What's new here?

Archive for the ‘Telescope Tips!’ Category

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.

(more…)

The Long Life and Sudden Death of the Edmund Astroscan Telescope

Few telescopes in this world are as….distinct as the Edmund Astroscan, I mean, _look_ at it:

astroscan

The Astroscan may hold a record for the longest running mass-produced telescope on the market, possibly only beat out by some of the classic Cassegrain models. It is also was one of the most controversial telescopes made (at least that wasn’t an outright scam or waste of people’s money). A simple search for the Astroscan in Astronomy forums reveals that the little red telescope has many detractors, and many defenders:

“I’ve never seen one that was in collimation”

“I love it! It is so easy to use!”

“Its an old design that should have been put to rest a long time ago, there are much better models in that size and price range!”

etc…

The back and forth actually reminds me more than a little bit of of the old Mac vs. PC wars on newsgroups, where PC advocates objected to people buying things that might not have been as  powerful or economic as what they used and Mac advocates vehemently defended their choices with rabidity and dared to be a fraction of the marketplace. Of course, in this case the scale was much smaller.

So what was the story behind this little telescope? Why was it so different than other telescopes? What happened to it? Why was it so loathed and loved? I shall try to answer these questions with my limited experience of having worked for Edmund Scientific for the last couple of years that the Edmund family owned the Scientifics division (The Edmund family still owns the Industrial Optics portion of the company).

In The Beginning

In 1976 the Edmund Scientific company started developing a telescope that would be its flagship model. The idea was to make something that was easy to use, easy to transport, and wouldn’t look out of place in a 1970’s Living Room. Given that in that era almost all commerically sold telescopes were tripod mounted things that took up a lot of real estate when set-up this was bit of a sea change. The optical system was developed so that the customer would not have to do any maintenance (or collimation) that reflectors often required. It was also designed with an optical window so that dust and other debris entering the tube would be minimized. The body was developed out of ABS plastic to be as durable as possible, and was smooth enough so that it would ‘roll’ on its base without being so slippery as to move with a hard breath.

Some decisions were made for its contruction. It initially did not have any aiming mechanism as it being a rich field telescope was assumed to be good enough to along (it wasn’t). The problem was mostly aesthetics: Any aiming mechanism would spoil the clean lines fo the Astroscan’s body. Eventually a sheet metal aiming deveice was developed that helped. Later models, as shown in the above picture, had a red-dot finder added for aiming.

The Astroscan was aimied squarely at novice users and this was both a help and hinderance. Hardcore amnatuer astronomers were grumpy that so much effort was put into a telescope that wasn’t aimed at their needs, and didn’t address what they felt was ideal in a beginner telescope. The validity of their arguments continues to be debated to this day.

A harder barrier for the Astroscan to overcome was its low-power. Being a rich field telescope with only 1 eyepiece included it had what seemed like an anemic 16x magnification. This was in an age where retail department store telescopes were sick with ludicrious claims of unattainable magnification (640x!!!!). Edmund had hoped to have their new telescope sold by wholesale as well as through their famous catalog, and seeing this stylish but-low-powered telescope next to the fake claims of cheaper telescopes was a hinderance to those long-term wholesale plans.

Other features of the Astroscan were controversial: To reduce costs the focuser used a rubber wheel (as opposed to a rack and pinion system) that would press against the eyepiece’s base and move when the focuser knob was turned. But this wheel would develop ‘flats’ that made for a bumpy focusing experience, and in very cold weather it could shrink and not ‘grab’ the eyepiece properly. That said, some people loved it, including the founder of Orion Telescopes, Tim Geisler.

Other features of the Astroscan would be introduced later, mostly as accessories: A threadable solar projection system, a moon hook that would allow the Astroscan to be mounted to classic Equatorial mounts, a camera-style tripod that was designed especially to allow the Astroscan’s base to thread onto it, an image inverter, and a few more items were developed.

The Astroscan did well as telescopes sales go. The exact numbers are unclear but in its lifetime it is assumed to have sold around 90,000 units, making for around 2400 units per year, which is good numbers for a company that does not exclusivelty sell telescopes.

The Mid Life Crisises-es-es

The Astroscan had been planned on being sold below $100.00 and much of the developement issues were based on that cost limit. But this was to cause a few growing pains for the Astroscan. For one, the 70’s were an era of major inflationary pressures and keeping costs down just was not possible. At some point in the 80’s a decision was made to move production to the less expensive Japan. Production began in that nation after many, many, many long meetings and trips by the senior brass from Edmund.

