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Posts tagged ‘telescopes’

Street Lights they are a’ changin’. How will telescope light pollution filters adapt?

For the hobby of astronomy, the biggest obstacle of all time is light pollution. Hands down. The more lights in yiour area, the less you will see.

We try to fight it when we can. Petition for lights that reduce upward glare, maintain some dark sky locations, and advocate for limiting new lighted areas. But on an individual level, there is only so much we can do to fight light pollution.

One of those things is to employ a light pollution filter.

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Repost: So you got a new telescope for the holidays – A new telescope owner’s primer

This is a repost of our usual post-holiday telescope primer for new telescope owners:

So you got a new telescope for the holidays: A Quick Primer for new telescope users.

Be it X-mas, Hannukah, Kwanza, Solstice or Giftmas this is the season for getting telescopes as gifts. Sadly, many of these scopes might be rushed into usage and some critical steps might be 016skipped. This can result in a frustrating experience for a budding young astronomer who may give up their new hobby prematurely. This can be avoided if you only take the time and a few precautions to make certain you get the baby steps out of the way without too much tripping and falling.

1) Do as much as you can during daytime first!

I can’t stress this too much. Many folks assume they can assemble their telescope right out of the box at their chosen viewing spot – in the dark. Suffice it to say this is not a good idea. Assembling out of the box at the viewing site might be an extreme example but you should certainly try working your scope and getting the ‘feel’ for it during the daytime as much as possible. Take your telescope outside during the daytime and point it at a nearby tree or other object (the object should be at least 1/4 mile away). Use this object to align the finder scope (see below) as well as test how the eyepiece focuses. Try changing your eyepieces between the low and high powered ones to see how that works as well. Move the telescope in large movements as well as using the slow motion controls as well. When you do these things in the daylight you can get a much better feel for how they should work than if you try them at night. Also if you drop an eyepiece or loosen a screw you have a decent chance to find it. Get your mistakes out of the way when the sun is up.

2) Assemble your telescope properly

This should go without saying, but it is amazing how many folks skip a few steps or don’t attach parts, or don’t read the instructions properly. We’ve seen telescopes in for “repairs” just after the holidays that were just put together wrong, or some critical final steps were ignored (slow motion controls not attached, counterweights not placed). Most of the time, there are very few non-critical elements of a telescope’s construction. So be sure to follow the assembly procedure carefully. Allow yourself a couple of hours as well (maybe three hours for certain models of dobsonian telescopes) for the assembly. Don’t assume you can just put it together a 1/2 hour before you plan to head out and view.

3) Align your finder scope. Align your finder scope! ALIGN YOUR FINDER SCOPE!

Get the point? Many folks ignore this step until the last minute and we can tell you that trying to work a telescope without an aligned finger is very,very, very hard. Even the lower 084magnifications on a short focal length telescope only see a little under 1 arc degree of the sky. This is a tiny portion of the sky so hoping to find an object with just the eyepiece is really hard to do. There is a reason why almost all telescopes come with a finder scope. So make sure to align it (During the daytime per suggestion #1) . If your telescope comes with a red-dot finder instead of an optical finder scope, be certain to carefully align that as well during the daytime – and don’t forget to switch it off! A dead battery in a red dot finder is nobody’s friend.

4) Did you get an Equatorial mount? Figure out how it moves!

An equatorial mount has some great advantages over a regular altazimuth (altitude-azimuth) mount. It can track, be motorized, and the larger ones can even be used with setting circles to locate objects in the night sky. But these are only true if you take advantage of the equatorial mount’s features and set it up properly. During the daytime (suggestion #1 again!) try a rudimentary set-up of the equatorial mount. This does not have to be super accurate as some telescope’s instruction manuals may require, just enough to get mostly accurate tracking for a little while. Perhaps more importantly, get a feel for how the telescope moves – you are used to moving things in an up/down left/right fashion. Now you need to get used to moving the telescope in declination and right ascension. Try moving the telescope from one target to another using the mount properly during the daytime to get a better sense of it. One thing to keep in mind is that the counterweight is there for a reason – it shouldn’t be pointing down all the time.

