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Pretty decent deal on a 20"

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#26 Jon Isaacs

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Posted 10 November 2018 - 11:33 AM

I prefer to use a ladder I am very unlikely to fall off of over a tall step ladder with my 20" f/5.....Its a $150 4 step (total) with wide steps little giant jumbo step with non-skid rubber on the steps, has a handle/lean bar/eyepiece holder hip high above the top step and the top is extra wide.....I guess one could call it a "serious" ladder in a sense but certainly not height/size wise unlike the tall step ladder you showed......

 

A photo would be helpful.  Railings to lean against are really nice and transform the viewing experience.  Just missing the bottom step step on the way down and taking a tumble is enough of a fall to be seriously hurt.  Having a railing to hold onto, lean against, shallow step angles, wide steps.  

 

A scope like this requires a real ladder.  A scope with a 76inch focal length might get by with a short stool and one can get by without the stool for much of the sky.  For my 22 inch which has a slightly shorter focal length than a 20 inch F/5 and a very similar eyepiece height, I can view standing up to 40 degrees elevation.  Beyond that it requires a ladder. I am 6 ft.   So with a scope like this, much of the viewing is done with a ladder.  

 

The gain of a 20 inch over a 16 inch is slightly less than 0.5 magnitudes, significant but not so different.  A 16 F/4.5 inch is much easier to setup, transport and does not require a ladder.  A shorter observer may require a single step stool.  An 18 inch F/4 is bigger, gives up about 0.22 magnitudes to a 20 inch but again does not require a ladder, etc.

 

What I see is that with the arrival of the Paracorr 2 and sub F/4 scopes, these older scopes have become relatively inexpensive.  As I said, I don't see $5000 as a steal, it's a reasonable price and a good scope.  If you haven't spent much time with a 20 inch F/5, it's good to consider just how big it is and how much hassle a ladder is. 

 

Jon 


 

#27 stargazer193857

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Posted 11 November 2018 - 12:36 AM

I remember looking at the obsession website 3 years ago. The slowest scope over 12" they had was f4.5. Now the 20" and 25" are f4. I know a public observatory with a 25" f5. Now I know it must be old. I walked up the stairs. Lots of them. People will still buy them used, but at a discount.

As for the Obsession 15" f4.2 UC, it is $5500. That should persuade some people to save money on yesterday's technology.
 

#28 stargazer193857

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Posted 11 November 2018 - 12:47 AM

I looked through an 18" f4.5. I needed a stool, and sometimes a second step.

If strong Jon says a 16" f4.5 is much easier to set up than a 20" f5, I would pay attention and think twice before getting the 20" f5.

I looked at M51 in a 20" f4.5, and it looked like a small Hubble pick, blue with purple knots. The 18" I looked though showed it much more ghostly. Both at Bortle great sites, different nights. 12" can show a bright white spiral. Depends a lot on magnification.

Edited by stargazer193857, 11 November 2018 - 12:48 AM.

 

#29 stargazer193857

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Posted 11 November 2018 - 12:51 AM

As for hassle, one must look at the hassle of going to a dark sky site, and ask once there which aperture they would rather look through.

Standing is not an option for my knees. I like to sit comfortably. So 12" f4.5 is about right.
 

#30 Jon Isaacs

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Posted 11 November 2018 - 04:15 AM

As for hassle, one must look at the hassle of going to a dark sky site, and ask once there which aperture they would rather look through.

Standing is not an option for my knees. I like to sit comfortably. So 12" f4.5 is about right.

One can sit with a Catsperch Pro chair with a 16 inch F/4.5..

 

5838018-Catsperch with Dobstuff Dob.jpg
 
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#31 Fatcat

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Posted 11 November 2018 - 05:09 AM

I would jump also but it is not fitting in the Vette.

Corvettes suck! I had 60 of them and only 5 were any good especially that one from 1980 i never should of sold.


 

#32 stargazer193857

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Posted 11 November 2018 - 08:55 AM


One can sit with a Catsperch Pro chair with a 16 inch F/4.5..



Jon


That might be comfortable if the step were a bit deeper. I guess on a cold night I would not mind keeping my feet and legs together.
 

