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Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

astroanarchy.blogspot.com

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Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#81

Post by aylmao »

jakobdabo wrote: post #79

On a camera in manual mode if you increase the exposure time, you must compensate the increased amount of light coming to the sensor by decreasing the aperture or the ISO. Can anybody please explain, how is it possible to have such a long exposure without overexposing the image?

By using very low ISOs. You want to use the lowest ISO possible because the lower the ISO the less noise in the picture, and noise in the night sky can be very noticeable since you are photographing a ton of tiny dots against a black background.

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#82

Post by quesera »

wahern wrote: post #74
uhtred wrote: post #70

Earlier quoted context omitted.

Agreed. I very recently was thinking about how humans up to a few hundred years ago must have seen the most breath taking night skies. Imagine a native American standing in a clearing at night 2000 years ago, with zero light pollution, looking at the night sky and just wondering what it is all about.

Even w/ a clear desert sky hundreds of miles from the nearest city (e.g. middle of Nevada), the sky looks nothing like these pictures. Astrophotography uses exposure times many multiples--and usually several orders of magnitude--longer than the human eye. Can you see the Milkyway? No, not really; not without prompting. If you have no idea what to look for, the disc is just a barely imperceptible, slight increase in o…

I agree with your larger premise, but:

> Can you see the Milkyway? No, not really

This is not my experience. I have seen the Milky Way very clearly from a few locations in the US. None are particularly remote -- all are just a few hours drive from the large cities I've lived in. Winter months are clearer than summer.

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#83

Post by Miraste »

jakobdabo wrote: post #79

On a camera in manual mode if you increase the exposure time, you must compensate the increased amount of light coming to the sensor by decreasing the aperture or the ISO. Can anybody please explain, how is it possible to have such a long exposure without overexposing the image?

If you want longer exposures than your lowest ISO can handle you can also use neutral density filters, which go over the lens and reduce the amount of light hitting the sensor.

https://en.wikipedia.org/wiki/Neutral-density_filter

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#84

Post by ksml »

jakobdabo wrote: post #79

On a camera in manual mode if you increase the exposure time, you must compensate the increased amount of light coming to the sensor by decreasing the aperture or the ISO. Can anybody please explain, how is it possible to have such a long exposure without overexposing the image?

Note that these images are made from many exposures that are then processed and combined, and the total exposure time is given. The individual exposure times were probably long, but I'm guessing on the order of minutes, not hours. (Actually, if you photograph stars with an exposure time that is too long, then you get star trails in the image.)

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#85

Post by quesera »

phaedrus wrote: post #60
dding wrote: post #6

Wow amazing work! The scale of this project reminds me of another photographer's five year project of creating a 2.5 gigapixel photo of Orion: https://orion2020v5b.spaceforeverybody.com/

Something about that Orion photo in particular makes it seem beyond belief that there is not other life around other stars in the galaxy.

For me, it was this image and story that removed any shred of doubt:

https://en.wikipedia.org/wiki/Hubble_Deep_Field

The tiny speck of dust that is our whole world is less than a grain of sand on the beaches of the universe.

We are not alone.

Which doesn't mean that we would want to meet any of our neighbors!

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#86

Post by jonplackett »

Holy crap the universe is massive.

It occurred to me the other day that there's barely any science fiction that even occurs outside our own galaxy (Star Wars being the exception that proves the rule). And if it does it's usually something from Andromeda right 'next door'.

Even Star Trek only leaves the galaxy maybe one time, and that requires the help of Q.

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#87

Post by jjnoakes »

quesera wrote: post #82
wahern wrote: post #74

Earlier quoted context omitted.

Even w/ a clear desert sky hundreds of miles from the nearest city (e.g. middle of Nevada), the sky looks nothing like these pictures. Astrophotography uses exposure times many multiples--and usually several orders of magnitude--longer than the human eye. Can you see the Milkyway? No, not really; not without prompting. If you have no idea what to look for, the disc is just a barely imperceptible, slight increase in o…

I agree with your larger premise, but: > Can you see the Milkyway? No, not really This is not my experience. I have seen the Milky Way very clearly from a few locations in the US. None are particularly remote -- all are just a few hours drive from the large cities I've lived in. Winter months are clearer than summer.

Yeah I agree. Not only have I seen the milky way, but I've seen andromeda with my naked eye from the right place on the right night, within a day's drive from very populated cities.

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#88

Post by birktj »

kgran wrote: post #52
dding wrote: post #6

Wow amazing work! The scale of this project reminds me of another photographer's five year project of creating a 2.5 gigapixel photo of Orion: https://orion2020v5b.spaceforeverybody.com/

Looking at these pictures, I've began to ponder how much of an influence the night sky has been in religion and mythology throughout the millennia.

That is exactly the feeling I get the couple of times when I am out hiking hiking and see the most spectacular winter night sky. The feeling of being in the middle of nowhere and seeing the dark sky with an uncountable number of stars is indescribable. I believe it is a great loss of modern society and I really hope we are able to do something about it, we could do just fine without most of the street lighting we have today.

Re: Milky Way, 12 years, 1250 hours of exposures and 125 x 22 degrees of sky

#89

Post by m463 »

jonplackett wrote: post #86

Holy crap the universe is massive. It occurred to me the other day that there's barely any science fiction that even occurs outside our own galaxy (Star Wars being the exception that proves the rule). And if it does it's usually something from Andromeda right 'next door'. Even Star Trek only leaves the galaxy maybe one time, and that requires the help of Q.

Too bad it's so far away.

There's that saying... too young to explore the world, too old to explore the universe.

When our children's children learn to extend their life, or figure out some sort of suspended animation, or pload their brain... what wonders they will see.

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