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Re: third light - ZSFD

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  • Ian King
    I was unable to detect any ring divisions. I don t think this is too surprising. It is only a 3 inch scope.--- In William- Optics@yahoogroups.com, Graham
    Message 1 of 2 , Jan 5, 2006
      "I was unable to detect any ring divisions. I don't think this is too
      surprising. It is only a 3 inch scope.--- In William-
      Optics@yahoogroups.com, "Graham Rhodes" <grhodes@n...> wrote:"



      Graham

      Nice report - Cassini division though is an easy spot with the ZS66
      and ZS80 - just takes a bit of practice.

      ATB

      Ian

      Http://www.IanKingImaging.com



      >
      > Hi All,
      >
      > This is a rambling, casual third light report, for my new WO ZSFD
      red
      > scope. Twice before tonight I was able to find time on clearish
      nights
      > to gaze upward, but only for about 10 minutes each time due to the
      sky
      > becoming cloudy and family obligations during the holiday evenings.
      >
      > The new scope is my first "real" (well, "real good") telescope, the
      > prior one being a cheap refractor owned as a kid. I don't remember
      > seeing anything but the moon through that one. It is long lost and
      > forgotten. My observation skills are not developed! And, so, I
      won't
      > try to give any detailed analysis of the optics, etc. Just what
      > equipment I used, what I saw, and some ideas I have about optical
      issues.
      >
      > Tonight, here in my urban backyard in Raleigh, NC, skies haven't
      been
      > fantastic for viewing. (Clear skies since the scope arrived have
      been
      > exceedlying rare, as expected.) I just came inside, around quarter
      > till 1AM. The clear sky clock lists transparency as too cloudy to
      > forecast, and bad seeing, with only occasional pockets that aren't
      > covered by clouds. And that prediction seems consistent with what I
      > experienced. But, I was able to see what I wanted to see!
      >
      > I didn't expect an opportunity to observe. But, about 2 hours ago I
      > poked my head out and saw a few stars. Enough clear spots that I
      > thought I might be able to spot Saturn. And so I set the scope up.
      I
      > spent about an hour observing, only occasionally steering away from
      > Saturn (which I guess is the "star" of the skies this month).
      >
      > Equipment was the ZSFD red scope, a Stellarvue M1 alt-azimuth
      mount on
      > a Manfrotto 3021 pro tripod, a WO 6x30 finder scope, and 3
      eyepieces:
      > a 25mm WO SWAN, a 12.5mm Celestron X-Cel, and a 4mm Burgess
      Planetary
      > eyepiece. Oh, and a wrought iron lawn chair, brought into service
      when
      > I got tired of sitting on my knees.
      >
      > I am not finding the finder scope to be terribly useful. I have
      found
      > that I have difficulty mounting it to the scope securely enough
      that
      > it stays aligned. A small locking/alignment pin for the finder
      mount
      > would be an *extremely* welcome feature (really, I mean it). The
      > finder has helped a bit, but I have also found it awkward to peer
      > through. I'm thinking a red dot finder may be a bit nicer, but
      when I
      > ordered the scope I was looking for a more traditional-looking
      finder
      > scope. Perhaps I don't even need a finder scope, and can simply use
      > the 25mm SWAN for locating objects. Oh well, I am learning.
      >
      > I am somewhat familiar with the Orion complex, and was able to use
      > Betelgeuse as a starting point to find Saturn (once it rose above
      the
      > mature pine trees in my back yard).
      >
      > The 25mm WO eyepiece is very nice, in my opinion. Well made, to be
      > sure. Wide angle, very bright and (to my eyes) sharp views. It is
      big
      > (but, I'm guessing, not as big as a similar Nagler?). In this
      > eyepiece, @ 22x, Saturn looked kind of like a smudged star. I was
      not
      > able to distinguish the rings. I suspect that I might be able to
      > distinguish the rings in dark skies with better seeing and a more
      > stable mount (more on the latter later).
      >
      > With the 12.5mm Celestron, @ 44x, the planet was a bit larger, and
      > only slightly dimmer. Here, I was able to separate the rings from
      the
      > disk, but only by carefully allowing the vibrations to settle. This
      > was tedious. I had to be sure to hold my head away from the
      eyepiece
      > to avoid exciting another vibration. This was the first time in my
      > life that I have seen Saturn live in person, and it won't surprise
      you
      > that I found it breathtaking.
      >
      > With the 4mm Burgess eyepiece, @ 138x, the planet was larger still
