All About Telescopes and Binoculars

space the fascinating frontier planets stars nebulas galaxies and they're all yours as you explore all about telescopes and binoculars hi I'm Bob monitor director of the Minneapolis planetarium and an amateur astronomer just like you well maybe not just like you everyone's different we have different interests different types of telescopes and different things we like to look at in the night sky speaking of the sky the universe is a fascinating place however the world of telescopes and binoculars can be somewhat confusing there are different accessories mounts filters and different telescope jargon that you have to pick up on it can be a confusing place but this is what this show is all about to learn more about telescopes and binoculars so you can enjoy the night sky right now we're in the planetarium which is a wonderful place to learn about the night sky but let's head down to the classroom where we can find out more about telescopes and binoculars up close remember to visit your local planetarium here at the minneapolis planetarium we always show a nice clear sky it's never cloudy come on let's get going all right we're down in the classroom here now and we have our telescopes and binoculars and we're ready to show you them but before we get started remember what binoculars and telescopes do they gather and they focus and they magnified light our eyes work much the same way in fact for thousands of years that's all humans had where our eyes until 1610 when Galileo turned the first telescope toward the sky and today of course we have that fantastic Hubble Space Telescope and of course there's a slight difference between Galileo scope and Hubble but remember the basics what telescopes and binoculars do they gather focus and magnified light so what exactly is light well essentially light is energy radiant energy we think of visible light as light from stars or the Sun or maybe even lightbulbs that you see but visible light is a tiny part of the electromagnetic spectrum we have the radio an infrared waves down at the low part of the spectrum and we have the ultraviolet x-rays and gamma-rays at the high part of the spectrum so the visible light we see is just a tiny part of the light or energy coming from space most people usually think of telescopes as collecting only visible light however there are telescopes that collect radio light or radio energy like the Arecibo telescope in Puerto Rico and the Very Large Array in New Mexico however we're gonna focus excuse the pun on the visible light when we look in the night sky we see two kinds of light direct light and reflected light direct light is light radiated from stars or a collection of stars like galaxies reflected light is light that comes from planets or the moon remember when you look in the night sky stars and planets are very different things about four hundred years ago someone got the bright idea to put two lenses inside a tube this new device could see more than the human eye ever could this new device could see more brightly and more detail and add a greater distance this new device of course was the telescope and the first person to turn it toward the sky was Galileo now Galileo didn't invent the telescope and he really didn't know who did Galileo put a convex or objective lens at the front of the telescope and a concave lens at the back of the telescope a convex lens is a polished piece of glass that is thicker at the center than at the edges what this does is bend or refract light so when light passes through the lens the Rays converge and meet at a focal point we see the bending and refraction of light all the time for example take this pencil and stick it in a glass of water and you'll see that the pencil is bent where the air meets the water because the light is being slowed down by the thicker water and therefore it appears bent or refracted a concave lenss is just the opposite of a convex lenss it's thinner at the center kind of like my mattress back home when light passes through a concave lens the light rays spread out or diverge put a convex lens in front of a concave lens and you got yourself a refracting telescope by adjusting the distance between the convex and the concave lens you can provide the focus to your telescope we talked with Loren Nelson an accomplished Astro photographer who graciously provided many of the photographs that you're going to see in this show let's listen to what Loren has to say about his first telescope experience well a very first experience I had was with some lenses my brother had and they were just long focus thin eyeglass type lenses and I put a few of them together like the gal Leo type you know was a negative lens and a positive lens in front and carved a notch in the fence and slipped the lens in there and laid on the ground with the negative lens and looked at craters on the moon and that was my first telescope experience now in the early days of telescopes refracting telescopes were the only ones around but they had some problems one was if the astronomers of the early days wanted to get a bigger image they needed a bigger lens and this caused problems because you need a bigger support tube and bigger support system to hold up the lens another problem with refracting telescopes was a thing called chromatic