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Telescopes – Facts, Myths and Misconceptions

Telescopes – Here we will look at the facts and expel some of the myths and Misconceptions surrounding scopes.

And answer questions such as – What can you see through a scope? Can you see color? Can you see the same things as the Hubble Photographs? There are so many questions and hopefully some of them will be answered here so will know what to expect from that shiny new scope.We will also let you know the facts of Magnification

Myths and Misconceptions

 What will you really see?

What you will see through a telescope is one of the biggest misconceptions people make when they buy their first telescope. They have many preconceived ideas on what they will see. We have all seen the images taken by the Hubble Space Telescope and you will even find these images on the box the telescope comes in, so is it little wonder that some people will believe that this is what they are going to see when they point their new telescope skywards!

The Hubble has shown us detail and color of our universe that we could never have imagined. The incredible colors in Nebulae, the intricate detail in the Galaxies, Stars dying and being born and all in such wonderful color and detail.

Unfortunately you will not see what the Hubble can see, don’t forget you’re earth bound and have earth’s atmosphere to deal with. When you look directly overhead, you’re peering through about 7 miles of troposphere, this is the densest portion of the earth’s atmosphere. The light from an object nearer to the horizon filters through dozens of miles of this troposphere, the result is blurry Stars. And have you ever wondered why Stars twinkle? It is due to turbulent air which will affect your viewing.

The pictures below are as accurate as I can make them on the internet. Even though they may not be perfect they are a very close representation of what you will see through different telescopes.

Expelling the Misconceptions of Color

Misconceptions – Your normal color vision switches off when viewing very dim light and your semi monochromatic vision takes over. What does that mean? The monochromatic vision is sensitive to the yellow-green part of the color spectrum, but your brain interprets this as shades of gray. On very bright objects, for example the planet Jupiter, you will see pastel colors and dark shading. When viewing some Nebulae,there is a misconception that you will see bright colors, unfortunately you will only see pastel shades of green and some red.

Misconceptions – Think of your eyes like the shutter of a camera except for one major difference, A camera exposure can last for hours giving you the wonderful astronomy pictures you have seen, whereas your eyes have a shutter speed of about 1/20 seconds. Now I’ll show you what all this means, the pictures are courtesy of Adelaide Optical Centre of Australia. They sell most top brand telescopes. If you live down under, have a look at what they offer

Misconceptions – The moon is the closest object you will view from your telescope and will give you awesome views. The picture below shows you what you can see with binoculars 8×42 or 7×50. As you can see the larger craters are just visible.

moon

Misconceptions – This picture below shows what you will see through a typical telescope. Our moon is so bright even a small telescope will get views like this. When viewing a full moon you will find it very bright on your eyes and you may wish to get a moon filter to cut down the brightness.

Misconceptions moon

Misconceptions – Jupiter is the most watched of all the planets among amateur astronomers. You can see the great red spot change hourly and observe its many cloud bands. This picture below shows you what you will see through binoculars 8×41 or 7×50. Jupiter appears as a tiny disk and on the right of the picture are two of Jupiter’s moons.

jupiter moon

Misconceptions – The image below of Jupiter is what you would see through a telescope of 50 to 100mm aperture with about a 100x magnification. You can clearly see two of Jupiter’s cloud bands and all four of its largest moons which show up as white stars. You would see the moon’s orbits after about one hour.

Misconceptions moons orbit

Misconceptions – The picture below shows Jupiter looking through telescopes 200mm or larger apertures on about a 150x to 200x magnification. On a clear night you can see good color and detail plus watch the moons and their shadows crossing the face of Jupiter.

Misconceptions jupiter

Misconceptions – Now lets turn the telescope onto Saturn. This picture shows you what you can see through a telescope of 50 to 6mm aperture on 50x to 100x magnification. The star you can see at the lower right is Titan, Saturn’s largest moon.

Misconceptions largest moon

 Misconceptions – The image below shows Saturn using a telescope 200mm or larger on 200x magnification you can also see up to six moons. NOTE – Saturn’s equatorial belt shows up white in this picture as it was taken after a large storm near the planet’s equator.

planet's equator

Misconceptions – Here is a picture of Omega Centauri the globular cluster (NGC5139). This image is what you would see through 60 to 100mm telescopes.

Misconceptions 100mm telescope.gif

Misconceptions – Now the same view of NGC5139 from a 200mm telescope which shows the outer region more resolved.

Misconceptions 200mm telescope.gif

Misconceptions – This is the Spiral Galaxy M83 seen through a 100mm telescope at 200x magnification. You can only see the bright nucleus and just a small hint of the spiral arms

Misconceptions  Spiral Galaxy

Misconceptions – Now look at the Spiral Galaxy using a 250mm or larger telescope. You can clearly see the spirals detail.

Misconceptions

Misconceptions – There are so many beautiful objects in the night sky to view, but this will depend on many factors – the most important being your telescopes aperture. Other important factors are seeing conditions and where you view from – city or rural, and of course the brightness of the object. What you will see will depend on your level of experience in finding objects through your telescope, of course it will take time to learn. The good news is, there are many ways to get the knowledge you need.

