Telescope with 140+km zoom?

[babadoctor]

Does this exist, and is it possible for such a thing to exist? If so, how much would one cost? 

[AkiraDaarkst]

10 minutes ago, babadoctor said:

Does this exist, and is it possible for such a thing to exist? If so, how much would one cost? 

To what magnification?  If I can see the rings of Saturn with my 114mm Newtonian telescope and 100x optics, I'm certain something 14km away is no big deal as long as it was within line of sight.  But don't expect to see something 14km or more away on a horizontal line due to the planet's curvature.  You'd have to be at a minimum specific height above (i.e. sea level) to see such distances on the surface of the planet.

[babadoctor]

1 minute ago, AkiraDaarkst said:

To what magnification?  If I can see the rings of Saturn with my 114mm Newtonian telescope and 100x optics, I'm certain something 14km away is no big deal as long as it was within line of sight.  But don't expect to see something 14km or more away on a horizontal line due to the planet's curvature.  You'd have to be at a minimum specific height above (i.e. sea level) to see such distances on the surface of the planet.

I don't know how magnification works in accordance to distance.

I understand how the earth's curvature will affect what I will see; I intend to aim the hypothetical telescope up to compensate.

[babadoctor]

50 minutes ago, AkiraDaarkst said:

To what magnification?  If I can see the rings of Saturn with my 114mm Newtonian telescope and 100x optics, I'm certain something 14km away is no big deal as long as it was within line of sight.  But don't expect to see something 14km or more away on a horizontal line due to the planet's curvature.  You'd have to be at a minimum specific height above (i.e. sea level) to see such distances on the surface of the planet.

http://www.skyandtelescope.com/observing/celestial-objects-to-watch/skyandtelescope-coms-scope-calculator/

How can I use this to calculate distance?

[keenhydra]

What do you plan on watching? 

 

And basically every telescope can see distances that far, it's just the size of the object you want to see that matters.

 

50x optics can help you look at the moon for example but 100x could show you Jupiter or Saturn as above mentioned. 

 

I'm not a star gazing enthousiast but just guessing here

[babadoctor]

15 minutes ago, keenhydra said:

What do you plan on watching? 

 

And basically every telescope can see distances that far, it's just the size of the object you want to see that matters.

 

50x optics can help you look at the moon for example but 100x could show you Jupiter or Saturn as above mentioned. 

 

I'm not a star gazing enthousiast but just guessing here

Let's say I wanted to aim it at an object on earth that is 240km away, and I have a direct line of sight to the object...

Lets say that object is a red ball 240 kilometers away from my location, and I have a direct line of sight to it.

I kind of understand how light is bent and distorted over long distances... 

 

Do you know what forces I would need to compensate for?

Thanks

Also, how much would a telescope that could reach that distance be?

[keenhydra]

1 minute ago, babadoctor said:

Let's say I wanted to aim it at an object on earth that is 240km away, and I have a direct line of sight to the object...

I understand how light is bent and distorted over long distances... 

 

Do you know what forces I would need to compensate for?

Thanks

Also, how much would a telescope that could reach that distance be?

For a distance of that little light barely bends so I wouldn't worry about that. Only thing I would do some research in is the amount of ambient light you have and how much your telescope will capture.

 

If I'm correct shorter telescopes catch more ambient light than longer ones so if you're watching a satellite or whatever that doesn't emit or reflect a lot of light you may need a longer telescope to look at it with starlight and moonlight around it. Don't quote me on this, this is just educated guessing

 

And judging on prices in the EU I'd suppose you need around $200 to $300 for a decent model, then again Im not qualified to judge if a model is decent

[TVwazhere]

1 hour ago, AkiraDaarkst said:

But don't expect to see something 14km or more away on a horizontal line due to the planet's curvature.  You'd have to be at a minimum specific height above (i.e. sea level) to see such distances on the surface of the planet.