aberration when light passes through the lens it bends and it can split up into its component colors the spectrum you've all seen rainbows before when this happens you get a ring of color around your image which was not good for astronomers these problems led to a new type of telescope a telescope using mirrors the reflecting telescope now these reflecting or mirrored telescopes in the beginning weren't that great the observer had to look down the tube at the image this of course blocked the image that there trying to see so these stick your head in the telescopes weren't that great enter Sir Isaac Newton the guy who discovered the laws of gravity the spectrum in calculus boy what a genius what Isaac Newton did was stuck a secondary mirror inside the tube that reflected the light out the side of the tube what an ingenious invention these telescopes are still used today on many of the greatest telescopes in the world before we take a look at the different telescope and binocular designs in a moment let's talk about some of the basic concerns with our eyes when viewing the heavens through optically aided telescopes first is of course never look at the Sun without a special solar filter next one you may not be aware of don't look at the full moon for extended periods of time without a neutral density filter now before you can become an expert telescope observer there's one thing you've got to know and that's the night sky spend a few nights and explore the constellations find out where the bright planets are for example know where the constellation Orion is the Orion Nebula so you can find it with the telescope or a pair of binoculars this is a key step many telescope observers often overlook now that you're an expert stargazer the next thing you got to do is read the telescope manual this is very important and it often takes that dreaded P word patience but please read it through look at the diagrams look at the charts this will help you greatly when you turn to your telescope and operate it under the beautiful night sky now all telescopes and binoculars of course have lenses or mirrors an important thing to remember with these lenses is beware the dreaded thumbprint of course do not put any finger prints or thumbs on the lenses you don't want to touch them because these mirrors or lenses are specially coated to enhance the instruments performance and our body oils will cause these coatings to break down resulting in poor performance from the instrument what to do is keep the lenses or mirrors covered when you're not using your instrument even the finest dust particles can scratch the surfaces and accidents can happen I guess that's why they're called accidents if your telescope or binoculars are protected you've got less of a chance of damaging some critical elements should something happen when cleaning your lenses or mirror on your telescope or binoculars what you first need to do is pick up an optics cleaning kit from a local Photo Store once you got that take the can of compressed air and gently blow on the lenses or mirror next take a few of the recommended liquid and add a few drops on each of the lenses and then take the specially designed cloth and wrap it around your index finger and make tight little circles when cleaning the lens or mirror this will clean your lenses the best they can be so you can see the universe finally after you enjoyed a night under the stars make sure that you store your telescope or binoculars properly always put the lens cap back on or a cloth over your mirror on your telescope and properly store it whether your system costs two hundred or two thousand or twenty thousand dollars it's important to properly store your equipment all right we're gonna start our equipment section with binoculars now many things I have to say about binoculars also pertain to telescopes so please pay attention a lot of folks think binoculars aren't very good for viewing the night skies since they're so small and that you have to have a telescope not true binoculars are Wonder foreseen like star clusters the Pleiades the Orion Nebula the Andromeda galaxy you can see star color much better with a pair of binoculars you can even see some moons of Jupiter with binoculars so there's a lot to see if you're only using those binoculars you have for sporting events or music concerts take him out and look at the night sky afterwards I found out that the stars you can see with your naked eye are so much more fun if you can lay in a lounge chair even on the ground with a pair of binoculars and just look up you can see all kinds of things I've seen satellites go through the view of binocular you can start with an inexpensive pair of binoculars for 20 dollars you can look up just lay and look at the Stars and see anything binoculars come in two types the portal prism and the rough prism let's take a look at the Porro prism first this pair of binoculars right here uses the portal prism what happens is the light comes through the objective lens right here and then goes through two sets of prisms one here and one here this folds the light and then shoots it or corrects it to the right way back up through the lens right here the rough prism the two prisms are lined up with each other and the light goes straight through it's more streamlined but the quality