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Premium 6in f8 ota in USA?

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#1 dmgriff

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Posted 06 April 2016 - 11:57 AM

Thinking of getting a good premium grade 150mm f=1200mm f8 newtonian ota, but, where and by who in US?

 

I am not considering a atm project. So, who could supply one in the US?

 

I have a Astrozap gem with short steel tripod (lxd75 clone) to mount it on. This supports a 6in f8 dob ota with rings and dovetail well.

 

Orion Optics UK Great Britain, (not affiliated with Orion/telescope.com in US), has a VX6L ota with 1/10PV option for about 500usd (shipping not included).

http://www.orionopti...onianrefle.html

 

Thanks for information.

 

Good viewing,

 

Dave


Edited by dmgriff, 06 April 2016 - 12:03 PM.


#2 MikeMiller

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Posted 06 April 2016 - 12:23 PM

I don't think such a scope exists in the US, nor are there any dealers for the Teleskop-Service or Orion-UK premium/imaging newts. I've looked at some options for small-mid sized carbon fiber newts and came up empty.

All if the high end US scope makers focus on bigger apertures. Probably because the focuser, fans, etc are fixed cost making a small premium scope very expensive in. Look at the ASA Newts and Tak Epsilon for examples.

#3 Galicapernistein

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Posted 06 April 2016 - 12:45 PM

Discovery quit making their 6" dob years ago, and that's the only company I can think of that made high quality 6" mirrors. I have a 6" Orion Deep Space Explorer, that was made for Orion by Discovery before Orion started to import their telescopes from China. It's an excellent scope optically, but the sonotube is relatively heavy for a 6" scope, and even if you could find one used, it probably would require a fairly sturdy mount.



#4 macdonjh

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Posted 06 April 2016 - 01:04 PM

Comparing prices of Newtonian scopes with a Takahashi Epsilon isn't apples-to-apples.  The Epsilons have hyperboloidal mirrors and super-fast f/2.8 focal ratio.  Not comparable to a paraboloidal f/8 primary.

 

Robert Royce advertises 6" f/5 and 6" f/6 mirrors on his website for $100.  He might be willing to make a 6" f/8 mirror for you.  He was quite responsive to the questions I asked a few years ago.  If Mr. Royce makes a mirror for you it could then be installed in an off-the-shelf 6" f/8 OTA.

 

Another option is to buy the same stock 6" f/8 OTA and send the mirror off to be refigured and recoated.  Cary at OWL does this and I'm sure there are others.

 

I had a 6" Dobsonian from Orion (US).  The mirror was fine, but the mechanicals needed work.  I modified the azimuth axis and fixed the focuser.  I also added flocking to the focuser draw tube (the OTA was partially flocked when I bought it used).  If I'd wanted to "go all the way" I'd have changed the focuser for something from Moonlite.  When I was done it performed mechanically as well as any Obsession I'd used.  Of course it's a bigger deal to get a 15" scope mechanically right than a 6" scope.



#5 GShaffer

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Posted 06 April 2016 - 02:28 PM

You might consider buying a premium 6" mirror and components and sending them to Parallax. He makes some nice builds....

One option would be here....mirror #3 is .988 strehl 6" f/7.89
 


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#6 gene 4181

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Posted 06 April 2016 - 02:48 PM

 Parallax , but if you want to look,  www.ohiotelescopeandmicroscope.com , he's got a couple of  criterion or Edmunds old school  stuff , 2 -6's and an 8in f7 on the mounts , Just talked with the guy , the original eyepieces come with the scopes too.   And they are Criterion's


Edited by gene 4181, 06 April 2016 - 03:19 PM.


#7 CP Kuiper

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Posted 06 April 2016 - 02:55 PM

Non-functioning link. 

 

"This site can’t be reached

www.ohiotelescopesandmicroscopes.com’s server DNS address could not be found."



#8 gene 4181

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Posted 06 April 2016 - 03:17 PM

   www.ohiotelescopeandmicroscope.com , my bad,  ,  :lol: , fixed


Edited by gene 4181, 06 April 2016 - 03:43 PM.


