Optics Blog

Great little telescope

2012-02-13T09:47:00.003-06:00

Wonder or wonders! We had a clear sky, Sunday evening, Even though the temperature was in the single digits, the stars were calling to me. Cold or no cold, when you get a clear night in our area, you don’t pass up a chance to setup & use a telescope.

How do you choose the right telescope for a cold winter’s evening? If you’re an old gal like me who seems to have less resistance to the cold with each passing year, you choose the telescope that can be setup and ready to go the fastest. If I have to spend a half hour in the cold assembling a telescope, my hands are already too cold to work the focuser on the telescope, even when I wear gloves.

Out came my little Apogee/LOMO 80 mm APO refractor. It did not disappoint. The Orion nebula was so beautiful in the telescope eyepiece that I just had to share the view with my husband, Bill. At 80x, compliments of my Televue Nagler 12.0 mm eyepiece and Televue Big Barlow, I could easily see the cluster of stars embedded in the nebula known as the Trapezium. Adding a Televue Bandmate OIII filter showed even more detail in the nebula. Wow!

My half hour was up - my hands were cold. It was a great thirty minutes, though. I went to sleep with a smile on my face, thanks to the sight of the Orion Nebula in that great little telescope.

Astronomy class

2012-02-10T09:51:00.004-06:00

Curious, enthusiastic and eager are words we typically use to describe the young, but how about curious, enthusiastic and eager seniors? Let me tell you, right now, that if you don’t think of seniors this way, you are guilty of stereotyping and you do this group an injustice. The seniors I am teaching, right now, for instance, are as eager and enthusiastic to learn about astronomy, telescopes and binoculars as any youngsters I have taught and I am a former middle school science teacher. It’s been an absolute teacher’s dream to share my knowledge of astronomy with this local group of very eager and curious seniors, this past week. Wonderful students!

In my experience, all of us, young and old, have a natural curiosity of the night sky and I have yet to meet a single person who would pass up an opportunity to look in a telescope eyepiece to gaze upon some of the wonders of the universe.

It’s our birthright, after all. As long as humans have been humans, we’ve looked and wondered at a night sky filled with stars. Our knowledge continues to grow and we now have a media that keeps us informed of the latest discoveries on an almost daily basis, but the need to see what’s out there with our own two eyes remains. Fortunately, this easily done thanks to telescopes, telescope accessories and astronomy binoculars that anyone can afford. There’s never been a better time to pursue an interest in astronomy right from your own backyard.

Amateur astronomy is alive and doing well and my class of seniors bears it out.

About the pic: M64, a galaxy in the constellation Leo, courtesy of the Hubble.

Computer or no computer on my telescope?

2012-02-09T10:14:00.003-06:00

Astronomers tend to either love the idea of computers on their telescopes to help them find objects in the sky or they tend to hold their nose at the idea of relying on a computer to find objects for them. There are, however, a few old pro astronomers like me who take the middle ground and see computers on telescopes as just another tool that may be helpful in certain situations.

I personally prefer to do without a computer on my telescopes because I regard finding objects in the sky the old-fashioned way – with a star atlas - instead of a computer to be part of the fun. Being able to work your way through hundreds of stars to center a tiny galaxy in the telescope eyepiece with nothing more than a star atlas as your guide is a thrill for me. It keeps me sharp and my telescope skills at their peak. Using a computer to help me find objects never even crossed my mind for many years because I had always had a sky filled with many stars to guide the way.

Then I found myself under Chicago’s badly light-polluted skies. The old familiar method of hopping from star to star to find objects I wanted to see in the telescopes and astronomy binoculars became more of a nightmare than a challenge. When light pollution robs you of your ability to detect a lot of those stars that you need to guide the way to your favorite objects, the old methods don’t work so well at all, even for an old pro like me. Meanwhile, as I struggled and sweated, my astronomy pals with their computerized telescopes were happily moving from one object to the next at an enviable pace.

Computer or no computer is one of those telescope first questions you should ask when trying to choose the right telescope, because it's always cheaper and more practical to buy a telescope with a computer, up front, than it is is to add a computer, later. My advice for urban dwellers that have to contend with some serious light pollution is to go with a computerized telescope, especially if you are new to astronomy.

On the other hand, I do strongly believe that everyone who takes the time to setup & use a telescope owes it to themselves to become thoroughly familiar with the night sky at least to the point of knowing and recognizing basic constellations and brighter stars without relying on a computer. That kind of knowledge makes for a better astronomer, with or without a computer on the telescope.