is just the same as the Porro prism and pearl prism is cheaper so we recommend the Porro prism system a term you might commonly hear in binoculars and telescopes is eye relief what exactly is that well that's the distance between the lens and what you can see in your binoculars you want to see it all so what you do I mean we kind of do this naturally we go up to a pair of binoculars or telescopes and we look through and we want to see the whole image you don't want any light or anything coming from the offset here so we lit through and a tendency is to put your eyes right next to the binocular or telescope and get as close as you can this is not right you want to find that comfortable distance between the lens and the entire field of view that you want to see so find that right distance you can play a little bit if you want but establish that I relief for yourself so you can see the entire image cool now exactly what are these rubber guards for that we see on a pair of binoculars well they help establish the right eye relief and they also keep out the ambient light however many of us wear eyeglasses and if you do you might want to roll back here the guard if you do that this will allow you to see more of the image when you look at what you're trying to see another key consideration in a pair of binoculars is the aperture or the distance across the objective lens now bigger is not necessarily better the bigger the lens of course the more light you have coming in but as we're gonna find out that's not always the best case now the proper aperture is determined by the exit pupil and we'll be discussing that in just a little bit now many of you have probably noticed that binoculars come with those two pair of numbers for example this pair of binoculars says seven by thirty-five what does that mean exactly well it's not seven times 35 that's 245 and that's math and we're gonna stay away from that seven by thirty-five means well first the seven the seven is how many times the image is magnified by this lens right here magnification is often referred to as the power of the pair of binoculars or the telescope 35 is the distance of the aperture or the objective lens right here and it's measured in millimeters and 35 millimeters equals about an inch and a half now let's do the same thing again but with a bigger pair of binoculars these a 10 by 50 again the 10 the first number is how many times the image is magnified right here by this lens and the 50 is the width of the objective lens or the mature in 50 millimeters equals about two inches when we look through binoculars or a telescope we want all the light exiting the eyepiece to match the width of our eye so how big is your eye or more importantly your pupil well if it's darken conditions your pupil dilates or stretches out to about five to seven millimeters all right how do you figure out the right exit pupil for your binoculars well what you do is you take the aperture say 35 and divide it by the magnification say seven and that equals five millimeters which matches the width of your eye so that's a good pair of binoculars if you do the math on 10 by 50s you also notice that it equals five 50 divided by ten seven by 50 binoculars you do the math you get about seven and that works too so all of these are great pair of binoculars so which is the best one well if you've got the money and you want a little more light coming through the telescope get the ten by 50s or the seven by fifties so why not 2500 binoculars well this is where bigger is not necessarily better there's two issues involved here cost and weight first cost a bigger pair of binoculars will get you up to two three thousand dollars perhaps and if you're gonna spend that much money it might be best to go with a telescope now the weight issue everyone knows that if you use binoculars it's tough to hold them steady so what do you do well treat yourself to a tripod and a binocular adapter for instance let's take these binoculars you'll notice the tripod here here's the binocular adapter and you simply screw in the binoculars here to the adapter and just takes a few seconds and tighten it up real nice and look at that no shaking last but not least we need to focus our binoculars first focus with the main focus right here in the center of the binoculars these will move both lenses at the same time when you got a good image there next second step is to focus using the right-hand knob right here this helps correct for any imbalance between your right and left eye and then you should have a pretty sharp image so that's it for binoculars remember they are small so you might think they aren't so good for the night sky and just take them out for football games and such but binoculars are wonderful for the night sky remember you can see so many things you can see galaxies nebulae you can see planets better all kinds of things so don't forget your binoculars when you do your astronomy I mean too casual observing I don't have the electronic wizardry that other people have I have a rather large telescope it's a 16 inch Meade equatorial mount which I've had for about 12 years now reflector yes thoroughly I just love it all right it's telescope time there are three different types of telescopes in use today first we have the refractor which uses lenses which you