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So you want to view the Eclipse…

On August 21st, 2017 a large portion of the Continental US will experience a total solar eclipse. Much of the rest of the continental US will experience at at least a partial eclipse: Philadelphia will have about 78% totality, NYC 75%, Washington DC 84%, Chicacgo 88%, Los Angeles 70%, Seattle 93%, etc.


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.



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:


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!”


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 hope 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 has 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


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:


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.


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:


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.



Telescope Tips: Dark Skies – The Philadelphia Region

When selling a telescope to a customer, we often give advice on how to view in light polluted areas. Simple stuff such as selecting your targets, using filters, etc. Often we asked “is there anywhere I can go and get away from the light pollution?”

The answer depends on your answer to ‘How far do you want to drive?’

One thing we have in our telescope section is a version of this light pollution map on the wall:



Happy Thanksgiving from Spectrum Scientifics!

Today is Thanksgiving, and we are closed! We will open tomorrow at 10AM and will have extended holiday hours on Friday and Saturday until 9PM! Come and get some evening shopping in Manayunk!

NASA creates an earworm.

OK, I admit I am not the most astute and trendy person. When the overwhelming internet meme ‘Gangnam-Style’ hit the web I managed to avoid seeing much of it. But it was not completely avoidable – it seems that the music inspired a huge number of parodies, imitations, and outright spammers (check out how many youtube videos claim to be ‘Gangnam-style’ while at the same time having posting dates from 2-3 years ago…yeah….)

But now jumping in the fun is of all groups: NASA. They have made this video “NASA Johnson Style”. I guess Cape Canaveral Style didn’t fit as well. It is awesome and fun:



Spectrum Scientifics Microscope Buyer’s Guide – Repost

The holidays have us pretty busy, so here is our Microscope Buyer’s guide for those seeking to buy one!


Spectrum Scientifics Microscope Buyers Guide

Congratulations! You’ve decided to buy a microscope! A microscope is a wonderful instrument that can fascinate kids and adults alike. With proper care, a microscope can last a lifetime. But buying a microscope can be confusing for the first time buyer. There are so many different designs, it can be a bit overwhelming. This guide should help you make the proper choice in deciding on a microscope model.

First let’s start by discussing the different designs of microscope. We will break microscopes into three different categories: Compound Microscopes , Inspection/Dissection Microscopes, and ‘Other’. We’ll cover these one by one.

Compound/Biological Microscopes : Compound (or Biological) microscopes are the models designed to be used with slides. They are high powered; using multiple objective lenses (the lenses that point at the slide) to typically provide 40X, 100X, 400X and sometimes 1000X right off the shelf. Modern compound microscopes usually have some sort of illumination from below to light up the slide. Depending on the design of the compound microscope it may have features like binocular eyepieces (two eyepieces, but do not provide stereo vision) a mechanical stage for moving the slide easily, coarse and fine focus (for easy focusing) and different lighting designs.

The disadvantage of a compound microscope is that you pretty much must use it with slides. You can’t just plop a bug, coin, or plant leaf onto the microscope and expect to get a decent image. Compounds aren’t designed to do that. You can cut up the leaf/bug/whatever and make it into a slide with some effort and a slide-making kit, but that does take some time and only lets you view s small part of the the found object.

Inspection/Dissection Microscopes: Inspection/Dissection microscopes are designed to be used with any object you can fit on the microscope’s staging area. This can be coins, stamps, bugs, plant parts, circuit boards, small animals, or whatever else you might find. Inspection Microscopes often have much lower magnification (10x-40x is typical), much wider viewing fields, and very often the binocular versions give true stereo vision. This allows the viewer to ‘work’ (I.e. dissect) on the object being viewed and get a true sense of depth of objects like coins. Inspection Microscopes may have only 1-2 levels of magnification verses the 3-4 on compound microscopes. The microscope will also have top-down lighting, and some may have bottom-up lighting as well. The eyepieces used in many mid-range inspection microscopes are often larger and more comfortable to use.

The disadvantage of a compound microscope is that its magnification is very low and you cannot use it with slides. That means if you want to see cells, bacteria, or other very tiny objects you will need to get a compound microscope as well.

As you can tell from these write-ups, these two designs are very different from each other. Before we discuss the third category, let’s compare and contrast these two designs:

Features: Compound Microscopes vs. Inspection/Dissection Microscopes

Compound Inspection/Dissection
Magnification High: 40x and up Low: 10-40x typical
Levels of Magnification 3, sometimes 4 (40x, 100x 400x typical) 1 or 2*
Lighting From Bottom From top (or top and bottom)
Viewing Monocular or Binocular, but not true stereo Stereo Binocular
Viewable Objects Slides Coins, stamps, bugs, plants, circuit boards, etc.
Extra Features (depends on model) Mechanical Stage, Coarse & Fine Focus, Bottom light
    *Some models of Inspection Microscope have a continuous zoom from 10x to 30 or 40x

This chart should give you some idea of the basic comparison.