#33 tomykay12

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Posted 11 November 2018 - 01:19 PM

Jon, we really need to paint your ladder.


 

#34 CHASLX200

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Posted 11 November 2018 - 03:32 PM

Value of these beasts is really not that high, to be frank.  There is a reason they are so heavily discounted.  Very small market of buyers who want such large scopes anymore.  Those with $$ for big scopes will likely spring for newer, faster, more compact and refined designs.  So you really have a limited market to sell too. 

I would be all over it if it would roll out my door 100% setup.  I don't think it would fit thru the door.


 

#35 CHASLX200

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Posted 11 November 2018 - 03:34 PM

Corvettes suck! I had 60 of them and only 5 were any good especially that one from 1980 i never should of sold.

Yes the new C7's do suck buck. Some of these new Vette are  on 3 replacment trans and T/C's under warranty and sitting at dealers on months on end.


 

#36 George N

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Posted 11 November 2018 - 03:53 PM

I remember looking at the obsession website 3 years ago. The slowest scope over 12" they had was f4.5. Now the 20" and 25" are f4. …...
As for the Obsession 15" f4.2 UC, it is $5500. That should persuade some people to save money on yesterday's technology.

 

A few months ago I set up next to a guy with an Obsession 18 Classic that he had just bought from the first owner. While the price was startlingly low, the primary was in obvious need of a re-coat (even had some "leopard spots" from a period of non-use and damp storage). Hopefully the primary is not in need of replacement. The telescope structure still performed like Obsession is famous for - smooth, no stiction, stiff and holds collimation, etc.

 

The owner claimed that he called Obsession to ask about used prices on the scope before he got it. He said he was told that only a small percentage of Obsession sales now includes the 'classic' design. I think he said 'classic' sales were now around 20%. The last time I heard, even DaveK uses a 22UC for travel, leaving his 25 in his roll-off roof observatory.

 

A good friend makes and sells premium Dobs. He told me that 80% of his customers are age 70 or older. That may help explain the frequent concern about ladders - but still, Dobs in the 18" and larger size have never been anything but a limited specialty telescope. As one friend who owns an Obsession 36 told me "Owning a scope like this is a lifestyle choice - like joining a monastery or getting married." He also said he wishes he had kept his Obsession 20 and not moved up to the 36 - but he has been saying that for 15 years and still has the 36.

 

Larger premium Dobs have always suffered a substantial loss in re-sale value and I have assumed that is related to the difficulty of finding a buyer in "no-shipping range" - and the understandable reluctance to buy such a costly beast sight-unseen. I purchased my made-in-2000 Obsession 20 F/5 around 2004 from the 2nd owner - and the scope came with many nice mod's added. I paid around 50% of the then new price- less mods - and the seller delivered it 200 miles to my house - with the understanding that I would not buy it unless it was in good shape. I still paid at the high end of what they were going for used at the time - but I got my scope in 2 days from a guy with a good reputation as a seller/buyer. Turned out that he was a lawyer who specialized in enviro-law - and his reason for selling the 20 was not his personal issue with using ladders - but rather his wife's concern about their two children on the ladder. He said that when the kids got to be teens he would be going back to a 20.

 

While I can understand the appeal of going ladder-less ( I'm now 71 myself ) - I think a used Obsession 20 in excellent shape - at 5 grand, or maybe less, would be a fine idea for a 40 to 60 year old in good health. People in that age bracket are often more constrained by finances then physical issues. At that age I hiked 18 miles at a time, ran 25+ miles per week, and walked a hilly 18 hole golf course 2 or 3 times a week. Ladders or Obsession 20's were not any sort of physical challenge. When I first got the scope I did not even have ramps. My wife and I just picked it up and put in the back of the Tahoe - and sometimes just carried it inside rather than rolling. Today I need to be very careful with putting that UTA on or off - especially if everything is covered with dew or frost.


Edited by George N, 11 November 2018 - 04:00 PM.

 

#37 George N

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Posted 11 November 2018 - 04:08 PM

I would be all over it if it would roll out my door 100% setup.  I don't think it would fit thru the door.

 

I had that problem for years. I had to do some twisting and lifting to get my Obsession 20 thru the door. Now I have 'bat wing' French doors - and could fit a 50+ inch thru there.