Inb4 "Earth is flat"

[babadoctor]

19 minutes ago, keenhydra said:

For a distance of that little light barely bends so I wouldn't worry about that. Only thing I would do some research in is the amount of ambient light you have and how much your telescope will capture.

 

If I'm correct shorter telescopes catch more ambient light than longer ones so if you're watching a satellite or whatever that doesn't emit or reflect a lot of light you may need a longer telescope to look at it with starlight and moonlight around it. Don't quote me on this, this is just educated guessing

 

And judging on prices in the EU I'd suppose you need around $200 to $300 for a decent model, then again Im not qualified to judge if a model is decent

Okay

Could you possibly link a telescope that you recommend? 

[keenhydra]

9 minutes ago, babadoctor said:

Okay

Could you possibly link a telescope that you recommend? 

ehhmm no, I'm just judging from general pricing here. i have no knowledge about telescopes or their parts.

 

for all i could recomend just going on amazon or anything similar and looking for yourself, does the product look good, how much does it cost, what are the reviews.

 

I literally have no idea what a good telescope costs..

[Thunderpup]

While i have very little knowledge on Telescopes i do know that magnification isn't a very important factor.

 

Here is an article written by Astronomer Phil Plait who provides a FAQ of sorts for shopping for telescopes.  
http://www.slate.com/blogs/bad_astronomy/2014/12/01/telescopes_how_do_i_buy_a_telescope.html

 

Below is an updated christmas buying guide written by the same dude for last year.  Some of it is a rehash of his FAQ but he does point out some good starter telescopes. 
http://www.slate.com/blogs/bad_astronomy/2015/12/16/telescope_buying_faq_for_2015.html

 

 

I hope some of this helps. 

[PCBjon]

http://www.cloudynights.com/index is the place for all your telescope questions 

[dalekphalm]

2 hours ago, babadoctor said:

Let's say I wanted to aim it at an object on earth that is 240km away, and I have a direct line of sight to the object...

Lets say that object is a red ball 240 kilometers away from my location, and I have a direct line of sight to it.

I kind of understand how light is bent and distorted over long distances... 

 

Do you know what forces I would need to compensate for?

Thanks

Also, how much would a telescope that could reach that distance be?

240 km is roughly 150 miles.

 

At that distance, the curve of the Earth will get in your way, if you intend on looking at an object on the ground:

http://www.davidsenesac.com/Information/line_of_sight.html

 

So at 148 miles away, you (or the object) must be 14,496 FEET high to see it over the horizon. That's 4.4 km, for reference.

 

So if you're sitting at home, and you want to look at a baseball that is 240 km away, that baseball needs to be on top of a 4.4 km tall mountain.

 

EDIT: Light is not distorted over that kind of distance. Light is distorted by gravity, not by distance. And the amount of gravity needed to distort light is massive.

[babadoctor]

18 minutes ago, dalekphalm said:

240 km is roughly 150 miles.

 

At that distance, the curve of the Earth will get in your way, if you intend on looking at an object on the ground:

http://www.davidsenesac.com/Information/line_of_sight.html

 

So at 148 miles away, you (or the object) must be 14,496 FEET high to see it over the horizon. That's 4.4 km, for reference.

 

So if you're sitting at home, and you want to look at a baseball that is 240 km away, that baseball needs to be on top of a 4.4 km tall mountain.

 

EDIT: Light is not distorted over that kind of distance. Light is distorted by gravity, not by distance. And the amount of gravity needed to distort light is massive.

Okay, let me rephrase that

85 miles exactly, not 240km (sorry, i miscalculated)

so, around 140km

[dalekphalm]

3 minutes ago, babadoctor said:

Okay, let me rephrase that

85 miles exactly, not 240km (sorry, i miscalculated)

so, around 140km

The same principle applies:

At 87 miles away, the object must be 5,000 feet high to see over the horizon. That's a little over 1.5 KM high. So if we use 85 miles instead of 87 miles, we can just round straight to 1.5 KM high and call it even.

