Piero

It's possible that the myriad is a bit heavier. Ernest measured 854g (see link above).

My first 100s was a Lunt Engineering HDC. I liked it but was not hooked. At that time I used it with my 12" F6 dob and usually jumped from 30mm to 12.5mm. I have eventually been hooked by 100 deg eps after trying the 9mm and then 7mm APM XWAs. The scope this time is a 16" F4 + PC2 and a focal length of 9mm really feels optimised with this telescope. I decided to swap my N22T4 with Steve's APM XWA 20mm to have a "matching set". Glad this exchange happened! So for me the "dyslexic duos" are: 30, 12.5mm with the 12" F6 dob and 20, 9mm with this other dob.

Mm.. to me they seem very similar in weight and I'm sensitive to this in fact I don't like heavy eyepieces. According to Ernest, the APM XWA 20mm weighs 689g (page to scroll: https://astro--talks-ru.translate.goog/forum/viewtopic.php?f=32&t=1445&sid=62f5b3f4a78b02a2dc07dc7c8da24868&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp&_x_tr_sch=http ). I just measured it too and got 695g. Is it possible that you didn't subtract the tare? @Littleguy80 FYI.

Okay, my main sets are: 1. rigid case: 4 X 2" eps + barlow 2. lowepro case: 3 X 2" eps 3. Pouch: 6 X 1.25" eps + Barlow I also have 3 Delos that I need to sell. In the pouch I have 2 other eyepieces which are kept for convenience but could also be sold. Rigid case and Lowepro case are used together in the field, so that I don't need to put eyepieces in my pockets. The selection of these depends on the telescope used. In Italy I have 3 eyepieces (stock plossls and 1 ortho) + Barlow.

Well done! It looks better than the original 👍

No, I have not. The mirror box of my 16" is only 11" deep. My 12" has a slightly deeper MB, but this has holes to the front and back at the level of the mirror surface (not the mirror edge!) to provide passive ventilation. Both mirror cells are based on Kriege's design, so the back is fully open. In either cases, the views become noticeable better (easily an extra 100x and more) as the light shroud is pulled about 3" up. --- Update: Here is a photo for the passive ventilation with the Kriege MC in my 12" F6. The mirror. Has it's lid (see dark circle). The counterweight balancing system has changed since this photo. My 16" is shown in my profile photo.

In my truss dobsons I pull up the light shroud about 3" from the mirror box. I find this to eliminate the formation of air boundary layer above the primary mirror as this cools down to ambient temperature. I also leave the fan behind the back of the primary mirror on, but at reduced speed. It's quite interesting to notice how much "poor seeing" is actually very local.

I observed a few galaxies in Leo last Saturday. I quite like the area around the "neck". If I remember correctly, stellarium calls them Leo quadruplet. Thanks @John for sharing that article. Like the author, my sky is bortle 4 and we use similar apertures. The sky was very steady. M3 was superb at 494x with my 16" dob. There wasn't a significant image break down at 714x either. Shame that the sky became foggy around midnight.

I agree with all what Stu said above. @Flame Nebula I certainly don't want to put you off, but have you already had some experience in imaging with your 80mm refractor? Reading your posts I suspect that you don't. Of course there is nothing wrong with this, but if this is the case, I would advise to approach this gradually. Imaging is a hobby in the hobby. Everyone in this forum appreciates astro images, but that's only the final result or the tip of the iceberg. Behind that there is a lot of effort, often long hours taking shots, processing, etc. Some people love all of this, others don't. Moving around an AZ6 is doable but I would not say that it is effortless.. and that's only one bit of the required equipment. What I am trying to say is to give it a go with a simple and cheap equipment to understand whether this is really your thing. Like you I was also interested in imaging when I came back to this hobby again, about 10 years ago. I researched half the Internet at that time regarding the equipment required for DSOs or planetary imaging. I decided not to press the button (and have no regrets about this) after mentally putting myself in the context of doing imaging. For instance, I work with computers all day and there is no way that I want to spend my free time processing data in front of a screen. I don't even like the idea of spending "at least" 30 min setting all up and then sitting on a chair watching and controlling my equipment in the dark whilst a lovely sky is above me. Let's not even mention the clouds coming and obscuring the target. I admire people pursuing this "other" hobby with pleasure. For me something like that is enjoyable as a job (e.g. as a way to get data for research), not as a hobby. As I said above, I really don't want to put you off. My advice is just to take it gradually, incrementing your knowledge and experience with time, and understanding whether you like it or not. To be honest with you, the same advice is also well applicable to visual observing and that's at least one order of magnitude simpler than imaging. Hope this helps. Piero

If wheelbarrow handles are fitted, moving the telescope around is not tiring at all. I leave my 16" f4 assembled in the garage and wheel it out in a couple of minutes. Seriously, it takes me less time to observe with this telescope than my 4" refractor.. This photo was taken from my previous house. The telescope lived in the living room and was wheeled through that door and steps with ramps. From that door I wheeled it for about 20m (each way). Your TV eyepieces with a coma corrector will work fine.