 

Bottom like - fitting thru the door *is* an issue with a big classic 20-inch - especially with a StellarCat on it making it wider.


 

#38 George N

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Posted 11 November 2018 - 04:31 PM

…….

I looked at M51 in a 20" f4.5, and it looked like a small Hubble pick,.....

 

Try looking at M-51 in a 36-inch from a site with an SQM reading of 21.85.....  ;)

 

Everyone has a personal preference in such things - but it is best to see a scope in action at a star party before plunging into a purchase.

 

In my case I had friends and frequent fellow observers - a husband/wife couple - who owned an Obsession 20 (and a C-8) for at least 5 years before I bought mine - so I knew quite well what it took to set up and use. I've also used an OGS 20" F/8 RC since 1993 - so I know what a scope this size shows.

 

Just a few months ago - sitting at Cherry Springs Dark Sky Park with friends discussing my interest in going ladder-less in the next year or three.... the owner (and maker including optics) of the 36" F/3.5 I was set up next to said "After over 20 years of using a 20-inch, you are never going to be satisfied with the views thru a smaller scope!" I think he's right. If I get to the point I can no longer observe thru a 20 or larger I'll be going from 50% imager to 100% imager. Unless there's a nice scope set up next to my imaging rig of course.....  ;)


 

#39 CHASLX200

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Posted 11 November 2018 - 04:31 PM

I had that problem for years. I had to do some twisting and lifting to get my Obsession 20 thru the door. Now I have 'bat wing' French doors - and could fit a 50+ inch thru there.

 

Bottom like - fitting thru the door *is* an issue with a big classic 20-inch - especially with a StellarCat on it making it wider.

I had a 18" Tectron that would fit thru the door.


 

#40 Redbetter

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Posted 11 November 2018 - 08:33 PM

A 20" classic Obsession rocker box will fit through standard doors without problem, if one simply replaces the eye bolts in the handles with something closer to flush and easier to use.  I don't recall the dimensional change exactly, I think it was something like 0.75" on each side.


 

#41 Jon Isaacs

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Posted 11 November 2018 - 08:48 PM

"After over 20 years of using a 20-inch, you are never going to be satisfied with the views thru a smaller scope!" I think he's right. If I get to the point I can no longer observe thru a 20 or larger I'll be going from 50% imager to 100% imager.

 

 

That has not been the case for me.  I'm happy with most any scope . It's a different experience but there's still plenty to see . Don Pensack points out that he'll never run out of new objects to see in his 12.5 inch . 

 

I'm happy with my 16 inch when it's too windy or I don't have the energy for the larger scope. 

 

Jon

 

Jon


 

#42 Spartinix

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Posted 12 November 2018 - 01:17 AM

When I got the chance last year to buy a 19.5" F5 mirror set, I was hesitant about the height and having to use a ladder. I was used to observe sitting comfortably behind a very nice 14" SCT, and the plan was to upgrade my homemade fork for it to an EQ8 mount, but I was tempted by more aperture and F5 vs F10 so I went for it.

 

In the beginning I wished I could have that aperture at F3 but with a better, more stable ladder last winter, I`ve been okay. Depending on the altitude I`m observing at, I place the ladder in different orientations and I can lean against it while observing. It`s actually very comfortable and I think I`m changing positions faster than I would with a Catsperch chair system.

 

Needless to say, going from 14" to 20" made a big difference. My telescope is not finished completely but I`ve had some very memorable views through it on a few dozen occasions.

 

As soon as I`d run into trouble as I get older, I`d love a 28" F3 or more realistically, some widefield 10-14" binoscope.


Edited by Spartinix, 12 November 2018 - 01:19 AM.

 

#43 Shneor

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Posted 12 November 2018 - 02:39 AM

I recently purchased a new-to-me Hubble 18" for the time when I presumably won't be able to carry around the heaviest part of my 22" (just over 60 pounds). The heaviest part of the Hubble is about 35 pounds. I've used it briefly a couple of times around my home (just pure and unadulterated light pollution). I use a 3-step Cosco ladder for the 22", and I have never found it to be a problem. I need to stand on the top step to install and remove the upper ring. The steps are almost a foot deep. I also being a pair of binos and an  "antigravity" chair if I get tired of standing or sitting. I have also set up an AWB and a 10" truss in front of my home when three planets were visible earlier this year, and actually managed to observe M57, M8 and the Veil (NPB filter) as well from a nearby back yard with the 10".