Red dot sights and rifle scopes

2012-02-08T10:09:00.004-06:00

As my eyes get older, I more and more appreciate the effectiveness of optics on firearms. No doubt about it, red dot sights, rifle scopes and pistol scopes make you a better shooter and bring out more of the accuracy any firearm has to offer. Next to ammo, optics are easily the most important gun accessories you can buy.

I’m primarily a pistol shooter and have always leaned toward shooting pistols because of the challenge. I bought my first pistol when I was eighteen. I was helping my younger brother on his trap line. We had enough gear to carry as it was and neither of us wanted to mess with a rifle. He couldn’t legally carry a pistol because of his age, but I could, so we bought a Ruger Single Six 22.

Little did I know that I would be the one to get the shooting bug, but I did, and I have been shooting pistols off and on, ever since. Yes, there were years when there were no guns and no shooting, either because we couldn’t afford to shoot or because we lacked a place to safe shoot, but sooner or later, I always managed to find my way back to the shooting range to do some target shooting.

My husband and I are definitely in the shooting mode, these days. We make almost weekly trips to the range, even in the dead of winter. I’ve been doing the teaching, which is kind of a switch from the typical husband and wife shooting team, but my Bill has proven to be an excellent student, but those darn iron sights have been giving him fits.

That brings me back to red dot sights and pistol scopes. What a difference they have made in his shooting! From a rest, he is now punching almost quarter-sized holes in the bull at 50 feet with our scoped 22 target pistols, shown in the pic, above. Time to move him off the bench rest position into more challenging shooting positions.

As for me, I still love to shoot iron sights, so I tend to spend most of my time with our iron-sighted handguns. Shooting pistols and handguns will always mean iron sights to me, maybe because of that first pistol I bought and shot when I was eighteen.

Telescope work of art

2012-02-07T13:07:00.003-06:00

Dobsonian telescopes were invented in the spirit of keeping things cheap so that everyone who wanted a good-sized telescope could afford one rather than having to settle for a small telescope. In that respect, Dobsonian telescopes have been a rousing success. To this day, a “Dob” remains the best value in terms of dollars spent per inch of telescope size, meaning you can often buy a telescope twice the size with a Dob with the same dollars you would spend on another design.

Who would have thought, then, that these simple telescopes would evolve to a point of becoming telescope works of art and, in some cases, expensive works of art? I am the proud owner of one of these in my Obsession 12.5” Classic. All wooden parts are made of cabinet-grade wood of a type specifically designed for use in telescopes. All metal parts are of the highest quality. Optics? Well let’s just say that the primary mirror alone costs more than a good telescope. Using cheap telescope accessories, then, would be a sacrilege with this telescope.

Now, why would anyone pay for this kind of quality in such a simple telescope design when cheaper materials and more reasonably priced optical components could very nearly get you the same performance? I’ve owned much cheaper Dobs and fell in love with the design many years ago, but I've always wondered what it would be like to build one of these telescopes with the very best of everything.

Now I know and I have not been disappointed. It’s a thrill to use a telescope work of art.

telescopes as spotting scopes

2012-02-06T10:42:00.004-06:00

High grade, small, short focal length APO refractor telescopes that serve double duty as astronomy telescopes by night and spotting scopes by day are well-respected tools in both the astronomy community and the birdwatching community.

I especially like these telescopes for bird watching. If you’ve never looked through a TV-85, Stellarvue SV80ED or my LOMO/Apogee 80 mm APO setup on a tripod to view distant and/or small birds at a lake or marsh, you are missing something. When conditions allow, you can easily exceed the 60x that is all you can squeeze out of a typical birding spotting scope. It’s quite a kick to make a positive ID on a bird at 80x or even 100x when everyone else is still guessing at 60x. Views at more conventional magnifications when using premium telescope eyepieces are just plain breathtaking with these telescopes, too.

It ain’t all roses with these telescopes as spotting scopes, though. They’re heavy - far too heavy to throw over your shoulder and hike a couple miles. Use these telescopes when you do your birding from a parking lot or viewing area near a parking lot, as many of us do. Weight is not a factor, then.

You’ll also be using 90-degree diagonals in these telescopes turned spotting scopes, so viewing will not be at a more comfortable 45 degrees as with conventional angled spotting scopes. Images will also be reversed, right-to-left, though still upright, but that issue is easily accommodated with a little practice. Yes, you can get imaging erecting, 45-degree prisms to use with these telescopes, but I do not recommend them because they noticeably degrade image quality. Stick with high-grade 90-degree mirror diagonals and you’ll get all the amazing image quality these telescopes have to offer.

