Author Topic: stars  (Read 2223 times)

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Offline didispeed

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    • didispeed
stars
« on: May 19, 2009, 07:24:54 PM »
Hey, does anyone know how to take
good pictures of the stars in the sky?

I saw the milky way galaxy in France on a very
bright night, but was not able to take a descent picture of it.

How do you do it, exposure, wide angle?, Zoom?

Please let me know, thanks
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Offline MikeO

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Re: stars
« Reply #1 on: May 19, 2009, 08:03:26 PM »
Generally for star photography you need long exposures. How long depends on the magnitudes of the stars you're trying to photograph. The problem is that when you do long exposures of the sky the stars move. Thus you need a star-tracking mount. I believe Meade makes some fairly decent low end telescopes that can track stars. Under $1000. You'd still need to get the mounting adapters for it though.
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Offline zamri

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Re: stars
« Reply #2 on: May 28, 2009, 08:51:33 AM »
Hi, you still able to shoot the milkyway by using a wide angle lens with a fixed tripod. You need to shoot a few frames then stack them together.

Here the Approximate Exposure Times for No  Star Trailing

50 mm Lens
Star Declination Exposure
0 degrees (on the celestial equator)                  8.5 seconds
30 degrees (60 degrees from the celestial pole)  12.5 seconds
60 degrees (30 degrees from the celestial pole)  25 seconds


24 mm Lens
Star Declination Exposure
0 degrees (on the celestial equator)                  17 seconds
30 degrees (60 degrees from the celestial pole)   25 seconds
60 degrees (30 degrees from the celestial pole)   50 seconds


Offline didispeed

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Re: stars
« Reply #3 on: May 28, 2009, 10:33:11 AM »
I thought it would be the other way, long exposure on the northern star and short exposure further away,
because star trails are bigger as you go further away from the northern star
greets
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Offline zamri

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Re: stars
« Reply #4 on: May 29, 2009, 05:03:35 AM »
0 degrees at zenith ( looking above ) exposure time is shorter.

You can try to shoot 1 min exposure using ur zoom lens. 1st shot, 0 degree above head and 2nd shot 60 degree ( 30 degree from celestial point ). You will definitely see the different length of star trails. This is because of the earth rotation.

Yap that if you pointed ur camera at Northern Star, what i refering is away from the northern star as you know that the movement of the sky from our naked eye is from east to west because of the earth rotation. In actual facts the stars didn't move.

Further can refer to this Celestial Coordinate System:http://www.astromax.org/faq/p-align.htm