#9 dmgriff

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Posted 07 April 2016 - 09:34 AM

Those old Criterions look great and reasonable price. May be a pain (for me) if something needs repair electrically, and looking for something new.

 

I thought a 6in f8 ota might wind up a part/piece/tube and someone assemble it plus shipping costs. This causes the price to escalate quickly. Note a 60mm refractor pieced on ebay exceeds by about 3 or 4 times the amount for a ebay factory ota.

 

Noting the price lists at Orion Optics UK, the price of a mirror/secondary and cell purchased separately exceed the price of a complete VX6L ota. 

 

I have requested price and shipping information to USA for the VX6L 1/10PV option.

 

Good viewing,

 

Dave

 

 



#10 otocycle

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Posted 08 April 2016 - 04:09 AM

In 2014, I was shopping around for a new 6" f/8 telescope.    I wanted the OTA to play with two mirrors I made back in the 1970s...just swap them out in the mirror cell.

 

The only readily available product was Orion's XT6 Dob for about $300....not made in the USA but certainly good enough for my intended purpose.  

 

For extra old school fun, I bought a Criterion RV-6 mirror and diagonal set at auction for $65 just to see how good the optics were "back in the day".



#11 catboat

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Posted 08 April 2016 - 07:48 AM

 

 

Noting the price lists at Orion Optics UK, the price of a mirror/secondary and cell purchased separately exceed the price of a complete VX6L ota. 

 

I have requested price and shipping information to USA for the VX6L 1/10PV option.

 

Good viewing,

 

Dave

 

I noticed this too.  The entire Orion UK OTA (upgraded to 1/10 wave primary) costs a bit less than the cost of their 1/10 wave primary and the mirror cell (impressive!) when purchased separately.  It doesn’t make sense to me.  It doesn’t seem possible.  Even if the primary in the complete OTA was the lowest grade they offer, the OTA price would still be hard to believe.  If the optical quality is seriously good, these OTA prices can’t be beat.   For comparison, an RF Royce 6” primary alone will cost close to $500.  Other premium makers would be in that ballpark as well.

 

Anyway, before I checked the Orion UK site, I had the following in mind even though you said that you didn’t want want an ATM project.  It’s probably a no-go if the Orion UK prices are accurate and if they can deliver the optical quality, but here goes anyway:

 

If you buy the components, assembly of an OTA is simplicity itself -- a screw driver and a drill.  "Newt for the web” will give you the correct spacing for mounting the components once you have the dimensions of the components you’ll actually be using.   If you prefer not to assemble it yourself, I’m sure you could find someone local who would do it for little cost (a cabinet maker, mechanic, anyone handy).

 

There are options for each component but by way of an example:

 

primary: RF Royce
primary cell:  (several suppliers)
secondary mirror: Antares Optics or Astrosystems
spider, secondary holder: Astrosystems (made to fit your tube)
focuser: MoonLite
tube:  7.5” ID phenolic “rocketry” tube form Public Missiles  (light weight, rigid, and easily worked with hand tools).

 

Blacken or flock the inside of the tube, and you’d have a premium 6”.  


Edited by catboat, 08 April 2016 - 07:50 AM.

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#12 SeattleScott

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Posted 09 April 2016 - 12:45 AM

Parks used to make premium newts in US. I checked into them and OO. Parks was more expensive but pulled even when factoring in high shipping costs for OO. You will probably pay $40 for customs duties in addition to foreign exchange fee and shipping. The international fees kind of suck but the scopes are well priced, so it makes shipping costs more tolerable. I have to collimate my 10" F4.8 a couple times a year. I have to collimate my 6" Orion XT whenever I sneeze on it. Good focuser, light, fast cool down, top of the line coatings, excellent optical quality if you pay the extra, basically really nice scopes. I am about to order a sheet of flocking paper as a finishing touch to help with stray light, as the tube does not extend quite as far as most. Smaller cars in Britain?

 

so how much does a 10" reflector on an eq mount weigh, including mount, counterweights and standard accessories? For me, 69 lbs. Ordering from the Orion USA catalog, 117 lbs. Granted you are looking at a 6" so weight may not be as big a deal, but it helps. 

