Re: Can you see Pluto in a 4 inch scope?
> I believe Derek _thinks_ he saw Pluto. Sometimes I wonder: whenOK, I'm here to be ridiculed. But before I get trashed too much, let
> people spend ~$2500 on a 92mm scope (assuming he bought new, and
> didn't pay the crazy premiums these scopes are going for used), how
> much the desire to rationalize the purchase contributes to the well
> known effect of "averted imagination."
me say that I saw Pluto with a Guide chart enhanced with USNO A 2.0
data. The observation was made well away from the scope field, at
150x by using hyperventilation to fight the effects of high altitude
and covering my eye until the staring into the eyepiece. Pluto was
visible about 30% of the time, and this observation was over at least
twenty minutes after I found the field.
I confirmed the observation with the 7" Teleport the next night. I
had trouble in a brief glance in the 14.5" because there were too
stars, and in the 18" must have been a pain. Also, I am nowhere near
the observer that some people like Jay Freeman, etc. are.
Please see the following:
1. Todd Gross' webpage www.weatherman.com under 60 scope reviews,
which is the Tak 76. Todd suspects the 13th mag star near M57 with
this scope. I actually think this star is a lot brighter than mag 13
(don't believe the GSC, as these values can be way off). But I
believe Todd observes in quite a bit of light pollution.
2. I can't access the deja archives. However, Jeff Medkeff, an S+T
contributor saw 14.5 or thereabouts with a 4.5" reflector. Jeff had
50% more light gathering power but saw a star over twice as dim as
Pluto. Is Jeff lying? Well, it's too bad the storm over that
observation is unavailable, but the thread went on quite awhile.
3. Contact Brian Skiff the professional astronomer and extremely
respected observer. He saw Pluto with a PRONTO, in darker mag 7
conditions. Yes folks, a 70mm semi-apo. Do you think he is
4. Don Pensack, one of my mentors and with 30 years observing
experience saw mag 15.9 small galaxies with his 8" SCT. Again, do
5. See the Observer's Page, S+T April 1994 P. 106-108 by Roger Clark.
This gives an estimate of limiting magnitude in percentages. Here is
some info for 3-4" scopes:
98% 90% 50% 20% 10% 5% 2%
3" 12.1 12.6 13.1 13.6 14.1 14.8 15.6
4" 12.7 13.2 13.7 14.2 14.7 15.4 16.2
If we interpolate, then you can see that the a 3.64" scope is right
between the 20%-50% level of detection. And no, I didn't review this
Someone commented on Stephen O'Meara. Well, his observations as well
as Barbara Wilson's are on the order of the 2% level, ie. mag 15.6
with a 3" scope. The same article above says that O'Meara saw
Halley's comet at 19 mag with a 20.4 mag field star with a 24", which
is equivalent to mag 17 with a 6" (at the 2% limit of the chart).
This is in a completely different league.
OK, now about spending a ridiculous amount for a 92mm scope--yes, it
is expensive, but I didn't pay as much as for a Questar. I am under
no illusions about the limitations of aperture. The sharp refractive
objects do give it some advantage over other kinds of scopes of
3.5-4.5" aperture, but the 7" Teleport trashed it on DSO's (and would
on planets also).
I would advise everyone to at least test their abilities by trying
of Jay Freeman's techniques on the TAC webpage, listening to Jeff
Medkeff's limiting magnitude talk, then observing with experienced
people and trying crazy things yourself. You will be amazed. I have
a long way to go, as Jeff, Jay, etc. are at least a half magnitude
deeper than I.
When I observed Himalia with my 12.5" I was careful to get a
confirmation from a gentleman named Czernic Crute. Next time I will
try to get someone to confirm an observation such as this, but most
people don't want to spend a half hour with an eye patch over one eye
just to get a few averted vision glimpses of some dim point.
By the way, my next bit of fabrication will be to try to observe
with a 10" from my house with limiting mag 4-4.5. I already imagined
that I did it with my 12.5", who knows what I can dream about now?
Happy averted imagination,
> me say that I saw Pluto with a Guide chart enhanced with USNO A 2.0altitude
> data. The observation was made well away from the scope field, at
> 150x by using hyperventilation to fight the effects of high
> and covering my eye until the staring into the eyepiece. Pluto wasleast
> visible about 30% of the time, and this observation was over at
> twenty minutes after I found the field.Hi Derek,
Thanks for the info on observing tricks, not intended but useful for
me (I have only about 9 months in this hobby). Also for the info
about the importance of good seeing, dark location, good eyes, and
potential of small telescopes.
Impresive equipment you have!
I own a cheap 6" reflector and a TV Ranger that I use most for nature
If I stay in the hobby I might go for a good scope. Any suggestions?,
I am more of a DSO guy. How is that 7" Teleport? any problems?
Is that 92mm a AP Stowaway? if it is, you have a dreamscope! lucky...
Thanks again, and clear skies,
- --- Chiang Ma wrote:
> Impresive equipment you have!Hi Chiang:
> I own a cheap 6" reflector and a TV Ranger that I use most
> for nature study.
> I am more of a DSO guy. How is that 7" Teleport? any problems?