If you have a larger Equatorial mount keep in mind that you can use the setting circles to help find objects in the night sky with the help of a star atlas. But this means you have to learn to use it. Read your instruction manual carefully. You might also consider downloading a Sidereal Time app for you smartphone. You’ll see why once you figure out the details of using your Equatorial mount.

5) Choose your first targets wisely!

Many folks go out with their telescope and just point it at the brightest thing in the sky. This is fine if the brightest object is a planet or the Moon, as there is lots to see. But very often at this time of year the planets might not be out until very late and the brightest thing in the sky is the star Sirius. Problem is, Sirius is just a star and stars appear as just a point of light even when magnified through your telescope. This can be a very boring target and can be disappointing if it is the only bright object. So make certain before you go out for your first night’s viewing that you know what will be up! Most telescopes these days come with some rudimentary planetarium software that can show you what the sky will be like on any night. Failing that there are online websites that do the same thing (sometimes better). Planispheres can also be used, and if you have a Smartphone or pad you should download a planetarium app like Google Sky (its free). Depending on what time of the month it is, the Moon may not be up during evening hours. Since we suggest the Moon as a great first target for your telescope you might want to wait for it. Failing that, try to look for the brighter planets.

6) Got a computerized telescope? Take advantage of free smartphone apps to make it much easier to set up!

We’ve been kind of ‘meh’ about computerized telescopes in the past, and are still a bit wary of a telescope where 70% of the cost is in the computer andGoogleSky motors and not the optics. But we have softened a bit since they have become a bit easier to use – and not because they changed, but rather our phones did.

Computerized telescope makers kind of make it seem like a computer means your telescope will magically find things in the night sky. All you need to do is toss it into your yard and enjoy the viewing. But that is not how they work. To set up the telescope’s computer you need to point it at two named stars so it can calculate where everything else in the night sky is located. This used to mean that to set up the telescope you had to have good knowledge of the night sky to find those stars -which kind of defeated the purpose.

But now smartphones are ubiquitous these days and there are plenty of planetarium apps out there for free that will help you identify those stars. Smartphone planetarium apps are not super-accurate (they can be off by as much as an hour)  but they will help you spot and identify bright stars that you need to aim your telescope at to orient the computer.  This makes the computer orientation much easier to do than trying to learn to use a planisphere or star map on the fly.

7) Learn, learn learn!

There’s a host of information for astronomy newbies on the internet and in books. Amateur astronomers are very keen on sharing their knowledge and experience with you. Check out the major magazines online websites such as Sky & Telescope or Astronomy. There are a zillion astronomy websites with forums as well you might wish to peruse. Even on this blog we have a collection of Telescope Tips you should check out for helpful advice. Also consider joining or at least contacting your local astronomy club – you can find all kinds of help from them, as well as many other benefits from membership (such as loaner equipment).

If your first night with your telescope is a good one, then you’ll have a much better time with the hobby. But always remember a little planning goes a long way!

Happy New Year!

Interested in buying telescopes?

www.spectrum-scientifics.com

REPOST: The Spectrum Scientifics Telescope Buyer’s Guide

The holidays mean less time for blog posts and more people looking into buying their first telescope. With this in mind we are reprinting our telescope buyer’s guide for the season:

Spectrum Scientifics Telescope Buyers Guide

There are several telescope buyers guides available on the Internet, some good, some not so good. At Spectrum we are writing from our experience with customers and hope to make this simple and helpful.

Towards that end, the first and in some ways only rule of telescopes is:

Aperture is King!

Aperture is the diameter of the main lens or mirror of the telescope. The bigger it is, the more light the telescope gathers. Do not judge a telescope by its magnification, and stay away from any brand of telescope that sells itself on excess magnification claims (300x!, 600x!, etc.). This is sure sign of poor quality.