 

If you're looking at a mountain in the distance? That's totally fine, assuming it's a high enough peak. Office buildings or other man-made objects? Not going to happen. The tallest buildings in the world still fall short of even 1 KM high, so even if you went to Dubai and went to the top floor of the Burj Khalifa - the tallest building in the world at 2700 ft or 826m tall - you're still not going to be able to see line-of-sight for an object 85 miles away.

 

If you're in a helicopter, airplane, or blimp, etc, you could in theory look at something 85 miles away, if you got high enough. The problem is that you'd likely be way too unstable to get a clear view, without a high-end optical mount on a Gimbal that compensates for the movement of the vehicle.

 

If you're looking at celestial objects or anything in the sky? Sure, no problem.

 

What exactly are you trying to look at, that's 85 miles away?

[keenhydra]

2 minutes ago, dalekphalm said:

The same principle applies:

At 87 miles away, the object must be 5,000 feet high to see over the horizon. That's a little over 1.5 KM high. So if we use 85 miles instead of 87 miles, we can just round straight to 1.5 KM high and call it even.

 

If you're looking at a mountain in the distance? That's totally fine, assuming it's a high enough peak. Office buildings or other man-made objects? Not going to happen. The tallest buildings in the world still fall short of even 1 KM high, so even if you went to Dubai and went to the top floor of the Burj Khalifa - the tallest building in the world at 2700 ft or 826m tall - you're still not going to be able to see line-of-sight for an object 85 miles away.

 

If you're in a helicopter, airplane, or blimp, etc, you could in theory look at something 85 miles away, if you got high enough. The problem is that you'd likely be way too unstable to get a clear view, without a high-end optical mount on a Gimbal that compensates for the movement of the vehicle.

 

If you're looking at celestial objects or anything in the sky? Sure, no problem.

 

What exactly are you trying to look at, that's 85 miles away?

Damn son.. way to crack down on someone with a question

[dalekphalm]

11 minutes ago, keenhydra said:

Damn son.. way to crack down on someone with a question

Well, he's asking a question that has no correct answer.

 

His question boiled down to "what kind of telescope will let me see an object 85 miles away?" The answer is: "None, because the Earth will literally be in the way".

 

That's why I'm trying to get the OP to clarify his statements and add more information so we can properly help him. Knowing what he's trying to look at will significantly help us in determining what kind of Magnification will help him see what he's trying to look at.

 

But if he's trying to look at, say, a building 85 miles away, unless he's at the top of a mountain (or the building is), he simply won't be able to.

 

At a distance of 85 miles, it's not going to be a celestial object. The lowest LEO (Low Earth Orbit) satellites are approximately 99 miles up - not that you'd be able to see it, since at that distance, the satellite is moving 7.8 KM per second and would fly past too quickly.

 

So by the powers of deduction, the OP is trying to see a land-based object at that distance. Knowing more information is crucial to help him.

[babadoctor]

3 hours ago, dalekphalm said:

Well, he's asking a question that has no correct answer.

 

His question boiled down to "what kind of telescope will let me see an object 85 miles away?" The answer is: "None, because the Earth will literally be in the way".

 

That's why I'm trying to get the OP to clarify his statements and add more information so we can properly help him. Knowing what he's trying to look at will significantly help us in determining what kind of Magnification will help him see what he's trying to look at.

 

But if he's trying to look at, say, a building 85 miles away, unless he's at the top of a mountain (or the building is), he simply won't be able to.

 

At a distance of 85 miles, it's not going to be a celestial object. The lowest LEO (Low Earth Orbit) satellites are approximately 99 miles up - not that you'd be able to see it, since at that distance, the satellite is moving 7.8 KM per second and would fly past too quickly.

 

So by the powers of deduction, the OP is trying to see a land-based object at that distance. Knowing more information is crucial to help him.

Okay, let me add some information; I apologize for being vague

 

Let's say the object that I am looking at (for example, the hollywood sign) is 0.5km above sea level. 

