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Thread: Good Viewing conditions

  1. #1
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    Good Viewing conditions

    I'm curios to know what the ideal viewing conditions are ? Right now I have very good transparency, and Humidity is at 26%. However, the winds are very high and gusting up to 46Kmh

  2. #2
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    Quote Originally Posted by Adamsavage View Post
    I'm curios to know what the ideal viewing conditions are ? Right now I have very good transparency, and Humidity is at 26%. However, the winds are very high and gusting up to 46Kmh
    Ideal viewing conditions: Maybe a couple light years away from the sun... Seriously though, high winds usually wreak havoc on seeing, all that moving air is very unstable. Not to mention the stability issues high winds present to many if not all scope mounts. How are the stars? Twikling a lot or relatively calm? Good transparency is not unusual during high winds because all the crud in the air that hurts transparency is getting blown somewhere else. However, all that moving air is really unstable and will affect seeing significantly.

  3. #3
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    I went out after making my post and the wind was just causing havoc on the viewing. When I did manage to focus on Jupiter, it was dancing all over the place in my eyepiece. Even then I couldn't really get a good focus on it, using the Barlow made things even worse. I tried again just now on mars with just my 8mm eye piece and I couldn't focus on it. The wind is just racing, and where I was viewing I'm sheltered from the worst of the winds. I can only imagine how fast it is higher up.

  4. #4
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    Quote Originally Posted by Adamsavage View Post
    I went out after making my post and the wind was just causing havoc on the viewing. When I did manage to focus on Jupiter, it was dancing all over the place in my eyepiece. Even then I couldn't really get a good focus on it, using the Barlow made things even worse. I tried again just now on mars with just my 8mm eye piece and I couldn't focus on it. The wind is just racing, and where I was viewing I'm sheltered from the worst of the winds. I can only imagine how fast it is higher up.
    That sounds pretty consistent with poor seeing.

  5. #5
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    What is a good combination of both transparency, humidity and seeing conditions ?

  6. #6
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    Low humidity is always a plus, icy or foggy optics are no fun. Transparency and seeing (turbulence) can be influenced by so many factors (near and far) that the only generally true thing one can say is that good conditions are good conditions. As an example on one of the best nights I ever had (that rare combination of excellent seeing and transparency) we had a thin but persistant ground fog.

  7. #7
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    In my experience, the perfect combination of good transparency and good seeing is a rare occurrence around here. I have seen sparkling clear skies that gave a great view of faint deep sky fuzzies and wide double stars at low to medium magnification, but were ghastly for trying to observe the surface of a planet at high power. I have seen murky conditions that dimmed everything by a couple of magnitudes but gave sharp, rock steady views of Jupiter and Saturn at high power, along with double stars near my telescope's resolution limit. These objects were bright enough that the loss of brightness did not hurt. Then I had a rare summer night when it was warm and humid but uncharacteristicly free of haze, and steady on top of that. I had a clear view not only of the stars overhead, but also a line of thunderstorms about 100 miles to the south. The lightning was going almost continuously. What we had was a fresh mass of pure tropical air from the south which had pushed out the murky stuff and had given us a calm before the storm. The next day those thunderstorms were upon us.

  8. #8
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    Quote Originally Posted by Adamsavage View Post
    What is a good combination of both transparency, humidity and seeing conditions ?
    Good conditions are highly dependent on local conditions, weather patterns, even the season. In my neck of the woods, both seeing and transparency are pretty lousy all through winter and spring. We get lots of frontal systems coming through (bad for seeing) and lots of humidity (bad for transparency). Add to that the necessity of finding a spot away from light pollution, which isn't easy when you live 15 miles from a major city. During summer, there is about a one month window when the seeing/transparency can be quite good - as good as when I had my scope in Arizona.

    Best seeing/transparency I've ever experienced: Great Basin National Park - awesome combination of high altitude (9000 ft.), VERY dark sky (closest town of any significance is 60 miles and two mtn. ranges away), and dry, stable air. Those are the ingredients for good observing conditions, provided the dry air isn't also ridden with dust.

    I have no idea what the local conditions are like in your area, this is where joining a club is essential. Experienced observers in your area should be able to tell you all you need to know about your local conditions - what time of year the seeing tends to be better, etc.

  9. #9
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    Quote Originally Posted by redshifter View Post
    Good conditions are highly dependent on local conditions, weather patterns, even the season. In my neck of the woods, both seeing and transparency are pretty lousy all through winter and spring. We get lots of frontal systems coming through (bad for seeing) and lots of humidity (bad for transparency). Add to that the necessity of finding a spot away from light pollution, which isn't easy when you live 15 miles from a major city. During summer, there is about a one month window when the seeing/transparency can be quite good - as good as when I had my scope in Arizona.

    Best seeing/transparency I've ever experienced: Great Basin National Park - awesome combination of high altitude (9000 ft.), VERY dark sky (closest town of any significance is 60 miles and two mtn. ranges away), and dry, stable air. Those are the ingredients for good observing conditions, provided the dry air isn't also ridden with dust.

    I have no idea what the local conditions are like in your area, this is where joining a club is essential. Experienced observers in your area should be able to tell you all you need to know about your local conditions - what time of year the seeing tends to be better, etc.
    I did join one club, but I started a new Job that prevented me going to the meetings. I believe there is another one coming soon, and I have access to observing sites but I would still need a way to get there. I could post a message in the group and ask if anyone could bring me along with them. Still using my 5 inch scope for now, I'm thinking of renting the 8 inch dobo scope to see what it's like as well.

  10. #10
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    I second redshifter's comment about local dependence. It took me years to really get the fact that in the southeastern US, the calmest seeing is often found on very hot, uncomfortably humid nights. All that water vapor with its ridiculous heat capacity slows convection and makes the low-level air very stable. Pretty much the opposite of the weather patterns in the drier western part of the continent (and often separate from good transparency).

  11. #11
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    From my own observing site.. things are not ever perfect.. Only a few km from the Tasman sea..

    On a alluvial plain in central western New Zealand. 175.. E & 39.. S.

    and a constant moister ridden sky.. when it's not cloud covered... or windy.

    BUT despite that gloomy description we have a very well equipped observatory

    and a membership of twenty or so active members.. most with their own equipment.

    We venture away from the city lights to a countryside location and we get a great view..

    All that I am endorsing is that..You can adapt to your conditions.. enjoy...

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