More light gathering means better, brighter images, assuming all other things being equal. Decent commercially sold telescopes usually start about 60mm in size (about 2.3”) and go to 20” diameter or more. Roughly speaking, every 2 extra inches of aperture doubles the light gathering capacity of the telescope.

The big problem with getting more aperture is that it increases the size and weight of the telescope. Having a huge, giant telescope with lots of light gathering power has little benefit if it is so heavy you never want to take it out and use it! A minor, but critical caveat to the ‘Aperture is King’ rule is that the small, portable telescope that gets used all the time is more powerful than the giant telescope that never gets moved out of the garage.

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Telescope Technology – why it seems so far behind sometimes?

Every now and then we get someone asking the question ‘Why can’t a computerized telescope do ‘x’?’ Usually ‘x’ is ‘find things in the night sky without me having to work at it’.

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The answer, as is often the case, is complex.

When computerized telescopes first started being mass marketed (many computer systems existed as add-ons or on high-end telescopes and as early as the 80’s) they general impression given by their marketing was that they did everything for you. No aligning the finder, no two star alignment system. Just toss the telescope onto the grass lawn and start watching. This was pretty much a lie, and many folks soured on telescopes as a result. The marketing tried to be a bit more clear as other companies added different computer options, but what most folks wanted auto-alignment and tracking. So what went wrong?

  • 1) What people are comparing it with is not exactly accurate

Many folks are stumped by how they can have a planetarium program on their smartphone (or tablet) that gives them googleskymapscreena good idea of what they are looking at in the night sky. What they don’t realize is how innacurate those programs are. They give you a general idea what is up there, sure, but the next time you use it look at just how far off it actually is. The programs can be as much as an hour off, and when you telescope is cranked up to 120x and is looking at 0.05 degrees of the night sky a miss is as good as a mile. Your smartphone does an approximation based your location, the time, and how the tilt sensors are reading. But those sensors aren’t perfect  and the GPS positioning can go awry very easily. Some advanced astronomer  may use planetarium programs by having Pads or phones attached to their telescope, but these are used as more of an adjusting, high detailed star map than as a direct guard

  • 2) The Telescope Manufacturers aren’t exactly rolling in loads of research cash

GPS companies, smartphone manufacturers, Pad manufacturers all have one thing in common: They aren’t small companies. Apple is a mutli-billion dollar company, Google (who developed the droid system) isn’t exactly poor, Samsung, LG, etc. Even when these companies are having hard times they aren’t exactly small. And they spend tons of money trying to stay on top.

Telescope comapnies, by comparison, are on the smaller side. A telescope company that has more than 100 employees is probably a bit bloated. Development and engineering crews are probably in the single digits, with some outside contractors being hired as needed. So this means telescope manufacturers aren’t going to have bleeding edge tech to work on and with. Even when they do get a good idea, it can take a long time to develop & bring to the market.  And it will probably use up a large amount of the research budget. An example would be Celestron’s SkyProdigy series, which while it would have been much more expensive to develop 10 years ago was still probably not an easy developement cycle. And this bleeding edge tech does not ensure success. The SkyProdigy is fairly expensive (smaller models were dropped some time ago), and may not work as well as claimed.

The thing is, almost all of us carry some kind of cell phone, if not a smartphone so the market is huge (even then some phone makers have embarrassing failures). But with telescopes the market is limited, there is no ability to take loss leads on the telescopes becuase the customer will subscribe to an astronomy plan. If a product comes on the market it needs to earn its way in sales and margins.

  • 3) That said, there is some seriously backwards technology on telescopes

Pretty much all computer guided or controlled telescopes include some sort of hand-controller. This usually connects with an ethernet cable to the telescope itself. No problem, ethernet cable is still well in use, even in an age of everything being wireless. But suppose you want to RS232run the telescope from your laptop using a planetarium program like Starry Night or something? You’d need a cable to run that, sure, but what kind? You’d probably think some kind of USB cable, and probably one of the bigger sizes like USB.