see behind me here next up we have the reflector which uses mirrors and third we have meketa dioptre that's a mouthful sometimes we just call it Schmidt Cassegrain remember what a telescope does it gathers light it focuses it to a focal point where the eyepiece then magnifies the image you want to see first up on the telescope list is the refractor of course since it was the first type of telescope invented remember Galileo back in the 1600s using the convex and the concave lens the light comes straight in and it goes straight out to the eyepiece which is great there's no obstruction in between the refracting scope also is great for viewing the moon and the planets has little distinct advantage in that area there's a couple more advantages with the refracting telescope first is lenses are a little easier to make than mirrors so you get a good quality image at a modest price second the lenses are in a sealed tube which makes the telescope pretty much maintenance-free I don't have I have a six-inch home-built refractor that I built out here now I left the high-tech one at home I've been building for the last couple years doing different types of telescopes another neat thing about the refracting telescope is the eyepiece here at the back of the tube you can easily mount a camera there for astrophotography this is a wonderful area to explore if you ever want to take pictures like the ones you see in those magazines now you've heard some of the good things about the refracting telescope what about some things that maybe aren't so great well first up you got this long tube design here why is that bad well first the bigger tube can get caught in the wind and of course move your image around which isn't very fun at all second with this long tube your eyepiece is lowered to the ground which means you would have to bend over more to see your image to correct that however you can get a larger tripod which will raise your telescope up higher so you don't have to bend over so much or you could get a right angle mirror here that you can attach to your telescope which will shoot the image up towards you and you can see it much better one last thing about refracting telescopes are any telescope for that matter please do not go to a department store and pick up a cheap telescope for $59 or something like that if you want a good telescope spend the money we recommend to $300 at a minimum to get a good scope make sure that you go to a reputable telescope or optics dealer to purchase your instrument our next telescope is the reflecting telescope ever look in the mirror remember Newton's reflector that we talked about earlier in the program this is it well actually this one's mine this is the same design though that Newton came up with over three hundred years ago it's just a light bucket a big light bucket collects a lot of light that's why it's great for observing deep sky objects like the ring nebula or the Whirlpool Galaxy the reflecting telescope uses two mirrors to gather and focus the light the first mirror is the primary mirror which is located at the back end of the telescope here that takes the light and reflects it to a secondary mirror which shoots it out the side of the telescope to the eyepiece where you can see your image remember that secondary mirror was Newton's bent that kept people from looking into the telescope and blocking out the image a couple great things about the Newtonian reflector you see here is first the folded light path when the light comes through the opening here it hits the primary mirror and is folded back creating a second light path this adds more light to the image that you're going to see this is better than the refractor which of course has just one single light path coming through another great thing about the reflector is the size issue the bigger the better works with the refracting telescope you have the lenses they get bulky and you get that color aberration with the reflector here you can get as big as you want and still have a great image a couple of the optical disadvantages with reflecting telescopes is first one called coma aberration what's that well when you're using mirror some of the images along the edge of the mirror can get a little fuzzy or hairy coma means hair thus the term coma aberration the second one is the secondary mirrors that can block out some of the light it's not much but it'll take away a little there's still great telescopes though now we're going to talk about telescope mounts a little bit later on in the show but I want to mention that Dobsonian mount that you see here because it pertains only to reflecting telescopes it's a great mount because it allows for portability it's easy to maneuver it's just this black base here and then your telescope and when you're looking at the I the base works very great with the telescope because you can just slightly move it left right or up down to find the image that you want to see all right that's two down and one to go in terms of types of telescopes we've taken a look at the refractor which uses lenses to bend and focus the light next up was the reflector which uses mirrors to gather and focus the light and last but not least is the cata dioptre or the schmidt-cassegrain well here it is Asham it Cassegrain telescope so how does it work well first off