 

I'm almost in my mid-70s. The other day I read about high intersity interval training and have incorporated it in my morning exercise routine...

My point is, keep active as much as you can to exend the time you can use your larger scope, be prepared to downsize when absolutely necessary. Any reasonably well made telescope can show you a variety of objects.


 

#44 dgoldb

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Posted 12 November 2018 - 11:21 AM

That same scope is still $9k new without the long list of accessories and upgrades......and servocat costs and is worth the same regardless of what scope it is on......$5k is a steal considering whats included (to be Frank lol)

I think you are underestimating the loss in value of these scopes.  5k seems appropriate, not really like a steal.  I see "steals" like this all the time.  And just because a new scope costs 9k doesn't mean its properly valued; there is a reason obsession is now selling more of the new style than the classic (despite poor reviews on the UC).  I doubt the traditional scope is even for sale in 5 more years.  Oh and servocat is not worth the same regardless of the scope.  Perhaps if he was selling it separately it would be, but he isn't. The servocat is being sold as part of a package with the scope.  I see people all the time list all the retail prices of the additions they have, and then add it all up.  But human beings don't value items as the sum of their parts.  They (properly) value them as a whole.

 

Not bashing the scope - it will work great for some people.  But most people are not looking for such a scope, and that reduces its value substantially.  It is like selling a home with pink carpet, floral wall paper, gold hardware, and a closed-floor plan.  Fine in the 70s, but not now.  And the servocat is like saying "but the home has a nice furnace! that's worth a lot!"  People don't value things like that.  


 

#45 RobertMaples

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Posted 12 November 2018 - 12:59 PM

A photo would be helpful...

I believe this is the ladder GShaffer was talking about.  Here's another option, and there are many more similar designs available that would give you a safe, stable platform 2.5 - 3' off the ground, which would be plenty high enough for that scope for most people.


Edited by RobertMaples, 12 November 2018 - 12:59 PM.

 

#46 Redbetter

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Posted 12 November 2018 - 01:50 PM

I recently purchased a new-to-me Hubble 18" for the time when I presumably won't be able to carry around the heaviest part of my 22" (just over 60 pounds). The heaviest part of the Hubble is about 35 pounds. I've used it briefly a couple of times around my home (just pure and unadulterated light pollution). I use a 3-step Cosco ladder for the 22", and I have never found it to be a problem. I need to stand on the top step to install and remove the upper ring. The steps are almost a foot deep. I also being a pair of binos and an  "antigravity" chair if I get tired of standing or sitting. I have also set up an AWB and a 10" truss in front of my home when three planets were visible earlier this year, and actually managed to observe M57, M8 and the Veil (NPB filter) as well from a nearby back yard with the 10".

 

I'm almost in my mid-70s. The other day I read about high intersity interval training and have incorporated it in my morning exercise routine...

My point is, keep active as much as you can to exend the time you can use your larger scope, be prepared to downsize when absolutely necessary. Any reasonably well made telescope can show you a variety of objects.

That is the same ladder I have been using since 2003.  Finding a ladder that works well with the scope makes all the difference.   The tray makes a difference too since I keep my working set of eyepieces in an insulated box on the tray.  The collimator parts sit on the tray as well, for when I want to do a touch up for large changes in elevation angle or if I can see it is off. 

 

One of these days I would like to fabricate a holder for charts or Uranometria to extend off the right hand side of the ladder (away from the eyepiece)...something like a music stand with a way to secure an open atlas.  Hmm...I think I just figured out a good way to configure this and how I might attach brackets.   

 

For a much larger scope with around 120" focal length I wish I could get a scaled up version of this ladder, adding two more steps and a slightly greater width to compensate for the increased height.  I am thinking of it as more of a fixed location ladder with level/prepped ground, but it would work as a travel ladder with a monster scope because it would be trailered and the ground would need to be a somewhat more level/regular than what I use the 20" on.