Nope.  Odds are you have to connect to your laptop using a RS232 cable. That’s right, old pin and socket tech from the 90’s. These are connection systems that started to go out of style in computer design with the introduction of the first iMac and yet even some of the most modern of telescopes has this connector. Keep in mind that laptops got rid of this connector as soon as they could (pin connections are a big space waster).

Even on less computer gadget features, inconveniences can rule the day. Most reflector telescopes designed after 1999 usually have easy-to-handle knobs on the back of the optical tube for aiding in collimating the telescope’s mirror.

2016-06-14 14.15.49

These knobs are convenient, have a nice grip, and are much easier to turn. But here is the back of a computerized telescope that, while modern in design, uses an off-the-shelf tube that has an older screw-based collimation system.

2016-06-14 14.16.10

Le sigh.

www.spectrum-scientifics.com

 

5 Tips to use an Telescope with an Equatorial Mount (the easy version)

In past entries in this blog we have discussed the merits Equatorial Mounts vs Altazimuth mounts on telescopes, but we never actually went into much 016detail on how to properly use one of these mounts. Here are some basic hints for a beginner first trying to use an equatorial mount. Note that this are not hints for precision alignment – they are strictly for the beginner so they do not get overwhelmed! Speaking of which

1) Keep you mount setup as simple as possible at first.

Look at telescope instructions for equatorial mounts and you’ll see a lot of information on adjusting setting circles, using a polar axis scope, and other heavy duty details. Here’s a hint: If you don’t plan on doing astrophotography or long, long viewing sessions you don’t need all of that setup! Here is what you need to do:

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Updated Repost: So you got a new telescope for the holidays – A Quick Primer for new telescope users.

This is an updated repost of our popular new telescope owner Primer. We’ve added a few bits concnering new attitudes on computerized telescopes and a few other minor tweaks. Be sure ot pay attention when you first use your telescope. Locally, most folks probably haven’t since I don’t think we’ve had a clear night since the 25th.  Anyway, read-on and learn!

So you got a new telescope for the holidays: A Quick Primer for new telescope users.

Be it X-mas, Hannukah, Kwanza, Solstice or Giftmas this is the season for getting telescopes as gifts. Sadly, many of these scopes might be rushed into usage and some critical steps might be 016skipped. This can result in a frustrating experience for a budding young astronomer who may give up their new hobby prematurely. This can be avoided if you only take the time and a few precautions to make certain you get the baby steps out of the way without too much tripping and falling.

1) Do as much as you can during daytime first!

I can’t stress this too much. Many folks assume they can assemble their telescope right out of the box at their chosen viewing spot – in the dark. Suffice it to say this is not a good idea. Assembling out of the box at the viewing site might be an extreme example but you should certainly try working your scope and getting the ‘feel’ for it during the daytime as much as possible. Take your telescope outside during the daytime and point it at a nearby tree or other object (the object should be at least 1/4 mile away). Use this object to align the finder scope (see below) as well as test how the eyepiece focuses. Try changing your eyepieces between the low and high powered ones to see how that works as well. Move the telescope in large movements as well as using the slow motion controls as well. When you do these things in the daylight you can get a much better feel for how they should work than if you try them at night. Also if you drop an eyepiece or loosen a screw you have a decent chance to find it. Get your mistakes out of the way when the sun is up.

2) Assemble your telescope properly

This should go without saying, but it is amazing how many folks skip a few steps or don’t attach parts, or don’t read the instructions properly. We’ve seen telescopes in for “repairs” just after the holidays that were just put together wrong, or some critical final steps were ignored (slow motion controls not attached, counterweights not placed). Most of the time, there are very few non-critical elements of a telescope’s construction. So be sure to follow the assembly procedure carefully. Allow yourself a couple of hours as well (maybe three hours for certain models of dobsonian telescopes) for the assembly. Don’t assume you can just put it together a 1/2 hour before you plan to head out and view.

3) Align your finder scope. Align your finder scope! ALIGN YOUR FINDER SCOPE!