Japan’s production, like most things in the Astroscan’s history, was polarizing. Some considered the Astroscans of that era to the worst ones ever made (even calling them ‘Astroscams’) while others declared Japan’s attention to optical details produced some of the best models made. In any case, production costs in Japan rose steadily over the years to the point where, when combined with the overseas shipping costs, it was no longer economical to produce the Astroscan in Japan. Production was returned to Barrington, NJ in the USA.

By this time, the Astroscan had quite a number of years since its development and was starting to look a little long in the tooth. It hadn’t had much attention paid to its design in years (the last major changes happened when the production was moved to Japan). There were other issues:  The Astroscan screamed 70’s design, but not loudly enough to provoke nostalgia. It’s cost had also risen to over $350 Much higher than optically similar models), the product copy hadn’t even been rewritten in what seemed liked decades (dated-sounding references to ‘Space-Age design’ were still present as of the 1999 catalog).

Other issues were a problem. Edmund had introduced a series of lower-cost beginner telescopes to work as a fleet with the Astroscan as the Flagship, but none of them garnered much success. The wholesale program became a morass as other retailers undercut Edmund’s pricing, or even broke up the telescope into its component parts and sold them individually to get around any Minimum Advertised Price policy Edmund might introduce. The wholesale program also did not account for retail inventory needs, so telescopes were often shipped out to other retailers when Edmund’s own retail telescope sale needs were not fulfilled.

Even worse, the patent on the design was due to run out in 2000 and a slew of imitators came in. The most visible of which was the Bushnell Voyager

voyager

The Voyager was not as sturdy as the Astrscan, having a coated styrofoam body instead of ABS, but it had a cost of $199 vs the Astroscan’s $360. Other imitators soon popped up, such as the Orion Funscope:

funscope

Other, ‘interesting’ Astroscan imitators appear courtesy of Edmund’s Chinese agents. The most internally infamous of which was a model (one never developed for the consumer) which was just straight optical tube shoved into a painted metal ball. It was immensely heavy compared to a traditional astroscan and had just a piece of colored tape to cover the seam between to the tube and the ball. The telescope famously used the rack end of a zip-tie for its focuser rack. Oddly enough the optics in the telescope were not bad!

Still, it seemed like something needed to be done:

The New Astroscan that never was.

In 2000, plans and committees were set up at Edmund to help revitalize the aging Astroscan. Message boards were inquired, costs assessed, ideas explored, et cetera. Among those plans it was decided to do an ‘almost-overhaul’ of the Astroscan. The optics would be changed to more modern and less costly counterparts. A mechanical engineer was sourced to develop and improve the focuser. Sourcing parts from Asia was explored to reduce cost while still keeping the production in the USA. Eyepiece changes were considered and it even variations on the body color (a star pattern on black was considered, not uncommon today but radical for the time) were considered, as well as a possible oversized (6″ mirror) version! The overall plan was to get the Astroscan competitive in the new playing field, to answer as many of its criticisms as we possibly could, and overall revitalize what had become a dusty corner of the world’s telescope offerings. How much would the new Astroscan differ from the old one? We’ll never know.

In 2001 it was announced that Science Kit & Boreal Lab would purchase the Edmund Scientific. All work on the New Astroscan Project ceased. Edmund continued to produce the Astroscan for SK&BL while they consolidated the move to their facility, but eventually they set up production of the Astroscan in China. The quality was a bit more concerning and the classic RKE eyepieces were replaced with generic Plossl eyepieces (partly because the Edmund family still claimed the rights to the RKE eyepieces and sold them in their Industrial Catalog for years afterwards).

Under SK&BL or one of the other administrating companies the Astroscan continued to be sold until 2013, when disaster struck.

What’s in a Mold?

Its not clear what happened, but somewhere someone dropped something shouldn’t have, or something wore out, or …well anything. The mold used to produce the Astroscan body broke. That is all we know at this point. It could have been wear & tear, having been used to produce at least 90,000 telescope bodies.

Molds are costly, and while developing a new model could have been done it would have required new machining, new engineer work, and a host of other aspects. ScientificsOnline decided to not produce a new mold. Instead they introduced the Astroscan Millenium, a mini Dobsonian with similar optical characterisics.

astroscanmill

Oddly enough, this ‘new’ design solved all the issues that critics had complained about with the Astroscan: it had different eyepieces, you could now collimate it, etc. Of course it lost its classic design and character in the process, and if that design looks a bit familiar it is because other companies have been producing for over a decade:

009

It essentially a red version of the Orion Starblast Mini-Dob. The irony here is that the StarBlast was designed to match the optical features of the Astroscan. Welcome to your closed circle.

The Aftermath

Although not as rage-inducing as the PC/Mac wars, there definitely was an element of form vs function with the Astroscan. Yes, they did go out of collimation despite the claims, and it was very hard to get them back. That said, I have seen ones bought in 2nd hand stores on the cheap that were perfectly collimated – everything else was messed up, however.