 

I am 85 miles away

 

I want to get a clear view (that can fill up my entire telescope lense) of for example hollywood sign with my telescope (Yes, I know the hollywood sign may not be physically and geographically visible but let's just have a hypothetical here, alright?)

 

According to your calculations, I would need to be at least -1.5km below sea level to see "the hollywood sign" or I would need to be 1.5km higher up than "the hollywood sign" to see it without the earth being in the way. (so, 2.5km above sea level)

Am I understanding your answer so far correctly?

 

Now, let's say that I want to read a piece of paper that is on the hollywood sign, at the same distance, sea level, etc.

Would this work?

What type of telescope would I need?

 

Is there any more information you need? If you need more information to make a more accurate conclusion, please let me know

Thank you

[dalekphalm]

6 minutes ago, babadoctor said:

Okay, let me add some information; I apologize for being vague

 

Let's say the object that I am looking at (for example, the hollywood sign) is 0.5km above sea level. 

 

I am 85 miles away

 

I want to get a clear view (that can fill up my entire telescope lense) of for example hollywood sign with my telescope (Yes, I know the hollywood sign may not be physically and geographically visible but let's just have a hypothetical here, alright?)

 

According to your calculations, I would need to be at least -1.5km below sea level to see "the hollywood sign" or I would need to be 1.5km higher up than "the hollywood sign" to see it without the earth being in the way. (so, 2.5km above sea level)

Am I understanding your answer so far correctly?

 

Now, let's say that I want to read a piece of paper that is on the hollywood sign, at the same distance, sea level, etc.

Would this work?

What type of telescope would I need?

 

Is there any more information you need? If you need more information to make a more accurate conclusion, please let me know

Thank you

Okay so you want to see the Hollywood sign. If it's 0.5km above sea level, and there are no obstructions in the way (Eg: terrain that goes above 0.5km sea level), then you would only need to be 1km above sea level to see it, because the added height on both ends will help to combat the curve of the Earth.

 

So basically, you want to be able to read a piece of paper 85 miles away? There's a lot of math involved in calculating the magnification factor of a telescope, and I cannot find any definitive "calculator" that will give you a meaningful result.

 

I did find this site, which calculates the angular size of an object based on distance and size of object:

http://www.1728.org/angsize.htm

Distance: 85 miles (136 km)

Size: 11 inches (0.0002794 km)

Angular Size:   1.1771e-4 Degrees, which equals: 0.00011771 degrees of "relative: size.

 

To put that into perspective, the Moon, viewed from Earth, is 0.5 degrees. To get a relative size (The paper looking the same size as the moon, you'd need to have a magnification of what... like 4200x? (4248x, by my calculation)

 

And that's still not legible. I cannot find any Degree measurements of a piece of paper (Assuming standard Letter Size, 8.5" x 11") held at arms length. I'd guess 10 degrees or more.

 

Assuming my calculations are correct, to magnify a piece of paper to 10 Degrees of relative size, it would take a magnification factor of approximately 85000x (84954.5x, specifically).

 

Of course, I could be wrong, but from these numbers, I don't think you're gonna be able to read a piece of paper using an "off the shelf" consumer Telescope.

[babadoctor]

1 hour ago, dalekphalm said:

Okay so you want to see the Hollywood sign. If it's 0.5km above sea level, and there are no obstructions in the way (Eg: terrain that goes above 0.5km sea level), then you would only need to be 1km above sea level to see it, because the added height on both ends will help to combat the curve of the Earth.

 

So basically, you want to be able to read a piece of paper 85 miles away? There's a lot of math involved in calculating the magnification factor of a telescope, and I cannot find any definitive "calculator" that will give you a meaningful result.

 

I did find this site, which calculates the angular size of an object based on distance and size of object:

http://www.1728.org/angsize.htm

Distance: 85 miles (136 km)

Size: 11 inches (0.0002794 km)

Angular Size:   1.1771e-4 Degrees, which equals: 0.00011771 degrees of "relative: size.