Get the point? Many folks ignore this step until the last minute and we can tell you that trying to work a telescope without an aligned finger is very,very, very hard. Even the lower 084magnifications on a short focal length telescope only see a little under 1 arc degree of the sky. This is a tiny portion of the sky so hoping to find an object with just the eyepiece is really hard to do. There is a reason why almost all telescopes come with a finder scope. So make sure to align it (During the daytime per suggestion #1) . If your telescope comes with a red-dot finder instead of an optical finder scope, be certain to carefully align that as well during the daytime – and don’t forget to switch it off! A dead battery in a red dot finder is nobody’s friend.

4) Did you get an Equatorial mount? Figure out how it moves!

An equatorial mount has some great advantages over a regular altazimuth (altitude-azimuth) mount. It can track, be motorized, and the larger ones can even be used with setting circles to locate objects in the night sky. But these are only true if you take advantage of the equatorial mount’s features and set it up properly. During the daytime (suggestion #1 again!) try a rudimentary set-up of the equatorial mount. This does not have to be super accurate as some telescope’s instruction manuals may require, just enough to get mostly accurate tracking for a little while. Perhaps more importantly, get a feel for how the telescope moves – you are used to moving things in an up/down left/right fashion. Now you need to get used to moving the telescope in declination and right ascension. Try moving the telescope from one target to another using the mount properly during the daytime to get a better sense of it. One thing to keep in mind is that the counterweight is there for a reason – it shouldn’t be pointing down all the time.

If you have a larger Equatorial mount keep in mind that you can use the setting circles to help find objects in the night sky with the help of a star atlas. But this means you have to learn to use it. Read your instruction manual carefully. You might also consider downloading a Sidereal Time app for you smartphone. You’ll see why once you figure out the details of using your Equatorial mount.

5) Choose your first targets wisely!

Many folks go out with their telescope and just point it at the brightest thing in the sky. This is fine if the brightest object is a planet or the Moon, as there is lots to see. But very often at this time of year the planets might not be out until very late and the brightest thing in the sky is the star Sirius. Problem is, Sirius is just a star and stars appear as just a point of light even when magnified through your telescope. This can be a very boring target and can be disappointing if it is the only bright object. So make certain before you go out for your first night’s viewing that you know what will be up! Most telescopes these days come with some rudimentary planetarium software that can show you what the sky will be like on any night. Failing that there are online websites that do the same thing (sometimes better). Planispheres can also be used, and if you have a Smartphone or pad you should download a planetarium app like Google Sky (its free). Depending on what time of the month it is, the Moon may not be up during evening hours. Since we suggest the Moon as a great first target for your telescope you might want to wait for it. Failing that, try to look for the brighter planets.

 

6) Got a computerized telescope? Take advantage of free smartphone apps to make it much easier to set up!

We’ve been kind of ‘meh’ about computerized telescopes in the past, and are still a bit wary of a telescope where 70% of the cost is in the computer andGoogleSky motors and not the optics. But we have softened a bit since they have become a bit easier to use – and not because they changed, but rather our phones did.

Computerized telescope makers kind of make it seem like a computer means your telescope will magically find things in the night sky. All you need to do is toss it into your yard and enjoy the viewing. But that is not how they work. To set up the telescope’s computer you need to point it at two named stars so it can calculate where everything else in the night sky is located. This used to mean that to set up the telescope you had to have good knowledge of the night sky to find those stars -which kind of defeated the purpose.

But now smartphones are ubiquitous these days and there are plenty of planetarium apps out there for free that will help you identify those stars. Smartphone planetarium apps are not super-accurate (they can be off by as much as an hour)  but they will help you spot and identify bright stars that you need to aim your telescope at to orient the computer.  This makes the computer orientation much easier to do than trying to learn to use a planisphere or star map on the fly.

 

7) Learn, learn learn!

