BGazing

Once you figure out which Tak you want let us spend your money on accessories.

Seeing is critical.

What's the budget?

Borgs are ultraportable and break down, if you can track a 90FL second hand you will have a winner. They are f 5.6 so not as stellar on high magnification like Taks.

You cannot go wrong with a Tak, if you can afford it, that is. 100DF is awesome, and transportable in a car on vacation (did it several times) but not really for airplane. Tak has a 76mm scope which you can break down in pieces for airline transport.

I am NEVER too tired to take a peek through my 100mm and I am never tired to lug my Borg 71 through airport hassle. YMMV.

Okay, managed two first lights, not at my dark place, but reasonable 20.61 SQM backyard, just to get a hang of the scope. 0 degrees C tests one's patience, and humid conditions are good for figuring out how it will behave under stress.

First, I've contacted Michael re wood chip, he was kind enough to offer to ship it all back so he can make the new cradle (he needed all the parts) but I'll just repair it. He'll ship some novelty of his, truss pole stabilizers. Will post a photo once I receive them.

In the meantime, I was stupid enough to mess with collimating triangle and managed to attach it wrongly. Then peeled it off, attached a new one. Some glue around the triangle and the triangle is again a tiny bit off, perhaps by less than a milimeter vis-a-vis center spot. Gotta say triangle is of immense help when collimating and adjusting in the dark. Not sure how much of a problem that slight off-centering is. I am going to let it be for now, but tips on how to remove it without to having to wash the mirror and whatnot are appreciated. 

Secondary attachment is so far my biggest peeve because it needs twisting around before starting to hit laser near the center of the primary. On the second night I managed to leave fingerprints on the edge of the secondary. So tips on cleaning secondary are also appreciated. 😂

My second biggest peeve is secondary ring attaching. I feel like I am always fighting it a bit, and RDF in the way is not making me like it more. RDF is under review, will see whether it is possible to mount some quick-release shoe and slot in Baader Skysurfer III because RDF needs adjustment after every collimation and doing it in the dark with the Allen key is not really fun. Also Baader has more clearance.

Scope is smooth and works the biz. It is not super stable, so needs to be handled gently. It tracks well and is buttery but if you swing it quickly (as I did) it might jerk and lose collimation. On the second night I had the feeling that it lost collimation once without me being able to pinpoint why. Also, as you might expect, if you collimate at 60 degrees it will not be the same story at 20 degrees and the laser will show it...but that is, again, not surprising.  Here, any tips from the owners are appreciated, but I guess those are the limits of the design.

Fans are silent (three of them, unlike GuLinuxes) and one can observe while running them (no vibration and low to medium powers). Seeing was not that great the second night, so I tried some low power targets (M42, duh, M48, Beehive, Pleiades, Double Cluster, M38, Thor's Helmet). Given that I do my DSO observing normally under much darker skies I cannot easily compare (e.g. Thor's Helmet with OIII is MUCH better in SCT8 at 21.40 than in a 12 incher under 20.60 sky). Of course all of the above are nice in a 12 inch scope. There's some coma, I am still learning to discern coma, collimation, heat plumes and astigmatism of the eye. Work in progress, but not too different from SCT (except for upside down effects of the heat plumes). It was fun, cannot wait to test it at my favorite site, although I feel the biggest problem there will be finding some proper flat piece of ground.

There are currently two threads on Alkaid 12, the other is mostly about various mods (here), so I will chime in in this one.

My Alkaid 12 has just arrived. F5, Quartz mirror. So some impressions...after just one assembly in my study. No first light yet, sorry, weather is terrible.

It really is compact, unbelievably compact and clever. Perfect portable little godzilla. Assembling it, I feel, will be snappy once I get a hang of it, disassembling is unbelievably fast.

Its stable and smooth. Compared to what? Compared to SW flextube 12s (two of them) which I perused, it feels actually solid with considerably less flexion. Not to mention the wonderful Moonlite focuser. I inserted laser, roughly centered it on the primary, moved it around...nothing, nothing moves. Perhaps I am doing something wrong :). Paragon 40 causes no balance problems. Will revisit this matter once Paracorr arives. 

Truss tubes feel like you have to 'find' the proper pairing. Some combinations look not so straight. I could be wrong...but the are sufficiently rigid, I feel.

Unlike the photos on the website, there are actually three primary cooling fans. Neat.

Mounting secondary ring is my biggest peeve, feels like RDF is too close to one of the 'slots'. 'Its not a bug, it's a feature', I guess. But I do not like it.

Secondary heater and its packing is really neat. Secondary mounting takes some time to figure out, but once you do it, it is okay. Packing secondary (exposed) gives me jitters, my cassegrain heart fears for exposed mirror surfaces.