Don't forget astronomy with these telescopes when you're done birding for the day.

About the pic: my LOMO/Apogee with Televue Nagler eyepiece and Stellarvue Enhanced 2 " diagonal. Awesome viewing up and down the lake!

Choosing telescope eyepieces

2012-02-03T11:40:00.004-06:00

It must be a little daunting for someone new to astronomy and telescopes to discover just how crazy some of us old pros get about telescope eyepieces. Here you are, an eager beginner and you’ve gone to all the trouble to choose the right telescope and then you find that there is even more to ponder about telescope eyepieces.

What is the best telescope eyepiece? Oh, if it were only that simple. Your choices in this all-important of telescope accessories is as personal and subjective as your choice of a telescope, perhaps even more so. Simply put, we astronomers tend to choose eyepieces based on the quality of the images they produce and quality is very much in the eye of the beholder. Some of us want crisp images, some of us want bright images and some of us want big, wide fields of view and some of us want all of those in a single telescope eyepiece and we'll pay whatever it takes to get it. It can be done, but it doesn’t come cheap.

Ignorance is bliss, and definitely cheaper when it comes to telescope eyepieces. If you’ve never used a great telescope eyepiece, you don’t know what you are missing and you’ll likely wonder who in their right mind would pay almost as much for a single telescope eyepiece as a decent telescope. Once you’ve had a chance to experience the view in a great telescope, though, you’ll understand. You’ll find yourself dreaming of magnificent views of the sky you saw and you’ll be hooked. Welcome to the club!

Quarter moon

2012-02-02T09:37:00.003-06:00

Beautiful quarter moon, last night, when I stepped out the door to do my usual after-dinner check of the sky, so I grabbed one of my small refractor telescopes for a closer look. I wasn’t expecting too see much as far as detail, though, because there was a classic ring of light around the moon that indicated a lot of ice and moisture in the air and that always makes it tough to see a lot of detail in the telescope eyepiece.

That proved to be the case, but I can’t say I was terribly disappointed. The moon peering through that icy shroud was truly beautiful and I didn’t need a telescope to enjoy it. I’m as die-hard as any amateur astronomer, but I love a good view of the sight sky with or without my telescopes or astronomy binoculars. If the day ever comes when I turn my back on such a lovely sight because I can’t use a telescope or my astronomy binoculars, then I might as well just stay indoors and watch TV.

Not a chance! ☺

Telescope portability, the traveling astronomer

2012-02-01T09:58:00.004-06:00

As much as we love living in northern Wisconsin, I can’t say much for its potential for amateur astronomy. Clear nights without clouds are especially rare in the winter and when we do get clear nights in any season of the year, sky transparency is typically only fair due to the high humidity. Okay, what does a die-hard astronomer do when she needs better skies for her telescopes and astronomy binoculars?

She goes on an astronomy trip to a location that does have better skies, that’s what. Time to load up a telescope and the binoculars in car, then, and travel west to a drier climate. Traveling is not an unusual remedy for an astronomer who suffers poor skies, by the way. A lot of city-bound astronomers under light-polluted skies travel to better locations on a regular basis. Some astronomers even make a yearly pilgrimage to distant regions famous for their pristine skies. That might seem like a lot of effort to get better images in a telescope, but only if you don't happen to be an astronomer. When it comes time to setup & use a telescope, experienced astronomers know that the quality of skies at your location is often more important than the telescope you use. A good sky makes all the difference when it comes to what you see in the telescope eyepiece.

This approach is where it makes sense to choose the right telescope, carefully. Portability is all-important in a telescope that will travel, as is a measure of ruggedness. My favorite telescopes for astronomy on wheels has always been short-focal length, high-grade APO refractor telescopes (see the pic), but this is also where Schmidt-Cassegrains and Maksutov telescopes really shine because they pack their optics into short, compact optical assemblies.

Time to break out the road map and plan my trip.

Dobsonian telescopes

2012-01-31T09:42:00.003-06:00

The best laid plans of mice and astronomy gals often goes astray. Okay, kind of corny, I know, but it is true when it comes to my big Obsession12.5” Dobsonian telescope. I love this telescope. It is a superb telescope. It leaves all my other telescopes in the dust when it comes to finding hard to detect, faint objects and everything it shows in the telescope eyepiece, it shows beautifully. It’s just that it is, well, a pain in the butt to use in the snow. It's my baby.

