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The 22" Obsession Ultra Compact


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22inch UC
22" Obsession Ultra Compact
Tom Trusock
10/09


Ok, so I've got a new scope to lust after.

It's been a while since I've personally been interested in a large telescope.  I mean a good observing buddy has a 30” Obsession, and I've got an 18” in my private observatory so lately when I've been heading to star parties I've either been taking a small telescope or relying on other folks to bring the big guns.  While I spend a LOT of time with smaller scopes, there's no arguing that aperture will simply show you more.

But I've never been all that tempted by anything bigger than my 18”.  I mean, lets face it – big telescopes are an exercise in logistics.   You have to transport them, store them and – don't forget – set them up.  If you're headed out by yourself, well – this task isn't exactly impossible, but it's not a particularly simple operation.  (Think winches, tackle, ramps, trailers and teams of slaves…)

Dave Kriege's Ultra Compact scopes go a ways towards eliminating some of these hassles.  The first out of the gate was the 18”, and that was a wonderful option in a super compact and portable large aperture.  Especially for those of us who say - aren't as handy as some of the ATM'ers out there.  (Me, I hardly know which end of the hammer to hold.) Still, let’s be frank: nothing's going to be the ticket for everyone, and the ultra compact / ultra light design isn't without a few trade offs.  Hence Obsession's still booming market for what are now referred to as the “Classics”.  (FWIW, Dave Kriege recently remarked that sales are split pretty evenly between the UC and the Classic models.)  

Fast forward a year, and we see Obsession introduced a 15” UC for those that are looking for something a little smaller and less expensive than the 18”.    The 15” UC really tempts me.  It would be a fantastic little star party telescope, but my personal funding levels being what they are right now, well it's going to have to wait a while.

Not to mention my heart's been stolen by the latest iteration – the new 22” UC.

I spent a recent weekend in Michigan's Upper Peninsula at one of my favorite dark sky sites and had an opportunity to spend some time with Dave as well as play with his latest toy.

This scope is pretty much the evolution of the design, and has the features that you'd expect – at least for the most part.  There are also some additions: like 8 poles instead of six.  This adds to stability (a nice and needed touch for a larger telescope), but functionally – well – it's an Obsession Ultra Compact. 

Collapsed the base is about 28”x29”x18” high, with the heaviest component around 90 lbs.  The f4.2 mirror alone weighs around 65.   Its eyepiece height at zenith is around 88 inches, putting it significantly shorter than the 20” F5 that's been so popular over the years.  And for me, it’s just about perfect.   But more on that in a bit.



The scope is rather deceptive – with the shroud off, it really does not look like a 22” inch telescope.  I mean those are BIG scopes.  No, this had a physical presence more like an 18” incher.  The scope was solid, and well balanced (able to take heavy and light loads with aplomb).  Settle time was minimal, and tracking was smooth.    Setup is about the same as the others in the series at 5-10 minutes including collimation.   I've got a video on the site of Dave putting one of the other UC's together if you're interested.
 
The OMI mirror delivered what I've come to expect from OMI – a top of the line viewing experience.  

There's always an argument about Paracorrs.  Do I really need one?  Personally f5 is the breaking point for me, but many amateurs get down to f4.5 before they feel the need.  The 22” is an f4.2.  You will want a paracorr.   I could definitely notice the difference with one in.   

Using the 22” was an experience.  Most of our observing was done flat footed, but there were a few targets that we had to go “up” for.  But even then – it was only a step or two up a standard step ladder – no huge ladders required here.     The scope was fairly stable in a 20-25 mph wind.   While it did weathervane a bit (completely expected given it's smooth motions), the scope remained stable enough to use, and only when the strongest gusts came through was any vibration evident.  

Some users have noted that there appears to be a noticeable “bump” when moving the scope over the hinged point on it's alt bearings.  I don't know if Dave addressed that, if the added mass takes care of it, or if we simply weren't observing in portions of the sky where we'd notice it – but it just wasn't an issue for me. 

While 22” isn't “that” much larger than my own light bucket, the difference in views were evident and obvious – not in part because of the location of the 22 inch (that place is black as pitch!).  But you see, that's what the Ultra Compacts excel at.  Portability.  On the flip side – while any truss dob is portable, my 18” will probably never leave my observatory again and while my skies are good – that aren't THAT good.   



The one clear evening we had, the weather was a little sporadic at best and we found ourselves observing through breaks and sucker holes.  Every so often the sky would clear off completely, and when it did – WOW.    Observing with a large scope is always a treat, but observing with a large telescope at one of the darkest sites this side of the Mississippi, and with the transparency that comes through after a storm – well, that’s just a jaw dropping experience.    And to add to it – we also had a sample of the new 21 Ethos available for use.  That eyepiece pretty much just stayed in the focuser all night.  The combination of TFOV and magnification were stunning.  It had a wide enough real field that we were able to use it as a finder, but provided enough magnification that we weren't all that tempted to switch it out for a different eye piece.

The 22” UC comes with a FeatherTouch, Telrad, External Light Baffle, CounterWeight system, and wheel barrel handles.    I'd highly recommend adding – at the least - a light shroud (also known in Michigan as a “dew shield”), ParaCorr and an Argo Navis system to make the most of your time under the extremely dark skies your portable new telescope will allow you to reach.    



At a price of $9995, I don't think any one would ever call it cheap, I do think it's a reasonable price for a 22” telescope – especially in this post pyrex world that’s careening towards us.  If transport is a question, then it's most CERTAINLY worth a look - assuming you're in the market for a large scope.

You know the phrase “Think Happy Thoughts?”  Well, I can tell you a 22” scope under ultra dark skies generates plenty of those.  I know it's got me thinking.  Unfortunately I suspect my wife isn't going to like the direction.


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