 

To put that into perspective, the Moon, viewed from Earth, is 0.5 degrees. To get a relative size (The paper looking the same size as the moon, you'd need to have a magnification of what... like 4200x? (4248x, by my calculation)

 

And that's still not legible. I cannot find any Degree measurements of a piece of paper (Assuming standard Letter Size, 8.5" x 11") held at arms length. I'd guess 10 degrees or more.

 

Assuming my calculations are correct, to magnify a piece of paper to 10 Degrees of relative size, it would take a magnification factor of approximately 85000x (84954.5x, specifically).

 

Of course, I could be wrong, but from these numbers, I don't think you're gonna be able to read a piece of paper using an "off the shelf" consumer Telescope.

Holy cow man, thats a very, VERY large magnification number... understandably

 

Can you post the mathematical formulas you used to calculate these numbers?

e.g you used the size of the 8.5x11 paper in your calculations...

 

Let's say that the paper was instead my friends house which is 100 feet long

Where would I plug in the measurements for the building into your formula to find the magnification factor? (100 feet long and wide) the distance (85 miles worst case scenario, 75 miles best case scenario,) the height (0.5 km, etc) and all the other factors I would need to calculate...

 

Just to see my friends house in full view of the telescope;

For example, he calls me on the phone and goes outside and waves his arm, would I be able to see that?

 

Thank you

[babadoctor]

2 hours ago, dalekphalm said:

snip

I got this many degrees for my object

  0.010241 Degrees 

How can I calculate the zoom factor for that? You said "according to my calculations"

What exactly are those calculations?

 

Thank you again

[dalekphalm]

42 minutes ago, babadoctor said:

I got this many degrees for my object

  0.012841 Degrees 

How can I calculate the zoom factor for that? You said "according to my calculations"

What exactly are those calculations?

 

Thank you again

I don't have the specific formulas on hand, but all of the calculations are available via the links I posted above.

 

In terms of taking the Degrees and turning it into a useful number, there are several things we can do.

 

First, this website will calculate the relative size of an object in degrees:

http://www.1728.org/angsize.htm

 

At 25 inches, a 11 inch piece of paper (We'll use the larger dimension, since this assumes a circular object) has a relative size of just over 24 Degrees.

 

Replace 25 inches with the length of your arm. Apparently the average is 25 inches.

 

Anyway so, once you have that figure, you divide the angular degrees of the piece of paper at arm's length, by the angular degrees of the object you wish to magnify at the distance intended.

 

24 Degrees / 0.012841 Degrees = 1868x magnification needed to make them "appear" the same size

 

[keenhydra]

This it getting maths.. I'm out 

[babadoctor]

7 minutes ago, keenhydra said:

This it getting maths.. I'm out 

I love math!

[babadoctor]

2 hours ago, dalekphalm said:

I don't have the specific formulas on hand, but all of the calculations are available via the links I posted above.

 

In terms of taking the Degrees and turning it into a useful number, there are several things we can do.

 

First, this website will calculate the relative size of an object in degrees:

http://www.1728.org/angsize.htm

 

At 25 inches, a 11 inch piece of paper (We'll use the larger dimension, since this assumes a circular object) has a relative size of just over 24 Degrees.

 

Replace 25 inches with the length of your arm. Apparently the average is 25 inches.

 

Anyway so, once you have that figure, you divide the angular degrees of the piece of paper at arm's length, by the angular degrees of the object you wish to magnify at the distance intended.

 

24 Degrees / 0.012841 Degrees = 1868x magnification needed to make them "appear" the same size

 

Let me just put some comparisons up if you don't mind:

Not sure if this is fake or not, but I am guessing it is accurate.

 

One last question; Did you put in 11 inches & 25 inces into that calculator? wouldn't you need to find out how much of a km 11 inches is? I thought it used KM as the base measurement... 

Anyways, why are we using the length of an arm again?

Sorry if that was a stupid question  

 

Thank you so much for helping me through this