If you are not familiar with Dobsonian telescopes, what makes a Dobsonian (or Dob) a Dob is the mount, not the optics. This type of telescope does not use a tripod as part of the mount as with all other types of telescopes. Rather, the telescope sits on a flat box, or cradle.

Right now we have nearly a foot of accumulated snow in the yard and that is a fairly normal state of affairs for us in a northern Wisconsin winter. With my other telescopes, it is no big deal to setup & use a telescope in the yard because they sit on tripods. Just stick the tripod legs in the snow and away we go. Not so with my Dob. No matter where I place it, I have to shovel some snow and do it, carefully, too, because part of the optical system on a Dob is very close to the ground. Allowing the very expensive primary mirror to encounter snow and ice is a big no-no.

There is a solution, though it is one I’ve tried to avoid for the sake of cost. This telescope needs an observatory with a roll off or removable roof. That’s about the only way my precious Dob will see much use in the winter. Looks like my husband, Bill, will have another project on his hands this summer. :)

Mysteries in the telescope

2012-01-30T13:12:00.003-06:00

The truth really is stranger than fiction and if you want to experience that, all you have to do is look through a telescope eyepiece or astronomy binoculars. New discoveries in astronomy occur almost daily and today’s news is already outdated by the time you hear it. The sky is filled with unexplained mysteries and many of them are actually visible in backyard telescopes. Space is the final frontier, according to those old Star Trek episodes. Okay, I don’t know about that, but it is one frontier of science that is accessible to non-scientists.

That sense of mystery is one of the motivations I have to setup & use a telescope in the cold of a north-country winter or endure the mosquitoes in a north woods summer. I can give you a general description of the things I see in the telescope or binoculars, but I’m by no means a professional astronomer. If you want the latest update on such things, you will need to delve into scientific journals. That’s okay, though. Just knowing that much of what I see in the telescope manages to challenge known theories in astronomy is enough to keep things very interesting.

Beauty in astronomy

2012-01-27T11:06:00.003-06:00

Beauty is in the eye of the beholder, to be sure, but I’ve yet to meet someone that has not been impressed with the beauty of some of the objects I show them in myastronomy binoculars and telescopes. Whether it’s an alien moon landscape, an immense nebula of gas and dust or a glittering open cluster of stars, I always get plenty of oohs and ahs from my guests.

This sort of thing convinces me all the more that people go to all the trouble to choose the right telescope for aesthetic reasons as much as they do out of scientific curiosity for what’s out there in the universe. To be sure, a lot of my own observing is a bit esoteric in that I sometimes get lured into the hunt to find nearly impossible to see objects that often appear as little more than faint specks or smudges in thetelescope eyepiece, but even those objects are beautiful when you consider what they actually are.

All this is my way of saying that if you have been thinking about trying your hand at astronomy and you are not especially technical by nature, not to fear. Don’t let a little techno mumbo jumbo about telescopes and telescope accessories stop you. Spectacular beauty is only as far away as the night sky in your own backyard.

Spotting scope magnification

2012-01-26T10:55:00.003-06:00

In terms of how much magnification you can use, effectively, in a spotting scope, your geographic location is a factor.

Out in the great wide-open spaces of the western U.S., the skies are not cloudy all day, according to the song, anyway. There’s an element of truth to that, because the climate is drier and, in many areas, the air is also thinner due to the elevation. Drier, thinner air makes for better images in spotting scopes and also more usable images at higher magnifications. There were birdwatching days when I had the magnification on my birding spotting scope pegged at 60x for hours at a time and I could have used even more magnification had the spotting scope been able to provide it.

When I moved back east to Chicago, where the elevation is much lower and the air thicker, not to mention much more humid, 60x on my spotting scopes almost never happened. Most days, 30x or 40x was about it before image quality began to fade, even though my little Kowa 663 had the optics do deliver great images all the way up to 60x.

I currently live in northern Wisconsin where I swear the humidity is even higher, on the average, than it was in the Chicago area. In two years, have yet to see a single day when 60x in one of my excellent spotting scopes could deliver great image quality.

I’m long overdue for a trip to my beloved great wide open spaces out west. Oh, give me a home where the buffalo roam ...

