Home / The 22" Obsession Ultra Compact
by Tom Trusock 10/12/09 | Email Author Voice your opinion about this topic in the forums
22inch UC
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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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