> Is that 92mm a AP Stowaway? if it is, you have a dreamscope!
The Stowaway is a great small scope, but if that 6" has any figure at
all it will kill the Stowaway on DSO's.
The Teleport IS a dream airline portable scope. The mirror got
up during transport and needed to be recollimated, but otherwise
everything was OK. The optics were VERY nice. I'm little more than
beginner at the star test but this was one of the best I've seen.
mechanics are good. You would need a stool or flexible legs to
observe comfortably. By the way, I just heard on s.a.a. about one
disadvantage of the 10" version--they are easy to steal, and Tom's
show scope was stolen :-(
However, if you are a DSO person and can handle a big scope, for
I would keep the Ranger, sell the 6" and buy a 12.5" or 15" f/5
Discovery scope. That would get you some awesome views of many
not to mention the planets.
- --- In firstname.lastname@example.org, "Derek Wong" <dawong@e...> wrote:
> OK, I'm here to be ridiculed. But before I get trashed too much...
Glad you're here to defend yourself! Sorry if you took my posts as a
slam...I thought my first reply was too heavy handed, which is why I
came back a second time to make clear I didn't think you were
fabricating, at least not consciously. At worst, I thought you might
be guilty of a little self-deception, to which I have fallen prey
often enough myself.
All your references from some very credible and experienced people
suggest that I am probably too closed-minded on this subject. I
based my skepticism on my own experience (I'd call myself
an "intermediate" observer) in hunting faint planetaries and galaxies
in my 12.5." Perhaps this experience is not directly applicable to
the detection of stellar objects in a smaller aperture. There is
also the possibility that you and the other folks cited may be
(gasp!) much better observers than me.
As for the cost of the Stowaway, relative to the Questar, I don't
think that's the way to show value! :-)
Anyway, hope there are no hard feelings, as no slam was intended. If
you did see Pluto, then congratulations! Despite all the citations,
forgive this poor narrow-minded soul who cannot let go of his
skepticism, and wants to say: "Show me!" Though of course in these
kinds of cases that's impossible. I guess imagers don't have these
kinds of arguments!
Good luck with your future challenges!
> However, if you are a DSO person and can handle a big scope, forYes, I can handle a big scope.
> I would keep the Ranger, sell the 6" and buy a 12.5" or 15" f/5
> Discovery scope. That would get you some awesome views of many
> not to mention the planets.
I was looking at the Starmaster 12.5" EL. Do you know how this one
considering that it has a Zambuto mirror compares to a 12.5"/15"
Discovery? I mean in optical performance for DSO's. Will a Z mirror
make a big difference? (in price it makes a big difference).
I ordered a 10" Discovery ($569) 2 months ago with a delivery
time of 45 days; I have not received it and for the posts I have read
about their inconsistent delivery times I am not expecting to receive
it in a very close future, if I ever receive it. I might just cancel
I ordered it just to see how big of a difference it is vs my 6" and
probably jump later to a better quality/bigger scope. Also I just
received the Obsession video and I am impressed (obsessed?).
About selling my 6", well... that is my first scope and I love it. It
is strange that depending on my mood I use the ranger, the 6", or
just the binos; maybe I am the type that needs a bunch of different
Thanks in advance for any input,
- --- In email@example.com, amanguy61@h... wrote:
> Yes, I can handle a big scope.I have seen but never used the Discovery trusses, so I will speak in
> I was looking at the Starmaster 12.5" EL. Do you know how this one
> considering that it has a Zambuto mirror compares to a 12.5"/15"
> Discovery? I mean in optical performance for DSO's. Will a Z mirror
> make a big difference? (in price it makes a big difference).
When you get a premium Dob like a Starmaster, there are some very
--The mirror cell is a work of art, and supports the primary in a
fashion that prevents stresses at different angles.
--The fit and precision is excellent. The collimation will not vary
much if you tip the scope, very important with fast dobs.
--Thin mirrors 1.6" aid cooling
--You can order a Feathertouch focuser, which makes observing a joy.
--Service is excellent. Rick and Carol get calls on Saturdays at
and are more than happy to answer questions.
In these scopes, mechanical precision is at least as important, if
more important as the mirror figure (assuming the mirror isn't a real
dog). You may have a great mirror, but if the scope sags a couple
millimeters, the mirror is not supported well or the scope has a long
cooldown then you will not be diffaction limited even in the center
On DSO's, a scope which is superior optically and/or mechanically
show a better view on all objects, especially globulars, dust lanes
galaxies, detail in planetaries, etc. Also, when after you see
Jupiter you won't want to confine yourself to DSO's :-)
> I ordered it just to see how big of a difference it is vs my 6" andForget about an intermediate scope, get the one you really want.
> probably jump later to a better quality/bigger scope. Also I just
> received the Obsession video and I am impressed (obsessed?).
Obsession also makes wonderful scopes. There is a big debate, but
what sold me on the Starmaster was the GOTO/tracking system.
> About selling my 6", well... that is my first scope and I love it.It
> is strange that depending on my mood I use the ranger, the 6", orTalk to Todd Gross :-)
> just the binos; maybe I am the type that needs a bunch of different
> scopes :-)