 

Scott



#13 dmgriff

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Posted 09 April 2016 - 07:28 AM

Thanks SeattleScott for the OO info.

 

I should receive the price and shipping info in a couple of days, Monday or thereafter.

 

Catboat, thanks for a list of possible suppliers of quality equipment to build a ota. 

 

I have hip problems, so heavy stuff is kinda out for me. The VX6L weighs 5kg (11 lbs?) stripped. A collapsible wire mesh cart from the hardware store or a 4 wheel yard cart assists me in cartage to a ApogeeInc gem and Astrozap gem I keep setup and covered in the back yard. If I feel the need to, a VMC110L f9.4 modified mak-cass on a Nexstar GT mount as a "finder scope" is setup.

 

I have bigger dobs, but, I think the VX6L ota would be my large aperture scope, due to the hip issue. A quality optics 6in f8 newt ota on a gem could easily keep me busy with lunar, planetary, some dso for a lifetime. The 2in focuser should support my Burgess Model 24 bv's.

 

Good viewing,

 

Dave


Edited by dmgriff, 09 April 2016 - 11:59 AM.

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#14 Patrick

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Posted 11 April 2016 - 10:34 PM

"A quality optics 6in f8 newt ota on a gem could easily keep me busy with lunar, planetary, some dso for a lifetime."

 

I love the views through a 6" f/8.  My very first scope was an Orion 6" f/8 that served me well for several years, including using it on a CG-5 mount.

 

The one thing I will say about using the Newt on a GEM is that I found it to be pretty uncomfortable.  There are some parts of the sky that are very difficult to view in without rotating the scope in the tube rings.  Then you have a whole range of issues to deal with in learning how to rotate the scope.  It ends up not being very fun.

 

Personally, a 6" f/8 in a Dob format makes a whole lot of sense in terms of ease of use.  Moving one about it relatively easy, and the viewing position is constant except for elevation.

 

One other thing, even my Orion 6" f/8 had really good optics and put up some fantastic images. 

 

Patrick



#15 SeattleScott

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Posted 11 April 2016 - 11:14 PM

F8 tends to be pretty forgiving. Now the issue is almost more about the mechanics. My Orion 6" Dob sucks at holding collimation, can't support eyepieces heavier than a TMB Planetary or Meade HD, and requires a lot of bending over being a Dob. It doesn't have a dual speed 2" focuser and the finder scope is, wait a second, I don't think I am allowed to say that here. And it has a heavy steel tube, whereas it sounds like portability is a key issue, and favors the lighter aluminum tube and thin mirror of the OO model. Maybe the blue tube version is better, and I guess you can get a stand to raise the height, but what about tracking? I totally get the tube rotation thing, which is why I ordered mine with an extra tube ring. I get the impression this guy has been in the hobby awile so I figured he probably knows about the tube rotation issue, but it is a valid point. For that matter OO sells a Dob mount, so he could get a Dob from them. To me it is really a quality thing. I know OO isn't the top of the line, Moonlight focuser, flocked tube, etc. But it is light years ahead of an Orion US classic Dob. OO is clearly a step above the mass produced Chinese stuff in my experience, and they are not exorbitantly priced like the top of the line stuff. A good option for someone who wants a quality product but can't pay thousands for a 6" reflector. 

 

Scott



#16 dmgriff

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Posted 12 April 2016 - 09:44 AM

I guesstimate the parts for a what I would call a quality 6in f8 ota at over $1000usd and a premium ota at over $1500+usd. Lets say $450-$600 for the mirror $200-$450+ for a focuser, add a secondary, mirror cell, spider, tube, raci finder, rings, dovetail plus whatever else and the cost escalates.

 

The VX6L 1/10PV price, tax, shipping should be less than the quality parts price.

 

My other option would be a new Skywatcher (31010), Orion or GSO dob, with the new alt bearings, and obtain a quality optic that will drop in. I would still have a dob ota (I cant leave a particle board mount outside), and, I prefer a gem mount with tracking for my use. OO UK does make a nice looking metal dob base with cradle/rings (looks like it could be left outside with proper covering), but, due to tax and shipping on that, it may be cheaper to have a similar base fabricated in the US.