Northern lights Tuesday night

2012-01-25T09:48:00.002-06:00

We searched for the northern lights in our cold, partly cloudy, northern Wisconsin skies on Tuesday night, but the lights failed to make an appearance, despite the forecast for an auroral display. That’s the way it goes when searching for the northern lights, though. Sometimes you see the lights, sometimes you don’t, even when the odds are in your favor.

The aurora borealis (northern lights) are just one of the many ways you can enjoy astronomy without the use of astronomy binoculars or telescopes. Naturally, if you want to see all there is to see in amateur astronomy, you will need to setup & use a telescope or binoculars at some point, but there are astronomical events you can observe without looking in a telescope eyepiece.

I love meteor showers, for instance. These tend to be more predictable than auroras, at least as far as dates of occurrence, but showers are as just about as unpredictable as the northern lights when it comes to numbers of meteors seen. This, of course, makes them all the more delicious when you see a great one. I can also tell you from personal experience, that meteor showers can be a rather romantic experience if you share them with the right person, but I’ll let it go at that. ☺

Small spotting scope, please

2012-01-24T11:44:00.003-06:00

At the risk of revealing my age, I can tell you that there was a time in the spotting scope world when 60 mm spotting scopes were standard fare and the big 80 mm and larger spotting scopes had yet to hit the market. Most of us birders did just fine with those smaller spotting scopes, by the way, but once those 80 mm birding spotting scopes appeared, the rush was on to the larger scopes.

Bigger spotting scopes are still in vogue in the birdwatching world, but a lot of us who hit the birding trails and carry a spotting scope and tripod for hours at a time all have gone back to the smaller spotting scopes to save on weight and bulk. It’s a good plan if your jumbo wonder scope seems to be getting heavier with each passing year.

A smaller 60 or 65 mm class of excellent optical quality will truly do just about everything a serious birder will ask and will do it cheaper than the same model in a larger size. My old Kowa 663 with its excellent 20-60 zoom eyepiece, for instance has never failed me. I still have and use heavier spotting scopes when there is no need to carry them far, but when it comes time to hoof it down the trail, make mine a small spotting scope, please.

Pistol scope or iron sights?

2012-01-23T09:29:00.005-06:00

Bill and I have taken up target shooting as an activity and, even in the heart of a north woods winter, we manage to get to the shooting range when the weather allows. Shooting really is a terrific activity for a couple.

For me, shooting rifles and, especially handguns, is old hat. For Bill, this is all new, so I get to teach and he gets to buy the guns and all the gun accessories. Hey, we make a great team!

One of the first surprises I got as a teacher was just how hard it can be for a beginner like Bill to shoot iron sights. I’ve been shooting “iron” all my life, but Bill hasn’t, so I decided to mount red dot sights (scopes) on a couple of our favorite pistols and it has improved his shooting, considerably. Then, when I found a used 1x handgun scope at a local gun shop, I replaced one of the red dot scopes with it. No magnification, either way, which makes for an easy to steady rig and, of course, no front and rear sights to line up, either. I may trade the 1x scope out for one with magnification, later, such as Bushnell Elite 2-6x32, once Bill is ready to handle the magnification.

Still, I just can’t bring myself to go pistol scope or red dot scope on some of our pistols. One of the big reasons I love to shoot handguns and pistols, in the first place, is for their balance, point ability and lack of size and weight, but that all pretty much goes out the window when you add a scope to a pistol. Just isn’t the same gun, anymore, as far as I am concerned. I know you can put a red dot scope or pistol scope on almost any pistol, but, in my opinion, it seems almost criminal to do so on some pistols, such as our Ruger SR1911 in the pic, above. This Ruger (terrific gun, by the way) will stay just as is, thank-you very much.

Small telescopes in the winter

2012-01-20T10:18:00.004-06:00

I’ve always had a thing for going light and small on my equipment choices, whether it be cars, fishing tackle, binoculars, spotting scopes, digital cameras and, definitely, telescopes.

Make no mistake, I do own a wonderful, fairly large telescope and I love it. There are times when you need the optical muscle of large aperture telescopes to get the job done. Come spring, for instance, I’ll be hunting faint galaxies and for that pursuit, the bigger the telescope, the better.

Still, nothing beats small three or four-inch high-grade refractor telescopes for image quality, wide-angle views in the telescope eyepiece and, equally important, amazing portability and ease of use. I especially enjoy using my refractor telescopes in the winter months to “ooh” and “ah” over brilliant star clusters in Auriga, Gemini, Orion, Canis Major and Monoceris. That quick setup time for small telescopes is a huge plus when temperatures head down toward zero.