Looks very good! Enjoy your new focuser!

I reached the same conclusion with binoculars.. My eight eye is not as good as my left one and thankfully I'm "lefty" (..like Al Pacino in Donnie Brasco) .

I had the 5mm and 9mm Vixen SLV and thought they were very good, particularly the 5mm. In my opinion though, it is a bit unfortunate that although good they don't exceed in any particular feature apart from eye relief. The Vixen HR are better optically, and a lot of other eyepieces are much better in terms of AFOV. Eye relief helps, but one needs to be seriously astigmatic to need 20mm eye relief below 10mm focal length, particularly with 50 deg AFOV... The SLV would have been a boom if they had come out a decade earlier at least, I feel. In that case they would have won against TV plossls.

I am not an imager. As far as I know optical aberrations and distortions appear very clear in imaging. Therefore, I am not convinced that you can get away without a coma corrector. Aside from this, it is a question of image scale and magnification. Following that, one needs to get a mount which tracks in a very robust manner. Therefore, due to its long focal length, I think an SCT seems more suitable for planetary imaging, whereas a Newtonian could be more suitable for imaging larger objects requiring less magnification. It would be good to have feedback from imagers.

Why don't you want to use the 12" with a Dobson mount? To me that's the way to go, unless you want to do imaging on specific targets. Even so, you are likely better off with a smaller aperture. At f4, you will need an adjustable chair and a coma corrector. At f5.3 you might want to add the former, but not necessarily the latter. 12" is a good all-around aperture for visual astronomy. Personally I wouldn't go with OO due to their customer service. Any chance you can build your own dobson? Building my 16" has been one of the greatest pleasures of my life and I started from knowing nothing (not even used a drill..). If you decide to build one, I strongly recommend to get a copy of the dobsonian telescope by kriege. It gives some great insights but most importantly it teaches that everyone can build a telescope with some dedication. Just a thought of course.

Some long lists above! I must admit I only sold one telescope: a Lunt Ha 50mm. It was sold as I was not happy with the aperture. That's all!

What @Spile said above. Regarding the frequency, it really depends on how dirty it gets. Also note that on this forum there is a widespread phobia about cleaning telescope optics. On Cloudynights, the "finger procedure" is mentioned several times and members are quite comfortable with it. My advice is to learn how to do it, always be gentle making sure the surface is wet, and don't be afraid of doing it when it is needed. A bit of dust won't hurt, a pile of accumulated dirt as I have seen on some photos posted by a few SGL members who said that you should never clean it, in my opinion, does hurt. Also remember that whilst dust is not necessarily bad and it can also be blown away with a manual blower, air chemicals, pollen, fungi etc are bad for the coatings. The mirrors of my truss dobsons get cleaned every 2-3 years as our weather does not allow me to use them very frequently. They are also truss telescopes so the mirrors are more exposed. It can be less frequent in a close tube dobson, but again, a lot depends on how dirty it gets. Edit: if you use FLO guidelines, personally, I would use distilled water for the whole process (no tap water at all).

I forgot to add some photos related to the focuser replacement. The reason is that I wanted to use my 2" eyepieces and these reach focus at very different positions. The Antares helical focuser was quite uncomfortable for this and so I decided to replace it with a Kineoptics HC-2 focuser. The UTA no longer fits into the mirror box, but I have never really care of this detail, actually I found it a bit clumsy. The focuser base is home made by me using a basic aluminium square. As the new focuser is a bit higher, the poles had to be trimmed. Before trimming the poles: After trimming the poles: Finally, two stainless steel metal rods wrapped with black shrinking material are now used as a counterweight. These can be added or removed very quickly, but most importantly they keep the mirror box shallow and light.