 

I do have a Hardin (GSO) 6in f8 dob, balanced with magnets, raci finder, ptfe, original optics (nice). I can use the ota on a gem, but, for a permanent mounting, the bearings get in the way, and it could use a upgrade imo. I plan to give the Hardin to a friend nearing retirement as his "first scope".

 

Just my reasoning, or lack thereof.

 

Good viewing,

 

Dave


Edited by dmgriff, 12 April 2016 - 09:52 AM.


#17 GShaffer

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Posted 12 April 2016 - 09:48 AM

"A quality optics 6in f8 newt ota on a gem could easily keep me busy with lunar, planetary, some dso for a lifetime."

 

I love the views through a 6" f/8.  My very first scope was an Orion 6" f/8 that served me well for several years, including using it on a CG-5 mount.

 

The one thing I will say about using the Newt on a GEM is that I found it to be pretty uncomfortable.  There are some parts of the sky that are very difficult to view in without rotating the scope in the tube rings.  Then you have a whole range of issues to deal with in learning how to rotate the scope.  It ends up not being very fun.

 

Personally, a 6" f/8 in a Dob format makes a whole lot of sense in terms of ease of use.  Moving one about it relatively easy, and the viewing position is constant except for elevation.

 

One other thing, even my Orion 6" f/8 had really good optics and put up some fantastic images. 

 

Patrick

 

The prime reason for the expense of rotating rings...... I have a set of parallax rotating rings on my 10" f/5 newt and they are worth every penny.



#18 Pinbout

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Posted 12 April 2016 - 09:54 AM

I love my 6in f8...still have to coat the mirror but wow...

 

and all I have to do is loosen the rings and rotate the tube, no problem, and saves on weight which is easier on the mount.

 

the best mount would be a dm4  but even my desertsky mount has no problem at high mags

 

post-106859-0-72405600-1458758415.jpg


Edited by Pinbout, 12 April 2016 - 09:55 AM.

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#19 Traveler

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Posted 12 April 2016 - 11:46 AM

Not so long ago i watched the Moon and Jupiter in a Skywatcher 150mm F8  Newton (OTA newprice under 300 euro). I was very impressed how good the views were with that scope!


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#20 macdonjh

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Posted 12 April 2016 - 12:23 PM

F8 tends to be pretty forgiving. Now the issue is almost more about the mechanics. My Orion 6" Dob sucks at holding collimation, can't support eyepieces heavier than a TMB Planetary or Meade HD, and requires a lot of bending over being a Dob. It doesn't have a dual speed 2" focuser and the finder scope is, wait a second, I don't think I am allowed to say that here. And it has a heavy steel tube, whereas it sounds like portability is a key issue, and favors the lighter aluminum tube and thin mirror of the OO model. Maybe the blue tube version is better, and I guess you can get a stand to raise the height, but what about tracking? I totally get the tube rotation thing, which is why I ordered mine with an extra tube ring. I get the impression this guy has been in the hobby awile so I figured he probably knows about the tube rotation issue, but it is a valid point. For that matter OO sells a Dob mount, so he could get a Dob from them. To me it is really a quality thing. I know OO isn't the top of the line, Moonlight focuser, flocked tube, etc. But it is light years ahead of an Orion US classic Dob. OO is clearly a step above the mass produced Chinese stuff in my experience, and they are not exorbitantly priced like the top of the line stuff. A good option for someone who wants a quality product but can't pay thousands for a 6" reflector. 

 

Scott

 

My son and I used an Orion XT6 for a couple of years.  I was surprised how good the optics were for a $300 telescope.  I agree with you, though, that the mechanics needed work.  I modified the focuser by installing shims between the body and draw tube, which fixed most of the slop and solved collimation issues generated by the focuser.  I installed a Lazy Susan bearing for azimuth movements to deal with the sticktion of the stock pads.  Of course, the Lazy Susan had too little friction, so I also had to install a "drag pad" so I could adjust the amount of friction in azimuth.  A bit of flocking and lots of fiddling made the scope perform very well. 

 

I hope my son will one day regret telling me he didn't want to observe anymore and that I should sell the scope. :)  It's got a home in our club's loaner program now.