the light comes through a correcting lens here at the front of the telescope which refracts or bends the light back to a primary mirror at the back of the telescope which then reflects the light back up toward the front of the telescope off a secondary mirror which is at the back of the correcting lens here which reflects light then back through a hole in the primary mirror in out to the eyepiece the schmidt-cassegrain telescopes have some excellent advantages first because of their design they have very little chroma or coma aberration even though they both use lenses and mirrors since the light is folded three times within the tube the length of the tube can be quite short which is great for portability even in a small car they also focus fairly close so they lend themselves to photography and terrestrial use also the Schmidt Cassegrain are a closed tube system meaning they're relatively maintenance free like the refracting telescope the problem with a catadioptric or Schmidt Cassegrain telescope is the loss of light due to the folding of the light as it bounces from the primary mirror to the secondary mirror and then back to the primary mirror you'll notice the secondary mirror here will block some of the light coming in you can compensate for this by getting a larger telescope the aperture here or the opening is 8 inches across but commonly you'll see Schmidt Cassegrain is come in 12 or 16 inches which will give you the more light that you need or want while Schmidt Cassegrain telescopes are compact and easy to transport they often require hefty mount as you'll notice here even with an 8 inch telescope also if you'd like to do any camera work with the Schmidt Cassegrain telescope sometimes you might need a counterweight which also adds to your transport weight a great new thing about some of the Schmidt Cassegrain telescopes are the computer controls that you can get with them for example this computer pad right here will allow you to move the telescope for example west east or north south or maybe just punch in m31 and you get the Andromeda galaxy well these computer controls are great and you also can use laptop computers try to find some of the things on your own there's nothing like the joy of finding stuff in the night sky all by yourself and then showing it off to some friends so where's the best place to set your telescope or use your binoculars to see the night sky well first off you may not realize it but the city has an awful lot of light pollution so as much as you can get away from those city lights the difference is just dramatic I mean in the city you can see maybe you know twenty or thirty stars depending exactly where you are but if you get out to the country you can see thousands of stars and many more sky sights with your telescope to show you just how bad those city lights can be take a look at these two photos of comet hale-bopp taken by Loren Nelson the light pollution is quite obvious in the photo on the left taken in one of our city parks the photo on the right was taken a few nights later out in the country miles from the bright city lights not only is the comet much more vivid just look at all the other stars that can be seen from an area with little or no light pollution remember whenever possible take that hour drive and get away from the city lights here's a satellite photo of the United States at night which clearly shows the light pollution not only from our bigger cities but from many smaller towns as well if you'd like to know more about light pollution and the efforts to curb it you can check out the International dark-sky association's website will show their website along with other telescope manufacturers and suppliers at the the show now we've all heard the expression twinkle twinkle little star and this is an important fact when looking through the telescope oftentimes you'll see the star or planet or even the moon twinkle a little bit look at this image of the moon this is caused by our atmosphere it's always in motion and it takes the light of the object you're trying to see and makes it jiggle or jump around or twinkle so it's not the telescope's fault it's our atmosphere refractors provide excellent images of the moon and planets are fairly portable but usually cost more per inch of aperture than the others reflectors gather great amounts of light and are moderately priced they're particularly suited to deep sky viewing of galaxies and nebulae but they can be quite large and bulky and generally require more maintenance Schmidt Cassegrain are very compact even at large apertures they're excellent performers and well suited to astrophotography but they're not cheap and you can expect to pay at least $1,000 at the minimum now if you're like most of us you'll soon find that your basic telescope system as good as it is can benefit from a little accessorizing and believe me there are a lot of accessories to choose from first you have I piece 'iz and filters which can help your telescope improve the image that you're seeing and second you have star chards clock drives computer controls which can make things a little easier for you so you can enjoy a night under the stars so what about eyepieces remember how a telescope works the main lens or mirror gathers the light and focuses it to a point and this image is