Speaking of the constellation Monoceris: if you own a small telescope, take a look at this constellation on a cold winter's night. It’s an unremarkable constellation to the naked eye since it has no bright and obvious stars, but it is a treasure trove of objects for a small telescope or astronomy binoculars.

Stay warm.

Telescope location

2012-01-19T11:05:00.003-06:00

Okay, when it comes time to setup & use a telescope in, say, your backyard, just where should you set it? The seemingly obvious answer in terms of a physical location is where you can see the biggest expanse of the sky, but that may not actually be the best location. Other factors come into play and you sometimes have to get a bit creative to deal with them.

If you are in the suburbs or the city, street lights and/or your neighbor’s yard lights can make or break you when selecting a place to observe with your astronomy binoculars or telescopes. Putting an object, any object, such as a tree, between you an offending light source can make a tremendous difference in how much you will be able to see. When there is no convenient object to block an annoying light, I’ve draped a towel over my head when looking through the telescope eyepiece. Your neighbors might give some odd looks when they see you doing this, so you may want to explain it to them. I know, because I used to drape a towel over my head as I sat outside my patio apartment when I was observing with the binoculars, often in my bathrobe, no less. I’m sure that was quite a sight to see.

One of the time-tested Telescope Observing Tips is to always setup your telescope from any radiating heat source, such as concrete, pavement, rocks and, yes, even buildings such as your house. These objects absorb heat by day and release it back into the atmosphere at night. This release of heat produces air currents that can degrade image quality in your telescope.

Unfortunately, a lot of us simply have to make-do with what we have for a telescope location. I’ve been known to use telescopes on a wooden deck, for instance, even though it puts me too close to the house and even though it limits the magnification I can effectively use, thanks to a deck surface picking up every footstep and jiggle you make.

Telescopes below zero

2012-01-18T10:25:00.003-06:00

We’re forecast to have clear skies, tonight, so I’ll no doubt grab the astronomy binoculars or, perhaps, one of my smaller telescopes and do a little astronomy. We’re also forecast to go well below zero, too, so emphasis on little as far as astronomy. I’m at an age where I have less resistance to the cold and it’s getting harder to put in long observing sessions with the binoculars or the telescope eyepiece in sub-zero cold.

Now, I’m sure that a lot of folks who aren’t astronomers are thinking this gal is off her rocker to setup & use a telescope in those kinds of temperatures, just to do a little astronomy. I even know some astronomers who would have second thoughts about that kind of cold. There is, however, a solid reason for braving the cold to get some time with the telescope or binoculars.

The air following a polar cold front tends to be clear and dry and that makes for excellent sky transparency and that, in turn, translates to more objects and more detail seen in the binoculars or telescopes. In fact, these cold, dry winter nights are often the best nights of the year for astronomy in our area. Moreover, even as little as ten or fifteen minutes with the telescope under a magnificent winter sky is enough to recharge my astronomy batteries to get through weeks of cloudy skies.

Now, where did I set those mittens?

Reflector telescopes collimation

2012-01-17T10:36:00.003-06:00

If you’re the type that likes to tinker, fiddle and otherwise fuss with gear, telescopes may disappoint you. There really is very little maintenance needed with telescopes or even telescope accessories, though some types of telescopes do require a bit more adjusting and upkeep than others. Still, all telescopes are simple to maintain.

That includes reflector telescopes, by the way. When it comes time to choose the right telescope, beginners sometimes avoid reflectors out of fear of having to adjust the mirrors (collimation). True, you do have to learn how to collimate a reflector if you want to get the most out of it, but I’ve never considered it enough of a chore to avoid reflector telescopes.

True, there was a day when collimation could be a time-consuming undertaking, but laser collimators have changed that and thankfully so in my case. I have to wheel my large Dobsonian telescope (a type of reflector telescope) around the yard as needed to view areas of the sky I want to see ( yes, it is actually equipped with wheels for the sake of transport). It’s a sometimes bumpy ride, though, and just enough to throw alignment off a bit, so I typically collimate the mirrors at the start of every observing session. In truth, the mirrors are never way out of alignment, even using the telescope this way, but the mirrors are optically superb, so why not have them aligned, perfectly?

How long does collimation take when I use a laser collimator? On the average, not much longer than it takes me to change a telescope eyepiece. Doing an initial collimation with a new telescope does take longer, but once you’re in the ball park and assuming you haven’t been rough on the telescope, collimation is no big deal.

