newbie here wanna take photo of star.

For people new to astronomy who want to ask those questions that they were afraid to ask. Receive helpful answers here.
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orly_andico
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Post by orly_andico »

"Do things by yourself, it's creepy. Do it with a bunch of guys, it's a club."

Everybody has to deal with the creepy-itis. Best bet is to have a couple observing buddies along...
elnie
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Joined: Sat Jun 18, 2011 2:01 pm

Post by elnie »

Hmmm....I shall look out for any group activities and try to join one of these days.

As you said it, it is creepy. I tried doing it with my dog, but i'm afraid she'd knock over my camera tripod (she did once).
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cloud_cover
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Post by cloud_cover »

Hi Elnie,
Sorry for the late reply.
I don't really have a favourite place in Singapore to take photos but I do live int he northern edge of Singapore so generally my northern skies are darker. Having said that, the pic I posted of the Scorpio-Saggitarius area was taken facing south, towards the CBD.
Doing a shot like that using a DSLR will require the use of stacking (to reduce noise) with Registax or DSS and some processing to remove the noise pollution (google this topic - lots of tutorials basically advising to remove the stars as best you can, median blur, invert then subtract the inverted layer).
Of course if you're in a dark site then no post processing is necessary :)
So your house window can be a fantastic place to shoot the skies safely and comfortably, you just need to process a bit more :)
DON'T PANIC
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fizzy123
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Post by fizzy123 »

Hi Uenuei,

It is great to hear you pick up star gazing as one of your hobbies and that you are cosidering of dabbling into astrophotography. I am also currently trying out some astrophotography but i am restricting my self to only wide angle DSLR, non tracking type of photography as I don't want to spent too much money into it yet. These are some of the lessons that I have learnt for the pass few months, I am not sure if it is useful for you.

To answer all of your questions, put it simply and shortly, you really have to go out there with a basic tripod and a camera that allows for longer exposure; to try it out for yourself. All cameras are designed differently and there is no hard and fast rule.

The Camera of choice is naturally a DSLR as most models will allow for exposures up to a min and even hour for the Bulb mode on the more advanced models. I have also come to notice that the more advanced compact camera models have the ability to do exposures more than 1s, so those compact cameras might be useful for you too.

So what you do next is to secure the camera to the sturdy tripod, turn the focal length of the lens to the lowest e.g. 18mm and aim it at a general sector of the sky, preferably with brighter stars in it. Manual focus the lens by turning it to the inifinity (far distance) focus, it is usually depicted by a mountain icon. Well for this, I am not sure if this is unique to my DSLR only as most astro-books will describe turning the focus all the way to infinity focus side; but from my experience it seems that the ideal focus is actually a little distance from the inifinity focus side(mountain logo). So you might want to snap shot a few trial shots (e.g. at Scorpious at 20sec exposure) to see if the stars are in focus (e.g. pin pricks), adjust it bit by bit towards the macro side to achieve the idea focus. You might then do a little marking on the lens body to remind yourself of the ideal focus.

As for exposure, to be on the safer side of things, try 20 second exposure. With increased in exposure time you can capture fainter stars but you are also capturing light pollution and the star motions thus some trailing might be detected. You might want to try a series of exposure time to determine whats the best timing for an ideal shot of the stars. You might also want to push up your ISO setting to say 400 or 800 and use a higher resolution setting to capture fainter stars, but of course the drawbacks are that the sky will look more pinkish due to light pollution and trailling might be more severe. If you want to deal with the trailing issue without burning your pocket, you might want to use a barn door device, which a simple to construct add on device to a typical tripod to allow for some tracking via manual turning of a simple round headed bolt. There is a thread about this device on the DIY section.
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