Astrophotography - Tripods vs Motorized Mounts

a reply to: eriktheawful

If you live in New York, you will see more of the northern sky, and see the spin point of the north part of the axis, but you will not be able to see the southern spin point because you are above the equator.

Yes, but no matter where you are, the sky above is equally divided in two halves, there is no motion that would make stars in one half appear to move faster.

a reply to: IntruderAlert

It's been explained several times now: It looks that way due to the fact the Earth is spherical in shape and rotates, giving the stars an apparent motion.

Because of the shape of the Earth and it's spin, those stars located above the Earth's northern and southern axis will have an apparent motion slower than those located towards the equator.

If you live in the northern hemisphere, due to the curve of the Earth, you will not be able to see the southern point, and vice versa for those living in the southern hemisphere. You can only do that if you live on or near the equator.

I've even told you how to simulate it with a camera.

Now, you're off topic. The topic of the thread is about Astrophotography, not Earth's motion, shape or rotation. If you'd like to discuss that: make a thread about it.

a reply to: TarzanBeta

Yes & No I have a Sony SLT so mirror is fixed many cameras have mirror lock up or you use self timer for a couple of seconds delay before shutter opens.

Been awhile since i posted in here, so I apologize if I post pictures wrong or anything like that.

I've always been fascinated with Astrophotography, it's beautiful!

In 2015 I was travelling in Australia/NZ and did my first 'proper' photos...

How do I go about putting some pics in here?

Those pictures are awesome, and I love to see more threads about astrophotography here, or Astro filming if that's even possible.

I'll hope I've got the time someday to buy and do this one day.
I've seen that there are apps in the app store to use your phone that you use to do time-lapse videos, I don't know if those work but I've got the feeling you guys can tell me that?

As I searched for those time lapse apps, I wondered if the internal GPS can be used to track the earth rotation on a steady point then you only need a tripod the program can do the rest?

a reply to: makkerskilap

If you have your pictures uploaded to a place like tumbler, imageshak or photobucket, your can just post a direct link to the image. We won't see the image but we can click on the link.

If you want to embed your pictures in a post, you'll need to upload it to ATS. Here's a thread on how to do that. It's about making your own avatar, but you do the same thing for uploading:

www.abovetopsecret.com...

a reply to: eriktheawful

Now, you're off topic. The topic of the thread is about Astrophotography, not Earth's motion, shape or rotation. If you'd like to discuss that: make a thread about it.

I was discussing a claim you made in this thread. I am not satisfied but I'll leave it at that to avoid the trolling accusations that will follow. I am honestly just trying to make sense of things that really don't.


So can you answer a question that would be more on topic.


Let's say you are completely zoomed in to Polaris with your camera, or a telescope, how long can you keep it in the image without having to use that device to change the angle.

a reply to: IntruderAlert

Depends on the focal length of the lens (or telescope) you are using. The longer the focal length, the more "zoomed in" you are.

Polaris, while called the North Star, is located at RA 2h 31m 49s, Dec +89° 15′ 51″. Because it's declination is not at a perfect 90 degrees, there will be errors in tracking.

But 89 degrees and 15 minutes is damn close to true 90, so for wide angle lens, it will not appear to move, however the more "zoomed in" you go, the more it will appear to do it's own little arc of rotation.

This is why when anyone does long term exposures using a tracking mount, if they are using a long focal length (say a 200mm or 500mm telephoto lens) and are shooting a object (like M42, Orion Nebula), you'll most likely have to use a tracking scope or a tracking CCD camera to stay on it during any long term exposure (many minutes). You'll most certainly have to do it when taking images through a large telescope (focal lengths of 1400mm or more).

a reply to: eriktheawful

Ok, so let's say you have a large telescope zoomed in at Polaris.