Clear nights for the telescopes

2012-01-16T10:54:00.002-06:00

“…. and the skies are not cloudy all day.”

Okay, I don’t know where the heck that is, but I know for sure it isn’t in northern Wisconsin in the winter. If you love to setup & use a telescope and do astronomy as much as I do, clear nights are like gold in this part of the country. In fact, clear winter nights can be so elusive in our area as to make some folks think twice about spending money on telescopes and telescope accessories.

For better or worse, I am not one of those folks. I love astronomy too much to give up because of cloudy nights. Okay, I’m definitely one of those glass is half full types when it comes to astronomy, but when the skies do clear in our north woods at night and you do get a chance to use your astronomy binoculars or telescopes, it is worth putting up with a lot of cloudy nights. The images we get in the telescope eyepiece when the sky finally clears will take your breath, away.

Sure, we could have retired to the desert in Arizona to get more in the way of clear nights, but no way would I be able to ski right out my back door after a fresh snow in that country. Nope, I’ll stay right here, thank you, but if you astronomers in Arizona could send a few clear nights our way, I would be grateful.

New planets

2012-01-13T11:23:00.003-06:00

When I started doing astronomy some forty plus years, ago, there were only nine known planets to science (Pluto was still considered a full-fledged planet at that time). One of the big arguments in astronomy at the time was whether planets around other stars were common or whether they were rare. Was our solar system with its planets the exception or the rule in the universe?

In those days, I asked myself that same question just about every time I looked through my astronomy binoculars or peered through a telescope eyepiece. My gut instinct told me that every star had to have planets, but gut instincts do not constitute scientific evidence. Hopefully, this question would be answered in my lifetime.

It has. Today, thanks to all the advances in astronomy and, especially, thanks to space satellites such as Kepler Space Telescope, the number of stars now showing evidence of orbiting planets is in the thousands and the number seems to grow with each passing week. Looks like my gut instinct was right, after all. That's great, but no telescope, at least no telescope that I will ever own, will see planets around other stars. Still, when it comes time to setup & use a telescope, it is nice to know that I may actually be looking at other planets, even if I can't see them. Of all the telescope accessories I possess, my imagination is truly the one I value the most.

Finder scopes for telescopes, part two

2012-01-11T13:25:00.004-06:00

Yesterday, I wrote about the advantages and disadvantages of red dot finder scopes for telescopes. They're one of the easiest to use telescope accessories you can fit on a telescope, no doubt about it. Today, let’s take at the more traditional optical finder scopes that offer magnification.

First, let’s dismiss the typical 6x30 finder scope that comes with some beginner’s telescopes as a useable option. I’d rather see just about any red dot finder scope on a beginner’s telescope than a 6x30. A big part of the problem, here, is the poor optical quality of these small finder scopes. These 6x30s packaged with starter telescopes tend to be dark and blurry, not to mention being poorly constructed. Even if you could find a quality 6x30, a 30 mm objective is still a woefully small objective to observe the night sky. A much better choice is to step up to a 7x50 or 10x50 finder scope to improve resolution. Okay, now that we have a good 50 mm finder scope with some magnification what are the pros and cons of traditional optical finder scopes?

The big advantage of optical finder scopes over red dot finder scopes when it comes time to setup & use a telescope is the more precise aiming that an optical finder scope allows. With optical finders, you will see far more stars than are visible in a red dot scope. Since these finder scopes are typically equipped with a crosshair, you can very precisely center your telescope as needed, either on the object you want to see, assuming it is visible in the finder scope or on a nearby star, as indicated by your star map, if it is not. Obviously, this kind of precision is not needed for easy to locate objects, but when searching for challenge objects, nothing beats a good optical finder scope. The trick is to find one that offers views similar to your favorite star map. Other very helpful features are an illuminated crosshair and a right angle eyepiece for more comfortable viewing.

You do, however, pay a price for this more precise aiming. For one, optical finder scopes require you to “belly up” to the finder scope, so to speak, in that you must place your eye right on the eyepiece of the finder scope, just as you do on the telescope eyepiece. (With red dots, you can stay as far back as is comfortable.) This can be a real neck-breaker, depending on the position in the sky of the object you want to see. For another, there is a disconnect between what you see without the finder scope and what you see when you look in the finder scope. If you are looking at an area of the sky with stars of fairly similar magnitudes or in area of the sky with very few stars visible, which star is which when you look in the finder scope? It can be quite a puzzle. Finally, if your finder scope offers upside down images or reversed right to left images, you have to reconcile that with your star map. Things can get confusing in a hurry. Bottom line: it takes some experience to learn how to use a finder scope to its full potential.

