Thinking of buying Sky-Watcher DOB-8" Retractable

[astrochumak]

Hello, can somebody please give some hints as to whether it's worth it or not?

I live in a Bortle class 5-6 zone with little to no chances of getting to a darker location any sooner. I've been owning already a Celestron Travel Scope 70, although was completely unsatisfied with its optical quality, so I sold one, and now I'm selling my Sky-Watcher MAK102 in order to get the DOB 8".  I have no car and I live in a 16floor tall house on the 3rd floor. So I have to carry the scope to the nearest park, which is about 15 mins by foot. That's why I'm thinking of buying the retractable tube, put it in some kind of a big bag on my beck (I've read that somebody had already done it), and carry the mount by hand. I'm 17 years old so it'll probably be no problem in terms of lifting.

So returning to my original question.. Is Sky-Watcher DOB-8" Retractable a good upgrade from MAK102, if I'm hoping to observe mostly brighter DSO (open clusters, bright nebulae) and planets occasionally, but in a light polluted area? Thank you!

[Ricochet]

I think an 8" dob might be too big for your travel requirements. If at all possible it would be best to wait until such a time that you can see one in the flesh before buying. Also, if you do decide to go ahead, the solid tube versions are lighter and probably more suitable for being carried on your back than the flex tube versions. 

Perhaps the smaller heritage 150p and a suitable mount with photographic tripod would be a more suitable and manageable option. 

[IB20]

I think if you bought the 8” dob you would carry it your observing area once or twice before you started actively looking for excuses to not take it out. It’s a hefty item to carry for 15 mins and I would look at something lighter. The heritage 150p gets good reviews and believe can be mounted onto a tripod easy enough. 

[AlexK]

8" is a good choice (even though with a collapsible I'd go all the way to the venerable 12") and definitely a significant upgrade to the 4" MAC (the rule of thumb is: double your aperture when you want to see more). That 150p heritage is indeed very popular but in fact quite junky (if you search for it on the forums you will find kilometers long threads discussing how to fix its numerous flaws) , especially with its particle-board semi-fork. I would hesitate to call it a Dob even to avoid insulting the marvelous Dobsonian mount  Besides, the Heritage is a tabletop. So you will have to haul a tripod as well, which is harder to conceal.

That retractable SW looks like a good compromise for the urban "concealed carry" task as well, even though a couple of kilos heavier than a solid OTA. In my 18 I've been a very slim built but have been carrying 70kg flour bags with no single sneeze by several dozens a day ("easy" money on railroad station loading/unloading work). A 8" SW should be a piece of cake for you. I know a guy hauling his 16" collapsible in the backpack to the 2km high mountain top through the snow almost every New Moon! I'm personally taking my 12" full OTA z12 Dob to the car trips and I do carry them from the car to the observing location for 50-100 meters into the open field easily in my bare hands. OTA in the right, base in the left, backpack with eyepieces on the back. You just need to attach proper handles to make it possible, as a 10-15 kg in each hand must be laughable for a man

On a side note. I'm living in the 15+ story high-rise apt complex in a heavily light polluted place too (on 10th floor though) and found its roof a way better observing choice than any local park around as all the lights around, haze and city smog being way below the 360 degrees round fully open horizon up there (well, I have a hill-top eucalyptus on the North-East blocking almost 20 deg, tbh). When the Ocean is calm the views are on par with the B3-4. The roof access door is locked (which is a security benefit for a solo observer too). But I have a key. Just try to approach your building management or security politely to allow you there occasionally with all necessary precautions and rules obeyed. It might turn out the person in charge might be interested in astronomy too! Also, in some buildings you can find public balconies on each or certain floors or in certain buildings you have lawful access to. Just research your artificial hills!

Edited November 23, 2020 by AlexK
(spelling)

[IB20]

If you can access your roof get the 8” (or 10”)!

[scarp15]

It could be worth it, if you can devise a good backpack, type of rucksack system for a collapsible 8". Also as you mention, if you have read up on someone who has actually done this. Certainly if you have a fairly quiet, fairly reassuring place to observe from not too far, an 8" dob will satisfyingly resolve open clusters, brighter DSO's from an urban park. I used to have an allotment and over this period established an 'observatory', paved area around the shed. From home I had carried various refractors or binoculars, tripods, a ten minute walk to the shed. By parking nearby, I have carried an 8" dob and previous to that, 8" SCT that required two, about six minute each way journeys. Your circumstance and age, if you did not follow your inclination for an 8" dob then you might regret less aperture. So long as you pace the journey, as it is a commitment requiring of course effort, but as mentioned if you do obtain an efficient carry system and feel committed enough it will be worth it. 