pretty small so then you need an eyepiece to magnify that image this is usually one of the first accessories someone buys after they get the telescope you usually get an eyepiece or two but it's nice to have a range of eyepieces so you can get different size images because eyepieces are lenses they have a focal point and the disc from the lens to the focal point is called the focal length and is usually measured in millimeters this is one of the numbers you'll see on different eyepieces eyepieces with short focal lengths in the 4 to 12 millimeter range provide high magnification but a narrow field of view eyepieces in the 13 to 26 millimeter range offer medium magnification and a medium field of view eyepieces with a long focal length of 28 millimeters or more provide a wide field of view but at a low power eyepiece is consists of several lenses which determine the eye relief remember the distance between your eye and the image that you're seeing so you can see it all and field of view which is how much of the universe you're seeing the eyepieces are originally named after the person who designed them the Kellner eyepiece is fairly inexpensive and is the standard eyepiece that comes with many telescopes it has a fairly narrow field of view of around 40 degrees the plus L is one of the most popular of today's eyepieces and is a good performer in the mid range of 15 to 30 millimetres a Nagler eyepiece offers a wider field of view than other eyepieces usually in the 55 to 65 millimeter range these are expensive eyepieces in the two to $300 range but you get what you pay for now there are a lot of eyepieces out there on the market and we've only taken a look at just a few of them so remember to check out your different telescope manufacturers and dealers so you can get the eyepiece that you need the first time you look into a telescope at a familiar object you may be surprised to find the images upside down and/or backwards this is due to the way the primary lenses or mirrors focus the light it can be easily corrected by adding and erecting prism before your eyepiece another eyepiece accessory you might want to look into excuse the pun is a Barlow lens this handy device is a negative lens system that can double or even triple them magnifying power of an eyepiece just remember anything you add to the light path will reduce the intensity of the light and possibly introduce ghosting or other optical aberrations still the Barlow lens is a good accessory to have filters are also great accessories for telescopes and they come in four main types you have the solar filter planetary filter Nebula filter and the neutral density filter and most of these filters will screw into the base of your eyepiece except for of course the solar filter which fits over the top of the telescope first let's talk about planetary filters these are relatively inexpensive colored filters that bring out the contrast of the imager trying to see for example you would use a yellow filter if you wanted to see the Great Red Spot and Jupiter a bit better and also use these filters to bring out the subtle markings on Mars and maybe even the subtler markings on the planet Saturn next up is the nebula filter but these filters do is black out the blue and yellow light that comes from the city street lights so sometimes they're called by anti light pollution filters they block out the yellow and blue leaving the red and green light that comes from most of the nebulas you see in space obviously you can't get rid of all the city lights but try to get away from them as much as you can and get to those dark skies in rural areas now we have a neutral density filter so what are these good for well they cut down on the amount of light coming into your telescope and these are great for the bright planets like Jupiter and Venus and the moon there are great also because they don't change the color tint of your image so you see what you're supposed to see you just don't see it so bright and last up on the filter hit parade is the solar filter this filter kind of looks like a mirror but actually it's a really dense filter to block out those harmful rays of the Sun including the ultraviolet and infrared rays so absolutely make sure if you're ever looking at the Sun you have a solar filter obviously you don't want to ever damage your eyes now if you don't have the money to buy a solar filter there is another way to look at the Sun it's called the projection method you may have done this as a kid when you looked at a solar eclipse what you do here notice our associate rodner doll out on the mall you're in downtown Minneapolis he's using the projective method by simply holding or placing a white card about a foot from the eyepiece and focusing the sun's image on that this is great for group observations as we do twice a year here on the mall since telescopes have such a narrow field of view it's pretty hard to find the object you want to see by just using your telescope unless of course you have the cash for computer controls so what do you do well get a finder scope and attach it to your telescope here's one this is just like a mini telescope it has a wider field of view you get the object you want to see put it right in the center at the crosshairs and bingo there's your image in the telescope now over here is the