The simple fact is that Edmund Scientific was not really poised to become a full manufacturer of telescopes like Meade, Celestron, or Orion. They had a great contender with the Astroscan, but all of their other models were not as able to support their costs of development. While some of the telescopes  Edmund made in the 60’s were classics, they would not be able to compete in the modern market.  Edmund did not develop an import line of telescopes the way other major telescope brands did. This is not a surprise as the Edmund company found there was more money to be made developing industrial optics than there was in the telescope market.

The Spirit of the Astroscan is not gone forever, either, Astronomer Norm Sperling, who actually worked on the original Astroscan design ran a Kickstarter Program to develop an Astroscan inspired telescope.  In fact, it is essentially the Astroscan made by more modern methods and suppliers. The kickstarter has ended, however, and it is unknown if production will continue.

www.spectrum-scientifics.com

 

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’.

3111

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:

(more…)

Telescope Tips: Finder Scopes vs. Red Dot (Reflex) Finders

Aiming a telescope is tricky: It sees only a tiny portion of the sky, it might not be in focus for what you are looking at, and slight bumps can throw off your aim. That is why most telescopes come equipped with some kind of aiming device to help you find objects in the night sky. In the past this was almost exclusively with a Finder Scope – a little, low poweder telescope on top of the main telescope’s optical tube with a cross-hair that was used to aim.

FINDER SCOPES

The design of these little telescopes would vary from 20mm to 50mm in diameter, and the power was from 5x to 9x, typically. The holding bracket originally

083

would be two metal O-Rings with three thumbscrews each to adjust the aim of the finder scope. More recently that design would be replaced with a single ring with two thumbscrews and a spring bracket. Those were the good ones, anyway. Cheaper telescopes would often have a plastic 5x finder scope with a single holding bracket with

Not a good sign.

Not a good sign.

three plastic thumbscrews that would often frustrate new telescope owners as this mount is clunk and hard to control and the optics in the finder scope were poor.

This frustration would lead to a buig change in smaller telescopes around 10-15 years ago as they switched from cheap finder scopes to using reflex finders.

 

REFLEX FINDERS

Reflex finders, or red dot finders involve no magnifying optics. Instead the reflect finder has a window that you look through and a red dot is projected to show where the telescope is aimed. Adjustment is made by two knobs. This was much easier to deal with fot new astronomers as the main frustrations with cheap f

080inder scopes were mostly alleviated by using a red dot finder. But unfortunately they were replaced with new issues. The first being that all too often the new astronomer would leave the Red Dot Finder on after the viewing session was over, which would drain the battery. Long term storage would also be an issue as many would forget to remove the battery and they might leak acid onto the electronics.

The final issue was that once the astronomer gains some experience they will not be able to use the Red Dot Finder for a technique that is ued by more advanced astronomers to find objects: Star Hopping. This is where the viewer jumps from star to star in the field-of-view of the finder scope to get towards an object they are seeking such as a small nebula or globular cluster.  The technique involves having one bright known star that is near another known star (not as bright) such that they can both be in the field of view of the finder scope. That 2nd start is then centered in the finder scope and a 3rd star that is near the edge of the field of view is found and so on. It is a tricky technique to learn and unfortunately you can’t do it with a Red Dot Finder.

SO which to choose? Well, some do not:

Why_not_both-

More determined astronomers will actually have both designs on their telescope. A red dot finder to easy aiming along with a larger finder scope for close work and star hopping. This may not be an option for those using smaller telescopes as they have limited space for such extravengance.

Here is a summary of the main points along with some other advntages and disadvantages:

FINDER SCOPES:

Advantages:

  • Have actual magnification
  • Can be used to star hop
  • Magnification gives a  better sense of where you are viewing
  • Can be purchased as ‘right angle’ which makes using them on Reflecting telescopes easier

Disadvantages:

  • Harder to use for new astronomers
  • Trickier to align properly with the optical tube
  • Cheap ones extremely hard to aim
  • Need to keep clean

RED DOT FINDERS

Advantages:

  • Easy to use, especailly for new astronomers
  • Much easier to align with the telescope

Disadvantages

  • Batteries can be drained if you forget to swithc off
  • Batteries can leak in long term storage
  • No magnification means no star hopping

Have fun viewing whichever you use!

www.spectrum-scientifics.com

Assembling the Orion StarSeeker IV 130 GoTo Reflector Telescope

We’ve recently added the Orion StarSeeker IV 130 GoTo telescope to our offerings and since we needed a floor model to show customers we thoguht it would be nice to show the assembly of this telescope. Let’s look at how it appears once assembled first:

6069a

(more…)

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