 

#47 GShaffer

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Posted 12 November 2018 - 02:37 PM

I believe this is the ladder GShaffer was talking about.  Here's another option, and there are many more similar designs available that would give you a safe, stable platform 2.5 - 3' off the ground, which would be plenty high enough for that scope for most people.

 

That is exactly the one Robert.....and I modded the top rail as an EP holder......Never felt unsteady, steps are almost as wide front to back as my shoes. Its a great match for my 20" f/5


 

#48 Jon Isaacs

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Posted 12 November 2018 - 06:55 PM

That is exactly the one Robert.....and I modded the top rail as an EP holder......Never felt unsteady, steps are almost as wide front to back as my shoes. Its a great match for my 20" f/5

 

I have a similar ladder . I will only say having railings to lean against and to hold onto are very nice to have.  Two hands for the scope..  

 

YMMV

 

jon


 

#49 CHASLX200

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Posted 12 November 2018 - 07:05 PM

I think you are underestimating the loss in value of these scopes.  5k seems appropriate, not really like a steal.  I see "steals" like this all the time.  And just because a new scope costs 9k doesn't mean its properly valued; there is a reason obsession is now selling more of the new style than the classic (despite poor reviews on the UC).  I doubt the traditional scope is even for sale in 5 more years.  Oh and servocat is not worth the same regardless of the scope.  Perhaps if he was selling it separately it would be, but he isn't. The servocat is being sold as part of a package with the scope.  I see people all the time list all the retail prices of the additions they have, and then add it all up.  But human beings don't value items as the sum of their parts.  They (properly) value them as a whole.

 

Not bashing the scope - it will work great for some people.  But most people are not looking for such a scope, and that reduces its value substantially.  It is like selling a home with pink carpet, floral wall paper, gold hardware, and a closed-floor plan.  Fine in the 70s, but not now.  And the servocat is like saying "but the home has a nice furnace! that's worth a lot!"  People don't value things like that.  

I sure never see them in FL and if it was local i would sell my soul.  No way i would set it up and break it down just to view a planet each nite. But if it could roll thru my narrow back door it would be a killer planet scope. Just roll it out do a fast collimation touch up let it cool or heat up since more scopes gotta heat up where i live, plop in a 3mm Delite and enjoy gulf ball size images of planets in my steady seeing.  If it only fit in the Vette.  I am temtped to offer him 1k to bring it to me.


Edited by CHASLX200, 12 November 2018 - 07:06 PM.

 

#50 George N

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Posted 13 November 2018 - 11:39 AM

……..  I see people all the time list all the retail prices of the additions they have, and then add it all up.  But human beings don't value items as the sum of their parts.  They (properly) value them as a whole.

 

….

That's why, 'back in the old days' Don Yeier (of VERNONscope fame) - for his antique scope and instrument auctions - would buy old scopes from estate sales, etc, and break them up into parts to auction off separately. He didn't do that with Unitron, Questar, or god-forbid Clarks..... but with most lesser scopes he did - and made a lot more money that way. He tried it both ways.... and auctioning parts produced more $$ than auctioning complete old telescopes.

….and yet to me.... a scope like an old Obsession 'classic' is more desirable with certain options added. They are 'the little things' that make a very good scope a great scope to observe with. I'm talking things like the common sliding counter-weights, improved cooling fans, dew control, modern encoders, Glatter sling, filter slider, wires inside the truss poles, or the poles used as conductors, high-end focuser, maybe a stalk for your iPad, even an optical finder, others??. For some - a professionally installed StelllarCat is a big benefit versus a half-baked install. One of the 'advantages' of buying used is - you don't have to do all the work yourself - and you will still save $$. While installing most of these items is within the abilities of most owners - why bother if you can get a scope already mod'ed? You avoid all the hassle of finding the 'upgrades' for sale, waiting for shipping, finding an afternoon and work space (setting up an Obsession 20 F/5 to work on under a 6 foot ceiling is not easy - take my word for it! )  This of course assumes that the person who did the work did it correctly.


Edited by George N, 13 November 2018 - 11:44 AM.

 


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