tail rad finder sculpt it works just like this one here but it uses a little red bull's eye you put your image in the center of the bullseye and presto it's in the eyepiece now the tripod that comes with your telescope doesn't need much of an explanation it's there to steady your scope what you want to do though is find level ground and make sure your tripod is level and then you'll be a-ok now most months for telescopes are the elf azimuth mount what does that mean L stands for altitude which means up or down and Asthma stands for left or right or more specifically the direction you're looking at you can control these by little knobs on the scope making the telescope go up or down altitude or left-right asmath of course you need to do this because the earth is rotating we rotate from west to east causing objects in the sky to go from east to west now of tracking the sky with your alt azimuth Mount is a little bit tiring for you you can move a step up the equatorial mount is designed to track the stars as they move left to right across the sky once the moon is polar aligned that is aligned with the Earth's axis you only have to adjust for altitude with the addition of a clock drive the telescope will track your chosen target without any additional guidance from you if you plan to do any serious Astro photography you have to have an equatorial mount with a clock drive one accessory you don't want to forget is the road map or star map to quote the late great Carl Sagan there are literally billions and billions of galaxies nebulas and stars out there and you need to know your way around on the simple level you can pick up a sheet star map like we sell at the planetarium here July starry nights shows you where the constellations are and a few deep sky objects or you can take a step up and get astronomy or sky and telescope magazine they have great star charts at the center of these magazines showing you where the different objects are that you might want to see or you couldn't get a book or a reference guide and there are literally thousands of them out there a great one is the Nortons 2000 star Atlas in reference handbook showing you where all the deep sky objects are plus telling a little more about them remember you need the road map or star map now when you're out there on a perfect moonless clear night far from city lights with your scope there's one thing you want to protect and that's night vision remember when we are talking before about how our pupils when they're out in dark skies they will widen they'll open up a little bit to adapt to the dark conditions to see your images that you want to see through your scope well if you turn on a light your eye or your pupil here is gonna shrink back down and it's gonna be harder to see the image you want to see in your scope so remember protect your night vision don't turn out any bright lights for first time telescope people don't turn the lights on for your spouse or whoever's outside to help them see it doesn't really help them I found that out so what do you do if you have to turn on the light especially say to read your star map well one thing you want to do is get a red flashlight like this one here now why would you use a red flashlight while our eyes are less sensitive to the red light part of the spectrum so you keep your night vision or you simply could use red cellophane and put it inside a regular flashlight just remember the astronomers rhyme red at night astronomers delight one problem you may have heard of with telescopes is Dew or condensation and this results from the warm air temperature inside the telescope here especially the Schmidt Cassegrain czar the refractors which are a closed tube system it's not so bad with the reflectors because they're open to in the air inside the telescope of the reflector can match the air outside so that's the problem a difference in air temperature that's how you get Dew or water droplets on your scope you can help prevent do by getting a dew shield like this and you just wrap it around the telescope right around the front lens here get it nice and snug and this will help match the air temperature inside the tube with the air outside it prevents it a little bit another thing you can do is get a heat coil these are kind of nice you just wrap this around your telescope too and it helps heat up the air around the tube to match the air inside the telescope sometimes you can even use a hairdryer which is kind of cool so there are ways to prevent do it's hard to eliminate it but you can't prevent it by matching the air temperatures inside the telescope and the outside air so how do you run one of these dew coils or a motorized clock drive if you're in the middle of a field in the middle of the night most accessories that need power are usually available in both AC and DC versions if you're always near electricity when you use your telescope you should get accessories that plug into standard wall outlets if you're going to be out in the middle of a field you'll need a rechargeable battery power sub why to run your electric accessories be sure to check your owner's manual for the recommended AC or DC operation now there's lots and lots and lots of accessories to numerous to mention that we didn't get into in this program but be sure to check out the magazines