What would happen if you keep the exact same orientation(in space) but place the whole telescope, let's say, a 100m to the East, or West, would it still be zoomed in on Polaris?

a reply to: eriktheawful

Thank you. I actually figured it out while eating my dinner just now, lol.
Can't seem to find the pics after I upload them though, so I'll just do this...

imageshack.com...

imageshack.com...

imageshack.com...

a reply to: IntruderAlert

If you move the telescope 100m to the East or West, but you put the RA and Dec coordiantes for Polaris back into it, you will be looking at Polaris again, as long as you align it again.

If you, instead, leave it set to what it was, then pick it up and carry it to 100m in any direction, and plop it back down, you ain't going to see jack, as you've just screwed up it's polar alignment.

If you move the telescope mount, you will have to re-align it's polar alignment in order to use the RA and Dec coordinates to find something in the sky again.

a reply to: makkerskilap

Awesome pictures!



Thanks for sharing with us!

a reply to: eriktheawful

If you, instead, leave it set to what it was, then pick it up and carry it to 100m in any direction, and plop it back down, you ain't going to see jack, as you've just screwed up it's polar alignment.

Bam.

a reply to: IntruderAlert

Bam what?

Did you come into this thread to discuss astrophotography or not?

a reply to: eriktheawful

So you can't move it a mere 100 meter in any direction and keep it alligned without changing the angle.

So what about the 67,000 miles per hour, or 19 miles per second that the Earth is moving around the sun, which you apparently don't have to take into account?

You are only taking into account the movement caused by the rotation of the Earth, and the declination of Polaris, which are relatively small compared to the movement caused by orbiting the sun.

a reply to: eriktheawful

Thank you. I really wanna do more photos like this, but you know, the time's gotta be there.. They are taken in the Australian outback

I actually think I captured a shooting star, what do you guys think? Taken in the Australian outback :-)

These following ones are unproccessed. Not sure how to put them in in a gif or whatever and the uploading isn't working for me atm, but to my amateur eye isn't that a shooting star moving across? You should view them in quick succession. Maybe it's just the earths rotation :-D

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a reply to: IntruderAlert

The Earth's movement around the Sun is so slow compared to the distance it has to travel, with celestial objects being so far away, that one does not need to compensate for it. The movement is so slow in comparison that in order to need to compensate for it would require so many hours that the Earth will have rotated more than once before that need arises.

The reason you need to align the telescope is because you've zoomed in on a object with a huge focal length (sometimes in the thousands of mm) where as the average focal length of a person's eye is just 17mm

Now, do you have ANYTHING to add to the actual topic of the OP? If not, I suggest you go find a thread that is actually about whatever it is you want to talk about, in which you seem to be trying to prove something, and if it's what I suspect, I suggest you go find those threads instead.

Have a nice day.

a reply to: IntruderAlert

WARNING FLAT EARTHER ALERT The stars are so far away the movement you talk about cant bee seen but be a fraction off aligning with the POINT of rotation and you get problems.

Is it that hard to comprehend well unless you think the Earth is flat.

edit on 17-2-2017 by wmd_2008 because: (no reason given)

a reply to: eriktheawful

We are discussing Astrophotography and the techniques needed to allign telescopes, completely on topic.

The Earth's movement around the Sun is so slow compared to the distance it has to travel, with celestial objects being so far away, that one does not need to compensate for it. The movement is so slow in comparison that in order to need to compensate for it would require so many hours that the Earth will have rotated more than once before that need arises.

Nonsense, you said it yourself, moving it a 100 meter IN ANY DIRECTION would throw off allignment.

Orbit around the sun causes the telescope on Earth to move 19 miles per second.

If your excuse is that celestial objects are too far away, then the rotation of the Earth, which is a movement that is at least 67 times slower should not affect your allignment either.

You really don't see the huge contradiction here and the enormous problem.

a reply to: makkerskilap

I call those "wow" shots, because when I look at them I go: WOOOOOW!



Seriously, I'm jealous. I'm stuck up here in the Northern hemisphere, and I've always thought the skies in the Southern hemisphere have so much more interesting things to take pictures of!