".

In the past I used to pay quite a lot of attention (and money!) in order to go as much deep as possible changing eyepieces. It is an exercise which works up to a certain point, but in the end of the day, if you really want to go deeper, increasing aperture is a better way to go, in my opinion at least. I have a 4" Tak refractor and this gives exquisite images with the Docter or Zeiss zoom. My 8" skywatcher dobson (when collimated) with a 25mm Plossl beats it hands down as far as going deep concerns. My 12" f6 dobson shows stuff to another level and the 16" goes even beyond. Don't get me wrong, I like using high quality eyepieces. It's just that there are some very nice eyepieces out there today to make people happy without spending a fortune and the big difference is by jumping between apertures. Even though I don't have a 100 deg AFOV addiction, I must say that the 3 APM XWA I have work very well in my PC2-corrected 16" f4 dob and I find them more comfortable to use than the delos 8, 6 and 4.5mm I also have (and need to sell) in terms of finding and observing targets at +200x whilst minimising the nudging of the telescope.

I would not say "blows away". I have the 9, 7 and 4.88mm APM XWA and in my opinion they are great eyepieces. To my eye the 12.5mm Docter is a nearly perfect eyepiece on many criteria, but its cost is considerably high for most people. I found mine in the second hand market at a sensible price for my wallet. If I didn't have one and the only option would be to buy new, I would get the 13mm APM XWA instead. That's what I meant previously.

Sorry mate, but the only times my docter is allowed to leave the eyepiece case is to comfortably sit on my feathertouches..

I have a N13T6 (my second, lesson learnt!) and also had a 12mm Delos in the past. Optically the Delos is a touch clearer and for this reason possibly more suitable for planetary observation. It's a medium size eyepiece though and for that size I found that I want more FOV from an eyepiece. The Nagler T6 is a very powerful little tool which fits in my eyepiece pouch nicely. My Delos 12mm was sold as replaced by the docter 12.5mm. If I didn't have the docter, rather than getting a Delos 12 I would get for a 13mm apm xwa. Note: I don't observe with spectacles and I tend to observe DSOs mostly.

In my 4" f7.4 I like the set: 24 Pan, 13-9-7 Nagler T6. The 3 naglers are then barlowed with the baader qturret or VIP. They offer plenty of FOV and don't affect the balance of the telescope. Other times, I use the set: 30mm, Zeiss zoom +/- VIP Barlow. That's my 2" set for that telescope. It's largely used when I feel lazy or for observing planets and the Sun.

It contains a rich amount of tabular data. Descriptions are minimalistic and I agree that it works best when combined with the atlas rather than standalone. It's a great guide.

If it helps, here is the album for the design and construction of my 16": https://photos.app.goo.gl/DAZ8CqeRtJGe83jF8 That was my first wood / metal work.

My 12" was designed by Lukehurst. The original mirror and rocker boxes were quite tall and in my opinion the rocker was not particularly sturdy although it worked. I updated it quite a lot last year and now it's much sturdier, lighter, more portable, but most importantly more predictable in terms of performance particularly due to the new mirror cell. Here's a summary of the changes.

The rockerbox of my 12" f6 has a thickness of 3/4”. It works but I think it is better now after decreasing the centre of gravity. In my 16" f4 the boards have these thicknesses: bottom: 1", sides: 30mm, front/back: 15mm. I used dowel joints for the RB. Personally, I'd go for 3/4” for a 10" and then cut off wood without affecting sturdiness.

Nice one, Stu! With the right conditions, those toys can be jaw breaking!

Nice telescope, congratulations! Btw there isn't a right / wrong side of the focuser. Personally, I much prefer the focuser installed to the right when the telescope point to the south (like on your photo). In the north hemisphere, this means that the telescope is pulled towards the observer - which is a safety bonus if a ladder or step is used. If one is left eye dominant, it can also be easier to switch between focuser and finder. I fitted the focuser to the right side in both my 16" and 12" dobs for these reasons.

I can satisfy your request Sir! Here are the Google Photos albums. They show the building process from the most recent to the oldest photo: 16 f/4 "Nunki" : https://photos.app.goo.gl/DAZ8CqeRtJGe83jF8 12 f/6 "Phoenix" : https://photos.app.goo.gl/qPdsWRQUiqxmm9ec9 Astro chair : https://photos.app.goo.gl/fxsWy3e5BVfkKWM9A

Thanks Dave That's a good question actually! The chair was designed taller than necessary, so that a child with adult supervision can sit and observe. With the 16" f4 dob, an adult would sit at about half height when the telescope points to the zenith. With the 12" f6, the seat needs to be placed higher but I generally stand when observing with that dobson. In conclusion, yes, for an adult, the chair is taller than necessary. It is comfortable for the back though.

Thank you. The second dob was finished with Ronseal yacht varnish. I finished the chair with Smith's CPES and Ronseal polyurethane. The finish was pretty and a bit easier to work with, so I applied it to the first dob too one year later.

Thank you 🙂 That's correct, the second dob and the chair were built from scratch. The first dob is a substantial redesign of a Lukehurst dob. Here's a summary of the changes side by side. Not sure how noticeable is, but the mirror box is quite shallow too now (15").