and the dealers and the manufacturers to get the latest and greatest accessories that you want and need all right you're all set you're in the middle of the field on a nice clear night you got your accessories you want you have your lens or mirror cleaned you have a chair you have star charts the right eyepieces what do you want to look at well first let's start with the brightest thing in the sky the moon in my experiences of showing the moon through the telescope to people it's the most fascinating object to see the craters are just wonderful the best time to see the moon is actually during the early stages the Crescent stages up to the first quarter when you get near the full moon it's almost too bright to see some of the fine details it's really neat to watch The Terminator we're not talking hard on Schwarzenegger here move across the moon the Terminator is where light meets dark and you can see shadows from the craters and the Highlands it's just real neat so start with the moon after you've checked out the moon the next stop are the planets which planets are visible in the sky well check the magazines find out where they are a neat one is the planet Jupiter with a good scope you can actually see the bands of Jupiter or the different cloud layers and the great red spot and don't forget Saturn's rings that also just blows people away venus isn't too bad you can actually see the Crescent phases on the planet Venus and Mars if it's close to the earth you actually sometimes can catch some surface features and even the polar caps mercury isn't much to the telescope Uranus and Neptune you can get some color on them not too bad Pluto or get it tiny white dot you need to be really good to spot blue after the planets you want to move out into the universe a little bit further and check out some of the stars some stars like the middle star of the big dipper's handle Mizar and Alcor actually a double star real neat through a telescope and there's another one in Cygnus the Swan it's called Albireo when you look through the scope you see a beautiful blue and gold star precious then move on to maybe star clusters like the double cluster in the constellation of Perseus they're just chunks of stars about a hundred to two hundred and just a real neat view after you look at some star clusters maybe a globular cluster like m13 and the constellation of Hercules these are all within our Milky Way galaxy and if you want to go beyond our Milky Way you can check out other galaxies probably the most famous one is the Andromeda galaxy or m31 of course in the constellation of Andromeda this is best seen during the fall and winter times check out other galaxies too maybe like the Whirlpool Galaxy and the sombrero galaxy there's so much to offer out there in the universe now after you've become a great telescope observer and know your way around the sky you might want to try Astro photography it's gonna take a little time and a little patience and yes a little cash but the efforts are well worth it and you may just get some pictures like in the magazines or in the books what you need of course first is a camera and you can either piggyback it on your telescope it's got a clock drive to get some great pictures or you can take the lens off and use an adapter and attach it to the telescope and now your telescope becomes like a lens and you can see some really nice images with your camera you also can try video that's way more expensive of course and CCD cameras which means charged coupling device which is electronic imaging a lot of the newer telescopes use that I come here today to do a little observing tonight we hope I do a little CCD imaging a video you're taking 30 per second or so let's see City camera you're using basically the same chip but you're just one exposure in minutes so you're like gathering light that whole time so give astrophotography a try and again you might just get those pictures like you see in the magazines so there you have it astronomy lovers that's our video we sure covered a lot and as you know there's a lot more out there we hope we answered a few of your questions but if you have more make sure you check out the resources remember the planetarium that's where I work will always show you a beautiful clear night sky show you the constellations so you can find your way around with your telescope or binoculars check out the local astronomy club they're the ones out there under the night sky and looking through the telescope and binoculars check out what they're using see if you like that maybe you want to upgrade also check out the internet it's a beautiful area to find out a whole host of information about telescope and binoculars sometimes too much information but give it a shot there's so much to see there's probably nothing more beautiful than starry night sky far from the city lights so take that telescope out there and never stop learning about this incredible inspiring universe it is truly magical

Channel: m4lvolio

Views: 47,929

Rating: 4.7333331 out of 5

Keywords: tutorial, education, astronomy, Telescope (Invention), Binoculars (Invention), Space, Planetarium (Building), Lesson, Teacher, Learn, Student, Lessons, School, Students, Teachers, Tutorials, Aliens

Id: ChyLgXVTmxw

Length: 52min 28sec (3148 seconds)

Published: Mon Jan 19 2015