One of the pins which holds secondary ring when packing was, it seems, drilled too close to the edge and the wood is chipping, pic attached. Was told by my friends that I should not panic because wood looks durable. The thing is, once the pin falls out packing it would be much tougher.

As @GuLinux mentioned, packing has to be seen to be believed, lots of small styrofoam flakes that float around and attach to pretty much everything. Had to vacuum them to cover my crime before my wife arrives. (You see, I have not bought a new scope, it is just a little wooden suitcase).

Thank you, Bill, for this extensive review. Excellent read. Very encouraging to hear that it is handling 2kg of binoviewers with EPs without seeming to lose colimation.

Don't know how heavy is that Argo Navis but I guess when velcroed to the carrying handle it acts as a sort of counterweight, too. 

Can't wait to receive mine, hopefully the galaxy season won't be a complete washout.

Would it also have to do something with bino light rays coming out polarized?

Your scopes are somewhat limited at how far you want to push their magnification. Achromat will show color and those little newts with spherical primaries peter out over 150x.

I'd reccomend something around 4mm at most. Those scopes are not taking high magnification that well, IMO.

On 07/09/2019 at 10:35, Brutha said:

Hi All,

I've had a Skywatcher Mak127 for a few years, and have enjoyed what I've seen through it (had less opportunity than I would have liked though!).

But will hopefully get a bit more chance this year for various reasons, so I'm thinking of upgrading; the Mak is quite nice, but the goto is a bit fiddly (I use the wifi dongle to connect), and the scope is also pretty much designed for planets. I'd like to get something that will give a bit more deep sky stuff, but be pretty much as convenient as the Mak, meaning I can carry it in and outside easily.

From a bit of reading around it sounds like the Celestron Nexstar 8SE might fit the bill, it seems to get pretty good reviews. It seems to be around £1300 new these days in the UK.

Are there any other similar options that people would suggest?

Thanks!

Brutha

I did just that...127 Mak to C8 and it makes sense, really. C8 is jack of all trades and will give you a lot of good views under dark skies.

Well, this hobby makes you learn more about weather than about astronomy.

Basically no weather is good for us, its either too cold or too hot or there is wind or no wind and high humidity. If by any chance it all comes together and it's perfect turns out I cannot go because of the commitments.

But hey, this year I bagged 4 new moons at the dark site and I consider that a massive success before snows cut it off from our reach. Just came back today...we went for two days and the forecast was okayish for the first night and meh for the second night. One guy cancelled because he was rational. The irrational part of the group went and enjoyed two clear nights. The second one was high humidity, but still. 

I guess this makes it even for the night when I went and the forecast was clear...and we ended up under 100 percent overcast sky.

6mm would be very useful in your scope. 5mm T6 is my favourite Jupiter EP in 7.4 100mm Tak, and 4mm is probably the most comfortable on the Moon. If the seeing allows I would go to 3.5mm or even 3mm on the Moon, but Jupiter gets washed out. So, based on my experience, 6mm would be great for your 8.8.

One more thing. With planets so low here (and especially for you up there), I consider ZWO ADC indispensable in my Tak for planetary. Cleans it up very well and you get to enjoy the views instead of some rainbow boil near the horizon. The trick is, you would have to use some barlow before the ADC to make your f longer (I use 2.5 PM) so you get to use longer fl eyepiece as your planetary. Eg. my 13mm T6 becomes 'Jupiter EP'. 

So...in your scope I would have both 5mm and 6mm and the ADC. But that's me.  My EPs are multiplying like rabbits.

Skiing pants are fine. Wool layer underneath. Basically, when you dress for prolonged sitting, you dress as if it were 15 degrees C colder than it actually is.

Congrats on your new scope, I have only now stumbled upon this thread. Seems like we caught the dob fever in succession.

It also looks like you held off Paracorr, which makes sense given the f/6 mirror. Just don't borrow one, you might like the look, I was told.

I see that you are observing planets, and they happen to be quite low at the moment. I found dispersion to be objectionable to the point that I could not enjoy the views with planets so low without the ZWO ADC. Effects of dispersion get progressively worse with aperture, it is always present, at 100mm at my latitude the views with or without are night and day, SCT 8 the difference is astonishing. I compared C8 with ADC with 12 inch dob without and it was a no-contest. I would say that even a 100mm refractor with ADC would show more than a big dob under effects of massive dispersion. ADC even makes seeing look better because it cleans up the smear.

So to enjoy planets in the coming years to the best extent, Jove and Saturn in particular, I suggest getting ZWO ADC. Its use is a bit more tricky with a dob (see online tutorial on lining up with the horizon), and you would have to use a 2.5 powermate to bring your f number higher and avoid astigmatism. But trust me, you need it for such massive aperture with planets so low. Just make sure to have 1.25 eyepiece in 2.5x more focal length than you would otherwise have...(e.g. in my Tak DF I use PM 2.5, ADC then 13mm instead of the usual 5mm for Jupiter). You may use it for your Tak as well, although you might need to buy additional EP or two...