So which type of finder scope do I use on my large Dobsonian telescope when hunting for the most difficult to locate objects? Actually, I use both, as you can see in the picture. Immediately to the left of the focuser (far right), I have a Telrad red dot scope and to its left, I have a 10x50 finder scope with illuminated crosshair. The red dot allows me to point the scope very quickly in the general neighborhood of the object I am hunting and then the 10x50 takes over as needed. That’s a lot of finder scope power on one telescope, but the only thing more efficient for finding objects would be a computer on the telescope. Call me an old fuddy-duddy, but I am not quite ready to take that step.

Finder scopes for telescopes, part one, red dots

2012-01-11T11:09:00.004-06:00

One of the questions I am asked by folks who are trying to choose the right telescope concerns the finder scope. A finder scope is, after all, one of those telescope accessories you will be using, constantly. Which is better, a red dot finder scope or a traditional finder scope that offers a magnified image, assuming both are properly adjusted and pointing where the telescope is pointing? Answer: both types of scopes offer advantages as well as some disadvantages. Let’s start with red dots.

Red dots are definitely the easiest to use. Just put that red dot on the object you see in the sky and then look in your telescope eyepiece and the object is there. That’s great if the object you want to see is visible to the naked eye, such as the moon or planets or some of the brightest deep-sky objects. What about objects that are not visible to the unaided eye? The red dot still works well if the object is close to a bright star that can be seen with the naked eye. Just put the red dot on the star and then center the star in the telescope eyepiece and hop over to the object by moving the telescope in the right direction as needed.

Unfortunately, there are plenty of objects you’ll want to see that are not conveniently located near a bright star. You then have to point the red dot in a by-guess-and-by golly way to where you think the object is in the sky. If the object is small and requires the use of a high magnification eyepiece to detect, it’s like looking for a needle in a haystack because of the very narrow field of view produced by using high magnifications. You’ll need a lot of patience if all you have is a red dot finder scope for these objects.

The good news for someone new to using telescopes is that the things you’ll most want to see – the moon, the planets and many of the famous deep-sky objects are easily found using a red dot finder scope.

We’ll look at the more traditional optical magnification finder scope another time.

About the picture: my favorite red dot finder scope and arguably the finest quality red dot scope made, an older model of the Telvue Starbeam.

Telescope diagonals

2012-01-10T10:48:00.003-06:00

Okay, let’s discuss one of the most overlooked telescope accessories, namely, the diagonal used on refractor telescopes and most catadioptric telescopes.

As a rule, the quality of the 90-degree star diagonal supplied with a given telescope is commensurate with the quality and price of the telescope you buy. Cheap telescopes have cheap diagonals; premium telescopes are typically supplied with premium quality diagonals. This makes sense on both ends. Cheap diagonals help to keep the price down on low cost telescopes; premium grade diagonals bring out the best in premium telescopes. A manufacturer would be foolhardy to supply a cheap diagonal on their best telescopes – you don’t try to save a few bucks when putting your best foot, forward.

Do excellent quality diagonals make a difference, though? Yes, they do. Unknown to most users of cheap telescopes is the fact that poor performance is often due, in part, to a poor quality diagonal. First, there is the matter of the mirror. The mirror used in a diagonal must be as optically close to perfectly flat as can be. Otherwise, the mirror introduces aberrations into the optical system. Second, the mirror must be properly aligned and centered in the diagonal body. Otherwise, the mirror, once again, introduces more optical problems into the optical system. (This is actually a common problem on cheap diagonals.) Lastly, the mirror used in a diagonal should have the best mirror coatings. Otherwise, you will lose some light transmission at the telescope eyepiece.

All this is well and good, but can you actually see, with your eyes, the difference between a poor diagonal and a quality diagonal? Absolutely. The difference can be quite pronounced, especially if you have been using a poor diagonal. The problem is that many astronomers don’t have a handful of diagonals on hand to test and they may not be aware of how their diagonal is affecting performance.

Good diagonals, though, like any other quality telescope accessory, do not come cheap. Price, as always, is a fairly good indicator of what you get with a diagonal.

Pictured: Stellarvue makes a high grade diagonal at a very reasonable price.