Hi Flame Nebula, To give you some context, I bought a 12" f6 dob which revealed to have several issues. It took a steep leaning curve to understand and fix them. Following that I kind of lost interest in that telescope as I wanted other things built differently. Therefore I decided to design and built my 16" f4 exactly how I wanted. This was the first telescope I built - so another steep learning curve. Following this, the 12" f6 was redesigned. The story about this 12" f6 dobson is described here: The redesign is at the end of that thread, but if you find it interesting, you might want to go through all. I tried to be as analytical as possible in order to help other members. By the way, you reminded me that I forgot to post some photos of the new focuser I fitted last year. Will do on that thread later.

This thread makes it clear that many of us could open an astro shop! Be careful FLO!!

Ouch, that's a tricky question...! 😰 It would possibly be my redesigned 12" f6 dobson, but just because it can be loaded on my car rather easily, so it is more versatile in terms of transportation. If this were my only telescope, I would fit it with wheelbarrow handles so that it can be stored assembled in my garage and simply wheeled outside when in use. It is a tricky question though because I am very fond of my 16" f4 dobson (it was entirely built by me) and this telescope has an edge on my favourite targets (galaxies and PNs). Also, if I had a larger car or a minivan, I would likely choose the 16" f4.. My 16" f4 was conceived as a replacement of my 12" f6. The latter did not sell in the second market despite of being advertised for less than 40% its original price. After heavily redesigning it, I became fond of this 12" f6 too. 🥰 How can you choose between two children?! 😭

I have 4 telescopes: - TV-60 f/6: this was bought in 2014 and was my only telescope at that time. Nowadays it is used when I walk or cycle to the countryside under darker skies or when travelling. I use it on large targets with some zoom ins. - Tak FC-100FT (feathertouched ) : this was bought in 2017. It is used for solar observing, planets and scanning the milky way. Somehow, this is my least used telescope, likely because I am not into double star observing and I rarely observe planets these days. My main reason for keeping it is solar observing really as the TV-60 is too limited on this. - 12" f/6 truss dob: this was made by Lukehurst in 2019 and was redesigned quite brutally by me two years later. It is generally taken to the countryside under darker skies. It is stored disassembled in my garage, so it can be loaded in the car very quickly. Before redesigning it, my plan was to sell it. Now it has its use case and I am very pleased with its new structure. - 16" f/4 truss dob + PC2: this was built by me in 2020-2021 and is used at home (which by the way is in a village in the countryside). It is stored fully assembled in my garage, so it can be wheeled outside very quickly. This is my most used telescope. It is used on the targets that really trill me: galaxies and planetary nebulae. 16" f/4 is a great size for me and do not plan to get anything larger as I would need an observatory somewhere. It can be fitted into my car, but this is not really practical and I don't want to risk injuries. In my opinion to carry a telescope like this or larger, one would need a pickup, a minivan or a stationwagon so that the ramps can be carried too with easy. As none of these vehicle is needed for my work and I want to limit my gas emissions, these are out of question. The redesigned 12" f/6 can be loaded easily and the weight of each component is well acceptable. No ramps are needed here. 12" is a good aperture anyway, particularly under dark skies.

Andromeda is about 6 full moons. I had the best view of this galaxy with revelation 15x70 binoculars (£50) from the Devon countryside.. Larger dobsons tend to have a longer focal length and therefore higher magnification and smaller field of view. They allow one to see smaller and dimmer targets. Globs, small open clusters, the vast majority of galaxies (not the big ones close to us), planetary nebulae, details in extended galaxies etc.. With larger dobs you might want to spot the brightest globular clusters in Andromeda... Eventually what matters the most is the darkness of your skies. Of course, dark skies+aperture=heaven..

Having already a 8", I would also go for the 4" refractor. This will also show a larger FOV at low power compared to the 125mm. Adding the fact that you buy it second hand at a very fair price, to me the choice ia quite obvious!

Personally, I am not a fan of Tak focusers (even after tweaks) and my MEF-3 was sold as I didn't like that either! When building my 16" f4 dob, I ordered an FT focuser with a drawtube 2" long, whereas the 1.5" version was actually more suitable as this telescope is used with a paracorr2 (therefore the drawtube length is less relevant and the 1.5" model allows me to screw nebula filters directly onto the base of the coma corrector). To cut the story short, I was lucky enough that an FT focuser with 1.5" drawtube came up in the second hand market (thanks @Stu). Therefore, the 1.5" model was fitted on my dob and the 2" model was fitted on my tak fc100 (before DF, now FC 😎). A short extension tube is needed with the tak but this is not a big deal. The difference in use is striking to me. Never looked back, no remorse.