Misconceptions – Learning about the night sky is important but the good news is, it’s a lot of fun with the excellent, inexpensive software programs you can buy. The software I use is the one I can recommend, called Starry Night. There are three versions to choose from called Starry Night Backyard, Pro, and Deep Space all are a lot of fun to use and a great way to learn. Starry Night is compatible with Meade Auto Star Telescopes.

Misconception – You may wish to subscribe to an Astronomy Magazine there are several very good magazines to choose from Astronomy Magazine, Discover Magazine, and Popular Science Magazine. All are excellent magazines, my favorite is the astronomy Magazine which has a lot of great information.

Magnification as a matter of FACT…

Magnification – I have seen on more than one occasion a person over-emphasizing a telescope’s “mag”. The main offenders seem to be inexperienced sales people who have never used a telescope or worse someone whose only interest is parting you from your money.

The truth is a telescope’s Magnification is the least important consideration for viewing objects. Yes it will make objects look bigger but there are a lot of pitfalls as well, let me explain…

  •  It will show all the imperfections in the telescope’s optics.
  •  It will cause you to notice the imperfections of your mount with shaking, and even a small breeze will be very noticeable.
  •  A object you are viewing will zoom across your eyepiece and cause you to keep adjusting, to keep up with it.
  •  The telescope will shake when you touch it and even your heart beat will be noticeable.
  •  The instabilities of the earths atmosphere will be very noticeable.
  •  Some objects will appear fussy.

Even experienced observers find it difficult to track an object at very high magnification. The earths atmosphere is rarely stable enough to permit useful magnification beyond 250x, especially if you are observing from suburbia.

Avoid telescope’s that boasts about magnification. Look for terms such as “coated optics” and “diffraction limited”.

This brings us to another important point – Don’t spend money on expensive eyepieces to magnify. Wait until you have the experience to know what your telescope will handle. Instead buy a Barlow Lens which will give your eyepieces more variety with magnification.

Facts about – Sun filters and Your Eyes

Sun Filters – This would have to be the most important subject we will discus on this page. So please after you have read this, I want you to think seriously about what I’m saying here. Your telescope will come with many accessories but the accessory you must avoid is the “Sun Filter” and here is why. The Filter is designed to screw onto your eyepiece so you can view the Sun directly.

Sun Filters – are Extremely Dangerous to Use and one of the reasons why, is that your telescope collects light and heat which causes enormous thermal stresses in an eyepiece. Your eyeball contains no pain nerves, this means when your eyes are burning, which will take only split second you will not feel it until it’s too late.

Sun Glass

A 100mm telescope can burn aluminum so if the Sun filter cracks while you’re viewing you won’t stand a chance against permanent eye damage or blinding.

One heartbreaking case I read in the newspaper was about a six year old boy who was watching his father viewing the sun with his telescope. When the father was finished, he packed up his accessories and took them into the house, but by the time he had come back for the telescope it was already too late.

The boy had viewed the sun without the filter. He was rushed to the hospital but there was nothing that could be done for him. He had burnt both eyes and was blinded for life. It had only took a split second to change this little boy’s life for ever. I know that this story has nothing to do with a faulty Sun filter, but you can see how easy it can be for an accident to happen, especially with children around.

There have been many reports of people being blinded due to Sun Filters and until they are banned all over the world there will be many more. Australia, so far, is the only country that has banned Sun Filters from sale. I read a review at cloudy nights by an amateur astronomy.

I was appalled to read his suggestion on how to make your own Sun Filter. It is negligent to one – suggest this to anyone and two – to post this on the internet for all to see. Please, Please, NEVER make your own Sun Filter the risks are too high.

There is only one safe way to view the sun.

  • You can project the Suns image onto white paper. Never look through your telescope or viewfinder to align. Also to reduce the thermal stress on your telescope by reducing the aperture – placing a cover over your telescope with a small hole.

I would advise you view the sun by looking at the satellite pictures you can find on the internet and leave viewing the sun to the experts.

 Facts about Southern Hemisphere and

Computerized Telescopes

For all of you living in the southern hemisphere there will be a few problems you will face when buying a telescope. In the S/Hemisphere the sky spins clockwise, while in the N/Hemisphere it spins anticlockwise. If you buy a computerized telescope or a simple tracking motor you need to be aware of this.

Another problem with cheaper equatorial telescopes is that the supplied RA setting circle index scale (from 0h to “24h”) is usually “backwards” for S/Hemisphere users. You can make your own index by attaching a strip of paper, with the correct labels, over the existing index. As shown below.

Here is the schematic views on the RA setting circle.

In this diagram you are looking down the polar axis.

southern hemisphere

Remember when the telescopes manual tells you to align your telescope, it will probably be using the northern hemisphere stars, so don’t spend the night trying to find stars that are not there.

The better equatorial will have both index scales for the S/Hemisphere and N/Hemisphere, and instructions on which index to use. Ask your local dealer when buying a computerized telescope whether it is set up for the southern hemisphere.

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