We haven’t forgotten about the third category of microscope: Other. This category covers some odd designs that work as specialty instruments. Some examples of Other microscopes would be:

Hand-Held Microscope: These are small, pocket-sized microscopes used in a fashion similar to Inspection/Dissection microscopes. They may have higher magnification than Inspection microscopes (30-100x power), often have a built in light, and are light and portable. Their main disadvantage is they have a limited viewing field- you must put the scope directly on the object being viewed. Their optics & lighting are also rarely up to the quality of full-sized microscopes, and moving to find a specific part of an object can be tricky. Still they are great in the field where a full-size microscope would be unwieldy.

Digital Microscopes: Many traditional microscopes can have a digital camera built into their structure, or can have their eyepiece replaced with a digital camera. But some microscopes are designed from the ground up to be used as high-power digital microscopes. These items have no eyepiece, only a CCD camera and an objective lens. They may have fixed or variable magnification, and the computer screen resolution will vary from model to model. Many ‘toy’-like designs have VGA quality graphics, which is 480 x 640. This level of quality is acceptable for kid’s use but is not sufficiently detail for any real work or study. Usually 1.3 Megapixels is the highest quality available for devoted consumer digital microscopes. If you desire higher resolution a compound microscope with a digital microscope eyepiece might be in order.

High Power Magnifiers: A hand-held magnifier is a very different instrument from a microscope, seeing as how most magnifiers have about 2-3x magnification and microscopes can go as high as 1000x. But some close work magnifiers have very high power (10x and up) and the line between a microscope and a magnifier starts to get blurred. As far as optical design goes, they are still very different animals: The magnifier has just one lens (or set of cemented lenses) while the microscope has both an objective and eyepiece lens. Although the difference is there, the jobs they cover get blurred. If you need a lower powered microscope or a high power magnifier, make certain you are choosing the correct tool for your viewing needs.

Hybrid Microscopes: Given the difference in use between a compound and an inspection microscope it didn’t take to long for some folks to come up with a design that tries to do the job of both microscopes. Usually this is done by taking a compound microscope design and adding a top-down light to the system. These designs can be a great boon to parents or buyers who cannot decide which usage they would prefer. The disadvantage is that like many other things that try to do multiple jobs, they are not the best at either job. Most often hybrid microscopes are better at being a compound microscope than an inspection microscope (mostly due to the higher powers of a compound microscope), but at least the option for using the microscope both ways is available. Consider a hybrid if you can’t decide between designs, but remember it won’t do the job as well as a devoted microscope.

Toy Microscopes: Many ‘toy’ microscopes are available on the market, usually they are either plastic hand-held models or plastic versions of compound designs. The former can be great fun for small children who would like to have something to view nature close-up but can still handle their not-always-delicate hands. The latter, however, is usually to be avoided. Cheap plastic bodies and cheap plastic lenses will give the viewer a very poor experience indeed. Companies that make these items often pile on junk accessories like plastic ‘viewers’, poor slide making accessories, and other gimmicks to cover the fact that the instrument is junk. Avoid these if at all possible.


So now that we’ve discussed the various microscope designs, we should talk about that are features of microscopes:

DIN Objectives: DIN stands for Deutsches Institut für Normung – Don’t worry about that. Just understand that DIN eyepieces are set to a higher standard the the average beginner microscope. DIN objectives are generally universal so you can take one DIN objective out of one microscope and thread it into another. DIN eyepieces are often a bit more costly.

Digital Microscope Eyepieces: Digital eyepieces can be a great boon to your viewing experience. When plugged into a computer they can be used to view objects on a much larger screen, and the images can be saved, modified, emailed, etc. Some digital eyepieces can make movies as well. Some microscopes have digital eyepieces built into the body of the microscope, but almost all non-toy microscopes can have their eyepiece’s removed and replaced with a digital microscope eyepiece. The image quality from a digital microscope eyepiece can go from VGA (or even TV) quality all the way up to 5.0 Megapixels or even more.


One nice feature about microscopes is that they don’t need a whole lot of accessories to get a good experience. But there are a few things you can get to increase your viewing experience:

Prepared Slides: Professionally made slides are always excellent to have around. They let you see objects with a quality that few can match. They also may be of specimens that may be very hard to obtain. Consider having a few prepared slides to enjoy.

Slide Making Kits: Sooner or later you will want to make your own slides. This will involve blank slides, coverslips, a razor (for cutting samples) and some mounting medium. These can be bought individually, but it is often more economical and convenient to buy a kit.

Special Slides: Blank slides with concave dips can be obtained for holding liquid samples. This is excellent for examining microscopic life in pond water and other sources.

Slide Boxes: Once you make your own slides you should store them properly in a slide box. Don’t leave them to get dust and scratches.

Microtome: If you make a lot of slides, cutting thin sample sections with a razor can get annoying after a while. A microtome can help. It is a mechanical device that helps cut a thin sliver off the sample. Think of them as working like the meat slicer at your deli only on a much smaller scale. Microtomes can be hand driven devices for around $75 to fancy automated item costing hundreds or even thousands of dollars.


As mentioned above, before you decide on what model microscope you want, make sure you know what it is you want to do with it! Fun can be had viewing both prepared slides and making your own slides using a compound microscope. But it can also be a real thrill to take objects straight from the backyard, or even from your pockets and put them under an Inspection/Dissection microscope. If you have needs beyond having fun observing (research, coin collecting, etc), make certain that your microscope does that sort of job first and foremost.

Happy viewing!