#21 Astrojensen

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Posted 12 April 2016 - 03:15 PM

Not so long ago i watched the Moon and Jupiter in a Skywatcher 150mm F8  Newton (OTA newprice under 300 euro). I was very impressed how good the views were with that scope!

I have one of those, which I use on an EQ-6 with shortened tripod. For such a cheap scope, it has AMAZING optics!!! A tad of astigmatism (slight) and a bit of overcorrection, but VERY smooth optics that give superb contrast and very dark sky backgrounds and pitch black crater shadows on the Moon. It is a VERY competent lunar-planetary scope, which easily outresolves a $4000 100mm apochromat I have on loan, and shows more details on Jupiter. I *HIGHLY* recommend them to everyone wanting to see what all the "6"f/8 newtonian fuzz" is all about. 

 

gallery_55742_4249_83221.jpg

 

It holds collimation extremely well. The finderscope is pretty mediocre, but does the job OK on bright objects. The focuser is smooth, but is only a 1.25". It does have Vixen M43 threads as well, so you can get a Baader M43/T2 adapter and then use a T2/M48 adapter to thread 2" eyepieces directly onto the focuser tube. It will reach focus with a 30mm ES82 with only slight vignetting and the views are super crisp across the field. 

 

I was out with this scope last night, observing the waxing crescent Moon with a binoviewer at 160x and was, as always, flabbergasted by how crisp and sharp it is in good seeing. The rilles in Atlas could be seen really well and both Atlas and Hercules were surrounded by seemingly thousands of secondary ejecta impact craters. A truly superb view.

 

One thing, that I've found to be tremendously important, is to use a tube extension in front of the tube. I use a C6/C8 dewcap. This keeps my breath and body heat out of the light path and this improves image stability noticeably.

 

Bottom line, I HIGHLY recommend this scope. For under $300, and outperforming world-class 4" apochromats, it's close to be the deal of the century. 

 

 

Clear skies!

Thomas, Denmark 


Edited by Astrojensen, 12 April 2016 - 03:19 PM.

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#22 aatt

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Posted 15 April 2016 - 11:36 AM

Find an old Orion DSE. The mirror in mine is phenomenally good. Mount has balancing issue with heavy eyepieces, but that is an easy fix.They occasionally pop up on Craigs list at a bargain price.


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#23 Galicapernistein

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Posted 15 April 2016 - 01:25 PM

Find an old Orion DSE. The mirror in mine is phenomenally good. Mount has balancing issue with heavy eyepieces, but that is an easy fix.They occasionally pop up on Craigs list at a bargain price.

I had mine out last night and I agree 100%. The quality of the mirror really shows when you're using 200x and the image is still sharp. Some night I'm going to compare it to my Sky-Watcher 100ED to see how it stacks up against a quality refractor, but I think it will hold its own.



#24 Bonco

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Posted 15 April 2016 - 03:13 PM

A used RV6 OTA properly collimated with fresh coating will reveal just about all that a 6 inch telescope can deliver. Several mounting options would be available. Even the original mount is very functional and rotating the tube is easy by loosening the rings.

The focuser is the one thing I'd replace.  Very low cost/high performance.

Bill 



#25 Astrojensen

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Posted 16 April 2016 - 12:45 AM

 

Find an old Orion DSE. The mirror in mine is phenomenally good. Mount has balancing issue with heavy eyepieces, but that is an easy fix.They occasionally pop up on Craigs list at a bargain price.

I had mine out last night and I agree 100%. The quality of the mirror really shows when you're using 200x and the image is still sharp. Some night I'm going to compare it to my Sky-Watcher 100ED to see how it stacks up against a quality refractor, but I think it will hold its own.

 

It should EASILY outresolve the ED100 if it is any good. In fact, if it is "phenomenally good", it will be so far ahead of the ED100, that there's basically not much reason to use the latter. 

 

My own Sky-Watcher 150mm f/8 has a good mirror, but far from a perfect one. It's smooth (very little scatter), but has a tad of astigmatism and some overcorrection. It easily outperforms a 4" apochromat on the Moon and Jupiter. 

 

 

Clear skies!
Thomas, Denmark


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