      (no
      > duh!), and noticeably dimmer. But still quite bright. Again, I had
      to
      > wait for the vibrations to settle, but because of the enlargement I
      > actually found it easier to hold on to the visual separation
      between
      > disk and rings. Even with quite a bit of vibration during
      settling, I
      > never lost my hold on the separation.
      >
      > I was unable to detect any ring divisions. I don't think this is
      too
      > surprising. It is only a 3 inch scope. Transparency and seeing were
      > not particularly good. And, skies here are not particularly dark.
      With
      > the 4mm Burgess, I was unable to achieve a tack sharp focus on
      Saturn.
      > That could have been due to seeing, etc. I also was unable to
      achieve
      > a tack sharp focus on stars with the 4mm, but was with the other
      two
      > eyepieces. Which, I believe, suggests that the distance from
      primary
      > to eyepiece might not have been sufficient. At this point, I
      believe
      > the objective lens was beginning to fog up a bit, and that too
      could
      > have caused perceived focus problems. Next time, I think I'll try
      to
      > lock the eyepiece in place slightly above its well-seated
      position, to
      > see if I can achieve better focus. Still, the focus I achieved on
      > Saturn was about what I expected, based on various astronomy books
      > I've been reading. The planet was bright enough and large enough
      that
      > I think it might be possible to detect (if only by averted vision)
      the
      > Cassini division at a dark site with good seeing through the 4mm.
      >
      > I was not able to really detect any surface features on the disk.
      > Again, I don't think this is too surprising. The planet was large
      > enough and bright enough that I might see something at a dark
      site, or
      > with more practice observing.
      >
      > I am learning a few things here. Things that I've read about, but
      > haven't experience first-hand until now. My house is located
      > prominantly at the front of the main drag through the neighborhood.
      > Its a show home spot. There are street lights up front. I have 1/4
      > acre lot, with mostly front yard. We like trees here. Big ones. I
      > decided to set up in back, since the back yard is more in shadow
      from
      > the street lights. But, the trees are all 50+ foot pines. And the
      back
      > yard is small. And, there is a deck. If I set the scope up in the
      > yard, I would only be able to see things at zenith. The deck gets
      in
      > the way. So, I decided to set the scope up on the deck, to have a
      > wider altitude range. With the combination of: a) the scope on a
      > wooden deck; b) Manfrotto tripod holding its absolute max weight
      limit
      > (actually a bit more); and, c) tripod center-post extended about
      half
      > way to enable the mount to look close to zenith, I found that I had
      > quite an unstable setup. Very little risk of the tripod toppling
      over,
      > but we're talking 10 seconds (TEN seconds) for vibrations to
      settle. I
      > believe that is quite poor! The scope was balanced fairly well on
      the
      > mount. But the M1 mount doesn't seem to have a mechanism to
      support a
      > counterweight on the other side. That could be an issue, I think.
      Some
      > similarly-styled alt-azimuth mounts provide a way to add a
      > counterweight bar... For those who want details, I had only
      extended
      > one set of tripod leg segments, and those were extended fully.
      And, as
      > mentioned above, the center post was half way up. In this
      > configuration, I found observing to be extremely comfortable in the
      > lawn chair for objects near zenith. Without the chair, I was on my
      > knees. For objects nearer the horizon, it was comfortable enough
      to stand.
      >
      > About the Stellarvue mount...I will try to post more about over @
      > Cloudy Nights, in the Mounts forum, soon. I'll also try to find
      time
      > to take some photos and put up on my web site (www.gsrhodes.com),
      on
      > the telescope page. For now, I will just say that it is very well
      > made, appears sturdy and capable of holding the scope stably. I do
      not
      > have any real belief that a counterweight would help with
      stability in
      > my setup. I believe my stability issues arise from the tripod and
      deck
      > far moreso than the mount. That is not to say that I don't have
      some
      > (extremely minor) issues with the mount. I won't say more about
      this
      > until I've had time to take some photos and think about it further.
      >
      > Graham
      >
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