There’s a host of information for astronomy newbies on the internet and in books. Amateur astronomers are very keen on sharing their knowledge and experience with you. Check out the major magazines online websites such as Sky & Telescope or Astronomy. There are a zillion astronomy websites with forums as well you might wish to peruse. Even on this blog we have a collection of Telescope Tips you should check out for helpful advice. Also consider joining or at least contacting your local astronomy club – you can find all kinds of help from them, as well as many other benefits from membership (such as loaner equipment).

If your first night with your telescope is a good one, then you’ll have a much better time with the hobby. But always remember a little planning goes a long way!

Happy New Year!

Interested in buying telescopes?

www.spectrum-scientifics.com

 

 

A brief listing of terms used when reviewing telescopes

Open up a copy of Astronomy magazine, or Sky & Telescope, or just check out the innumberable online astronomy websites and you’ll see loads of 021reviews of telescopes on the market with lots of terms being tossed around that many a new telescope shopper may not be familiar with. This blog post will strive to list as many (but by no means all) of the terms used by telescope reviewers that might be confusing to novice telescope buyers.

Undermounted – This criticsm means the the optical tube (the part you look through) doesn’t have enough support from the tripod or telescope mount. The mount is, for one reason or another, simply not strong enough. The result of an undermounted telescope we be wobbly tripod legs, a telescope tube that shakes very easily in wind or by touching it, not moving smoothly as well as a host of other issues. Many cheap no-name telescopes are undermounted and it can be a crucial issue.

Overmounted: A lot rarer than undermounting, here the telescope’s tripod or mount is way over-engineered for the optical tube. This isn’t really going to cause problems except that the extra mount & tripod are going to add weight that isn’t needed.

1/4 wave, 1/10th wave, 1/8th wave: These terms are used to describe the optical accuracy of a telescopes optics. Put simply, the # fraction of wave (actually should be wavelength) is the amount of optical ‘error’ introduced due to irregularities at the telescope’s mirror (or lens) surface. Idaelly the optics of the system should have no more than 1/4 wave error cumulative by the time it reachs your eye. This includes the other mirrors in a telescope such as the secondary mirror in a refarctor or a glass plate on a Cassegrain telescope (errors are cumulative, so a telescope with 1/8 wave accuracy in its primary and secondary mirror will have a 1/4 wave error total . These terms are not used as much any more as a few years ago it ewas discovered that many of the claimed accuracies weren’t as described.  Instead the term used today is:

Mirror cell designs will vary

Mirror cell designs will vary

Diffracftion Limited: This term is used instead, and it simply means that when all things are set properly (mirror clean, optics aligned, etc) that the instrument will be able to resolve as well as it theoretically should. How well it can resolve depends on the size of the optics but the formula for that assumes a properly made mirror, etc. Diffrraction Limited was a lot easier for telescope companies to promise than 1/8th wave mirrors and the like.

Grab-N-Go: More a description of a type of telescope than a criticism. A grab-n-go scope is usually a small tube telescope that fits in a small carry case (usually a soft case, but by no means always) and operates off a very small mount or an easy-to-carry camera tripod.  The idea is convenience: preperation and setup is minimal and mutliple trips to the car are not needed.  It is the polar opposite of:

Big Iron/Light Bucket/other terms that sound large: These terms are used to describe larger telescopes swuch as big Cassegrain telescopes or larger Dobsonian telescopes. They are big, they are heavy. They often take up a lot of space in the garage, the biggest ones need their own trailers, and setup time may take a while.

Packing Grease: Sometimes referred to as Chinese packing grease as most telescopes are made in that country and the infamous grease seems to be unique to their productions. Some reviews complain about the stuff, which is primarily used on the focuser of the telescope. The grease is thick, and yet manages to be both slippery and sticky at the same time. many new telescope owners end up with some on their hands the first few times they use their telescope. The stuff can be annoying, but it works and keeps parts from seizing up or rusting.

This list is by no means complete, but can be helpful to those new to the astronomy hobby and are confused by the terminiology used by telescope reviewers.

www.spectrum-scientifics.com