Does anyone have any ideas where TS sources its quartz mirrors? GSO quartz mirrors (one, to be precise) did really well in a double-pass test of Tommy Nawratil and Wolfgang Rohr.

28 minutes ago, Piero said:

Regarding your question about collimators, I use the 2" Glatter laser with 1mm aperture stop and 2" Glatter tuBlug for adjusting the focuser and primary axial alignments. I prefer the Catseye Telecat XL for centering the secondary mirror under the focuser, a once in a while adjustment.

How different is that combo from say...this https://www.teleskop-express.de/shop/product_info.php/info/p754_Baader-Justierlaser-fuer-Newton-Teleskope-fuer-genaue-Justage.html

1 hour ago, Stu said:

It's f4.5, but yes it's a beast.

It can be a little frustrating having to adjust the tension using the elastic bungies when switching between eyepieces of very different weights.

That was with or without Paracorr?

30mm is a proper 1kg godzilla, no wonder it flexed 14 inches at F5.

Interesting @Stu, your Alkaid is 14, so larger than the production offered now. Have not read about mirror slip in 12s. How low was your low...I guess many nice objects are tantalizingly low up there, especially in summer. I tend not to observe DSOs under 20 degrees even at my dark site.

Mirror weight seems to be the same no matter the option and the thickness is indeed to prevent astygmatism on a simple cell.

Paracorr plus T6 is about the same weight as Ethos 17. Ethos 21 is on another level, a true beast. @GuLinux wrote that he experimented with 1kg and it was fine.

Has anyone tried Sumerian's EQ platform. It looks unbelievably light at 2.5 kgs...it appears not to be a big issue unless one is sketching as Alkaids seem to track smoothly.

@Piero @garryblueboy thank you both.

Quartz should flex less while cooling so less astygmatism. But cooldown might be just as long, as @Piero noted. It appears that the older models had more problem with flex and slop, I have read better reviews recently, and that might be due to streamlining of production. Prior runs were often custom-made with many little tweaks.

@garryblueboy was that 14 inches f5? trusses look looong...and the focuser is FTF, I believe a bit heavier than Moonlight CR2 they use now. Did it struggle with Ethos WITH Paracorr or without...and which Ethos...17 and 21 are true beasts. Did it go out of collimation when changing altitude? I've not read similar experiences with recent 12 f/5s...although have no idea whether it was Paracorr or not. Paracorr plus T6 is, I believe, below 700grams...

@Piero any particular suggestions for collimation tools?

Yes, the thread title is a knock-off of @Piero's Tak topic.

I've read many good things about Sumerian scopes (especially the latest generations). There were some hiccups but they appear to have been sorted out and the production is reduced and streamlined. TS takes European orders and imposes uniform mirror choices. Unlike @FLO, TS is not fun to deal with, slow to answer and the answers are terse and sometimes cryptic. Michael (who makes the scopes) does not appear to answer the mails (at least not yet to me) so I am left with the collective wisdom of the forum to pry some more information.

I understand that the 12 inch case weighs somewhere around 14kgs and the rest are truss poles. I'd be grateful if anyone comes up with the exact figure. Total weight is 16.5 as per both websites.

F RATIO AND BALANCE - Most reviews suggest that 10 inches version are bottom light and that they are not suitable for heavier eyepieces, and I presume Paracorr. 12 inches should have a better balance due to heavier mirror. Going F4 would make it more stable, sticking to F5 would make it easier to collimate, be easier on the EPs and (who knows) dissuade me from buying a Paracorr...straight away. I do notice coma at F5...

QUARTZ or PYREX - TS streamlined mirror offers to GSO Pyrex and TS branded quartz mirrors. At F5, both are available, at F4, only Pyrex. Quartz glass adds about 400eur to the bill, but the mirror seems to be 39mm thick just like Pyrex, presumably to avoid astigmatism because of the design of the cell. Lighter mirror would also be problematic because of the balance. So Quartz or not? There are fans behind, hopefully helping the cooldown and dealing with the boundary layer. Pyrex is slower to cool, but how much does that matter when you have the fans? Does Quartz offer much benefit when they are of the same thickness? GSO is Pyrex, Quartz is TS branded, anyone had any experience comparing them? 

So here are the options:

F5 and Quartz - more expensive, easier on the EPs (although mine are all TV in 7-24mm range). Might still itch for Paracorr on top of it, adding to the bill. I know I will, sigh. Less stable than F4 balance-wise, although T6 plus Paracorr is almost like an Ethos.

F4 - more stable, more demanding on EPs, Paracorr a must (there goes the balance advantage, although still less strain than F5 with Paracorr). Pyrex only.

