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Brian Howell
登録日: 2006.05.22 記事: 39
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SonotaCo Site Admin
登録日: 2004.08.07 記事: 12653 所在地: 139.67E 35.65N
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日時: Mon Nov 19, 2007 9:39 am 記事の件名: Re: Neptune 100 or Watec 902H2 Ultimate |
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Hi
In my experience, the basic sensitivity is almost same. But 902H2U has a bit better S/N.
http://sonotaco.jp/forum/viewtopic.php?t=1041
100N needs to connect remote control cable, but 902H2U has all switches on its body.
902H2U is also capable to set gamma off (=1.0).
100N has unique auto iris pin assignment, while 902H2U has standard EIA pin assignment(both video and DC iris lens can be used).
Therefore I am now recommending WAT902H2 Ultimate for all observers.
I don't know the third cooled camera. It may be possible to reduce noise by cooling.
But there may be many delicate problems, such as duw by cooling.
I know no one who uses such cameras so far.
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Brian Howell
登録日: 2006.05.22 記事: 39
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日時: Mon Nov 19, 2007 11:00 am 記事の件名: |
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It looks like the 902H2U is a winner. The good thing is for once the better camera is half the price.
Thanks
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Lightningwizard
登録日: 2007.10.19 記事: 165
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日時: Tue Nov 20, 2007 11:42 pm 記事の件名: |
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The cooled Astrovid would be nice, but is priced really high... you can get 3 Watec 902H2 Ultimates for that.
The sensitivity of the 100N I have seen (but not in direct comparison) is lower than the Ultimate, so it needs more gain for the same magnitude. I would get it only if the remote control is important to you.
The 902H2 Ultimate has manual gain and gamma settings which you will like, and its mount is wide enough for the F0.8 lenses to fit with the IR correction lens mounted (the Supreme does not allow this). The gamma off setting looks better in a city when the sky would be light-polluted. In a very dark area I would leave it at the normal setting and tend to increase the gain, because the amount of stars you see with your eyes becomes much larger than the camera sees at my typical city settings. But sprites don't need much gain with the Ultimate and bright ones can overexpose at AGC LO setting. For meteors you probably want the best detection rather than best image quality, perhaps it matters less.
By the way, Computar stopped production of the F0.8 lenses a few months ago, so they may become harder to get. It could be interesting (for sprites) to get a F1.2 zoom lens.
I bought my Watec 902H2 Ultimate and 12mm F0.8 lens at
www.reytecimaging.com
Happy shopping
Oscar
_________________ Weather & Photography
http://www.lightningwizard.com
EuroSprite blog:
http://eurosprite.blogspot.com |
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SonotaCo Site Admin
登録日: 2004.08.07 記事: 12653 所在地: 139.67E 35.65N
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Brian Howell
登録日: 2006.05.22 記事: 39
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日時: Wed Nov 21, 2007 11:23 am 記事の件名: |
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Thanks for the info Lightningwizard.
I have trees around my house on all sides but would like to use a lens that would give me a field of view that covers as much of the sky that is visible. I may need 90
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SonotaCo Site Admin
登録日: 2004.08.07 記事: 12653 所在地: 139.67E 35.65N
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Brian Howell
登録日: 2006.05.22 記事: 39
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日時: Wed Nov 21, 2007 12:47 pm 記事の件名: |
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Thanks SonotaCo this helps a lot. I'll try to see if I can find some good sources for lenses.
I'm also going to try to figure out the best way to house the camera outside. I don't know if direct sunlight all day would hurt the camera if I were to put it under a transparent plastic dome. I wonder if I could buy or make some kind of automated cover for the dome to protect the camera from the sun.
Brian
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SonotaCo Site Admin
登録日: 2004.08.07 記事: 12653 所在地: 139.67E 35.65N
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日時: Wed Nov 21, 2007 1:13 pm 記事の件名: |
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Brian Howell wrote: | I'm also going to try to figure out the best way to house the camera outside. I don't know if direct sunlight all day would hurt the camera if I were to put it under a transparent plastic dome. I wonder if I could buy or make some kind of automated cover for the dome to protect the camera from the sun. |
I am using normal camera housing for a few years.
Under the calm crimate of Tokyo, those cameras are still alive.
But I am not sure for your case.
wb6mcw has reported his nice housing with fan below.
http://sonotaco.jp/forum/viewtopic.php?t=1102
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Brian Howell
登録日: 2006.05.22 記事: 39
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日時: Thu Nov 22, 2007 8:29 am 記事の件名: |
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Thanks again for the info SonotaCo. Where I live the weather is usually pretty calm. A regular housing may work for me as well. I don't know if it would interfere with a wide field lens though.
Is it possible to buy or use a large diameter lens such as from a camera to gather more light instead of the small lenses people are currently using.
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SonotaCo Site Admin
登録日: 2004.08.07 記事: 12653 所在地: 139.67E 35.65N
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日時: Thu Nov 22, 2007 11:08 am 記事の件名: |
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Brian Howell wrote: | A regular housing may work for me as well. I don't know if it would interfere with a wide field lens though. |
3.8mm lens may be the limit for housing that has flat glass. Did you see http://members.aol.com/lx90images/skycam.html ?
Brian Howell wrote: | Is it possible to buy or use a large diameter lens such as from a camera to gather more light instead of the small lenses people are currently using. |
The fastest lens that is in market is F=0.8 that we are using.
It is not easy to gather more light from wide view.
That might be possible by using fish eye lens for 35mm still cameras and image intensifier and relay lens. I don't know how much it costs .
Cheers
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Brian Howell
登録日: 2006.05.22 記事: 39
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日時: Thu Nov 22, 2007 11:31 am 記事の件名: |
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SonotaCo wrote: | Brian Howell wrote: | A regular housing may work for me as well. I don't know if it would interfere with a wide field lens though. |
3.8mm lens may be the limit for housing that has flat glass. Did you see http://members.aol.com/lx90images/skycam.html ? |
I was just looking at that. Something similar to that may be what I'm looking for. I would probably want to be able to cover it up automatically when the sun comes up, especially in the summer, the sun can be harsh. We had a few weeks this past summer that got up into the low 100's Fahrenheit. I also wouldn't want the lens cooking CCD chip.
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