Does the star move?

[thenikonguy]

Actually, it's common knowledge among experienced photographers.

yes, but thats not what we're talking about.. it doesnt take an experienced photographer to know that the earth rotates...

When I made a comment about the OP not knowing this, you stated that I made a similar stupid remark in 1 of my posts, however, not know the purpose of a circular polarizer spinning, and not know that the earth rotates are 2 DRASTICALLY different things... I believe we learned that the earth rotates in grade 1 or 2 science..

 

[avilamillar]

Sorry for my ignorance hehe, i DO know that the earth rotates but i thought that effect of the stars only happened with very long exposures. both were ISO 100 f/9 first 5 minutes and second 8 minutes.

And i have one more question, i went camping 2 weeks ago and the sky was beautiful, i have never seen that much of stars, but i didnt have my remote so i could leave the shutter open only for 30 seconds:

How do you do to take pictures of the stars like this: Star Field Exposure Time: 25 seconds ( Death Valley, California, USA )

im impressed of how many replies i had in this post because for some people this is funny and when i tried to get some C&C of my pictures or ask some for help choosing the accessories for my camera no one answered.

Thanks for the help

 

[robertwsimpson]

to freeze them, you'd need really bright stars, no moon, high ISO, decently wide aperture, and a short exposure, and a complete absence of ambient light. That way, you won't completely blow out everything else in the picture trying to get a picture of the stars.

 

[Village Idiot]

Watch a shadow once. You'll be able to discern the rotation of the Earth and how fast it moves by doing so. Mark a point on a wall or something. Give it 5 minutes, and mark it again.

 

[avilamillar]

Thanks again, that day there were REALLY bright stars, we were camping so it was a complete absence of ambient light.

this is another with ISO 800:

 

[robertwsimpson]

looks pretty good to me!

also, if you don't want to get trails and you're not worried about getting foreground in the picture, you can get a tripod that follows the sky as the earth rotates. check it out.

 

[avilamillar]

thats ok thanks

 

[henryp]

in this pictures the stars seem to be like they moved! why did this happen?

Go to Google images and use 'star trails' as your search term. Remarkable stuff including some excellent 4+hour exposures from NASA.

 

[Samanax]

More than 1/2 of the people in a recent survey did not know that the Earth revolves around the Sun.

Nor could they explain exactly what a year is.

Wow, that's sad. The idea in the movie Idiocracy (that man is getting dumber) seems to be coming true.

Some time ago I was shocked when I overheard a high school senior arguing with a few others saying that Hawaii was the 51st state in the union, not the 50th. And he was a private school senior, not public school which made it even more disturbing. He honestly thought there were 51 states in the union...and we live in Hawaii.

 

[beala]

This reminds me of those infamous interviews with Harvard graduates. When asked, a majority of newly graduated Harvard students didn't know what caused the seasons.

MiddleSchoolPortal/The Reasons for the Seasons - NSDLWiki
"Interviews with Harvard graduates in the late 1980s illustrate how widespread these misconceptions about the seasons are. When asked what causes the seasons, most of the newly graduated students gave the same wrong answer that many people give: the seasons are caused by earth getting closer (or farther) from the sun."

In any case, I'm finding my Astro 101 knowledge indispensable when taking astronomy pictures. With some basic astro knowledge you can pretty easily predict where and when the sun/moon will rise, and how star trails will look in your pictures.

 

[Guido44]

Let's all watch it together. Ready .... GO.

 

[Guido44]

OOOOooooh .... aaahhhhh.

 

[Dwig]

...
in this pictures the stars seem to be like they moved! why did this happen? ..

Stars move, but they move so slowly, from our point of view, that you'll never see it in a photograph. What happened in your pix was that the earth moved, smearing the image of the stars. At the equator, when you stand "still" you're actually moving at almost 1000 mph.

The earth spins approximately 15 degress per hour. A 4 minute exposure will leave a star trail of 1 degree of arc. The stars near the pole will seem to trace a tight arc and those near the equator will trace a larger arc, hence a longer line.

 

[Figment]

Hehe... poor Guy...

And to answer your question, as many have stated, on an 8 minute exposure the earth moves A LOT. Therefore, you're going to get quite a bit of "streaking".
I did a few of these one night, but there was too much light to get them to come out well.
Pretty neat shots though.

 

[Actor]

How many people truely realise the Earth rotates from West to East, let alone that galaxies like Andromeda have their light shifted to the blue end of the spectrum?

It's shifted toward the red. That's why it's called the red shift.