F5 in Pyrex, easier on EPs than F4, easier collimation, slower cooldown, again Paracorr dilemma.

EQ Platform or not? Sumerian platforms are listed at 2 kgs weight...I find that hard to believe.

What are your thought and suggestions? 

I bounced from 127 to SCT8, than added two smaller refractors.

Honestly, it makes no sense to make jump in such small increments, as the others have suggested, go at least to 150mm. You may keep 100 Mak as a portable grab and go for airline vacations and the like.

SCTs are less taxing on the mounts than comparably sized Maks.

Holidays in Italy, mostly cities, but a short country stopover in Piedmont and I got to use it, some great views. Back home it's raining non stop, just in time for the new Moon 

15 hours ago, Sunshine said:

You guys are gonna get me in some hell with my wife, after spending a tidy sum on my Starmaster dob and a Star Adventurer months later, you guys are tempting me by waving a Quark under my nose with reports like this lol. This hobby is insatiable....please help me!.

Well I can help by telling you that, when it comes to astro views, my wife was so far impressed by three things only -  Moon, Saturn and proms in Quark. So chances are yours will like an occasional peek, too. Truth be told my wife never ever asks how much my toys cost...and I never ask how much her purses and shoes cost. Mutually assured financial destruction of sorts. 

Two of the  obligatory shots with a handheld phone. As always, they do not do justice.

I pulled a trigger on a Quark after reading a ton of positive and negative reviews. I already own two telescopes and could not sneak another past my family members unnoticed, and the idea of travelling light with essentially two scopes was appealing.  A pleasant surprise was that I did not have to buy a UV/IR cut filter, Neodymium took care of that.

Quark proved quite addictive, even though the Sun is fairly quiet now. I had several days with fair mornings and used them to the max (seeing in the city is pants in the afternoon), clocked easily 10+ hours over the course of four days already.

The first light coincided with testing of AzGTI. On UNI 18 it carries Tak 100 DF without problems, though fine focusing induces vibrations which die relatively quickly. Tracking is essential with Quark in Tak because the magnifications are large and FOV small.

Eyepieces used 40mm Celestron plossl, 32mm Baader plossl and 25mm Vixen NPL. Neodymium as ERF filter.

Did not take long to warm up, but I was probably somewhat overwhelmed by the novelty of both Quark and AZGti. Used Berlebach tripod for better stability. 

Quark brings focal ratios to f/24 for Borg and f/31 for Tak, and when viewing I thought that keeping it to 1mm exit pupil was the best for viewing, so NPL in Borg and Baader in Tak. That might change if i stop down Borg to up the f/level as I plan to. I have tried 40mm Plossl but I gain nothing, although it brings Tak magnification down to 77x. Perhaps a NPL 40 would be more comfortable, I doubt it. I will try stepping down Borg to 62 to see whether a longer focal ratio may improve contrast, but honestly I have not played with the Quark/Borg combo that much yet.

I was fiddling with the tuning, a lot. Not sure whether it is also f/dependent so one has to have two settings for two scopes. Daystar says that tuning is to offset focuser slop, but I am not entirely convinced. Tak and FTF focusers are not that shabby. Initial impressions were that the zero point is not bad, but-3 probably better. After four days of use I changed my mind and now -4 or perhaps -5 feel better in Tak, have not used Borg after the initial testing. Perhaps someone has some clever pointers how to estimate the best setting because between changing seeing and thermals it is fairly hard to be sure what is 'right'. I do not have camera so cannot resort to that (and heavy camera may indeed induce a slop not present when doing visual).

During one session I have not unscrewed the 2inch barrel so the 1.25 nose was not flush in my BBHS 1.25 clamp. That small tilt induced picture error and since then the 2 inch nose is removed.

I can see some contrast non-uniformity, but so far nothing dramatic.

I have mostly viewed in Tak and the close-ups of the proms (no other activity) are amazing. Eruptive prominences, QRFs, you name it, even those ring-like. Spiculae...and all of it changing relatively quickly. Eruptive prominence basically disappeared while my wife and I were viewing it. Wife was actually so impressed that she came to the idea to bring the scope to some charity event and raise money for the charity cause by offering view at the prominences. It was a complete hit, people were amazed (literally no one has ever peeked through a scope before, let alone H-alpha) and we raised a tidy sum. 

Other bits...solar observing hood (R-Sky, I think they are still on sale) proved to be invaluable and Baader plossl side-eyeguard is perfect for solar. I also like NPL quite a bit, nifty and light.

All in all this has proved to be a very very interesting inquisition. I am travelling light this summer (Borg only) and am hoping that Quark will diversify my viewing time and make me (at least a bit) more sociable in the evenings. Bring on some active regions!