Oh welcome to the forum by the way.

[AlexK]

Ahh! The first post! Welcome!

Surely depending on the city park air conditions, but in my opinion, the skill of achieving and maintaining the eyes darkness adaptation in the heavily light polluted environment long enough from pointing at to observing of the DSO is the key to success, Bortle 9 or 1. But that's surely a totally different and huge subject of its own...

[astrochumak]

Thank you, everybody! I will try to speak to my house management. I really appreciate your help, you are so kind! Once again, huge thank you!!

[astrochumak]

So for anyone considering buying this scope or just wondering about the means of transporting it..


Here's how I did it.

I bought a giant military backpack, which is something around 320x350x950mm, for around 19 dollars, and it works great! The Dob mount is a little too heavy for long range carrying with the handle on it, though carrying it with two hands is no problem.  

As you can see, the backpack itself does not have tightening belts on the sides, which would be kind of helpful while you are going through the doors and other tight spaces, because the OTA inside kept leaning from side to side, which made the risk of knocking it with something much higher. But after all, it was a pleasant experience. If you don't have any beck issues or other weight lifting limitations, I would definitely suggest this method of transporting the dob

P.S. there was no access to the roof of my house, so i had to find another place for observations, hence backpack for transportation

Edited December 23, 2020 by astrochumak

[scarp15]

Excellent and well done 👍 A very good solution that you can adapt and modify as I'm sure by your account, that you will. I just wonder that for the base if an adapted shopping bag trolley to harness / strap it to might be a consideration. 

An intrepid approach can often work out. Yesterday evening I hiked a considerable way, not with a dob but a fairly weighty refractor, wood tripod, three eyepieces, mount, stool etc. across the Town Moor and up onto a small grassy hill, pretty rough going when off the footpaths and later in the dark. Beside the fact it became too cloudy for the Conjunction, It worked out just fine and is encouraging to do this again, if there is a need.

Anyhow look forward to further modifications and reports. 

Edited December 23, 2020 by scarp15

[Paz]

An 8" dob would be a good upgrade and a good scope for what you want to observe.

It's a case of transportation as already said. If you have any household bits and pieces that can be cobbled together to simulate the right weight and bulk you could try transporting that the same distance and see how it feels.

[Peter Drew]

Put some wheels on the base and drag the complete thing to your observing site?.        🙂

[astrochumak]

Thank you for your replies, I will certainly think of attaching wheels with some locking mechanism onto the base
Will update here if something will change!🙂

P.S.

1 hour ago, scarp15 said:

too cloudy for the Conjunction

Pictured on the photo above is me walking to an observing site for the Conjunction! It was cloudy in Kharkiv, as I remember, all the time since 10th of December, so clear afternoon on the 22nd was a blessing (the clouds appeared right after Conjunction)
I wasn't planning on imaging anything, but my girlfriend took the video anyways, so this day was the first time I ever tried to stack the photos and squeeze some details out of it all. But anyway, this is what we got with DOB 8" Retractable, Xiaomi phone and a flimsy 2 minute video:

And here's a single shot of the Conjunction right before two planets' disappearance behind the 16 flat house:

Edited December 23, 2020 by astrochumak

[scarp15]

A worth while incentive to take the 8" Flextube along to and nice capture and memento of that occasion. Became successful on my second attempt on Sunday, on that occasion taking binoculars and a monopod. A pair of binoculars and depending on the aperture, supported such as on a monopod would become complementary to the Dobsonian.

[AlexK]

Good job!

I'm sure you'll find the way to alternate/outfit that dry bag to secure the OTA.
For the base - it takes some practice to carry it conveniently by the handle. But I would make a bag for it as well, even if just to protect it from elements while carrying outside. Consider a cloth/PVC-fiber bag with two side handles, so your friend could help you carry it conveniently.

On a side note, I'd recommend to remove that eyepieces holder on the front of the base. It's just a snag-point. Keep eyepieces in your pockets, that will keep them warm and prevent fogging in the cold.

Regarding the roof access, you might also try other buildings around where you friends/relatives might live. I bet it's not a big problem in Kharkiv, there should be plenty of concrete-slab 10-story buildings built in 80es-90es (flat roof) around, just make new friends

[M40]

Very well done indeed 👍 Looks like a folding trolley is on the shopping list to help with moving the stuff.

[astrochumak]

21 hours ago, AlexK said:

Regarding the roof access, you might also try other buildings around where you friends/relatives might live. I bet it's not a big problem in Kharkiv, there should be plenty of concrete-slab 10-story buildings built in 80es-90es (flat roof) around, just make new friends

Thanks for your help! Man, I love SGL, there's so many good people out there, it's so nice