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Archive for February, 2011

The Lies Magnifier Manufacturers Tell…

Every now and then we get a customer in the store who wants a very high power magnifier. Sometimes they bring printouts from other retailers that show some rather….unlikely high -power magnifiers with powers of 20x, 30x, even 50x. We unfortunately must inform them of the truth of these claims. The fact is – what is printed in the copy or actually on the magnifier is not true.

Oh, its not really the other companies fault – they are just going with what they see on the box and on the product. A typical example is this magnifier:

An Example of a mis-listed magnifier

Don’t you believe it!

You’ll note this has a rather generous 30x magnification, which still having a nice, wide 21mm lens width.

Nonsense! The rules of optics are remarkably clear on this – the simple fact of the matter is that the more powerful a magnifier is (the higher its magnification) the short its focal length (the point where light rays passing through the lens meet on the other side of the lens) must be! And the shorter that focal length, the smaller the magnifying lens will be.

Let us elaborate:

A large handheld magnifier that probably everyone has in their drawer only provides about 2-3x and so has a long focal length of about 10″. Focal length equates to something known as ‘working distance’. What this means that you can use the magnifier about 10″ away from the thing you are viewing (this will vary slightly).

However, as you increase the magnification of the lens, the focal length of the lens must be made shorter – this also means the diameter of the lens must also shrink or else your lens will become excessively thick and will have a distorting shape – think of looking through a crystal ball and how messed up that image is. Its a good example of a wide diameter lens with a very small focal length (a ball lens, ineffect).

What this means is that by the time you get to just 10x magnification, your lens is barely over a 1/2″ in diameter. This triplet lens we sell is a good example:


The diameter is just 18mm on this unit, and in order to avoid image distortion the lens is a triplet design – where three lenses are placed together to make a much better image than one lens alone would provide. As you can see, the higher power we go, the smaller the lens is going to get. In reality, our 30x lens shown up top should really be about 4-5mm in diameter. Not a very big lens at all.

Truth to be told, barring some optical tricks (which I can assure these ’30X’ magnifiers do not employ) most magnifiers rarely go above 12-15x in power. That realm is reserved for low powered microscopes, which are a different optical beast altogether.

Unfortunately, big numbers sell, and so manufacturers keep putting unrealistic figures on their products knowing that most people won’t know any better. The real tragedy is that most of these overplayed magnifiers are not bad products! The 30X magnifier shown above is actually a decent 7-8X loupe magnifier. We’re even guilty at Spectrum of carrying a few of these ourselves – but in our product copy we note that the listed magnification is probably not accurate. We wish we didn’t have to do that, but we don’t like lying about a magnifier’s true abilities, we don’t like discarding a decent product, and our complaints to the manufacturer have fallen on deaf ears.

So remember these words when you are looking for a high-power magnifier. Don’t get suckered in by inflated claims and be realistic about what your lens can do!

Want to buy magnifiers?


Robotime Walking Robot Dinosaur Skeletons!

We’ve seen plenty of wood dinosaur skeleton puzzles but this one is a new twist: They are robotic skeletons and they roar and walk!

You put it together out of 70-85 pieces (depending on the model) and in addition to the skeleton there are also motors and battery pack (using 3 AAA batteries) that make the dinosaur roar, walk (in a shuffle) and in the case of the T-Rex, swing his tail! The neat part is that the robot is sound activated! Clap your hands and it will start walking and roaring!

T-Rex is not the only member of this line. There are also the Stegosaurus, and the Tricerotops:

Triceratops Robotime Dinosaur


We (finally) got some meteorites at Spectrum Scientifics! These small meteorite samples hail from the Campo Del Cielo. This is a site where a substantial meteor struck back in 2,200 BC leaving  a crater field some 2 miles wide, 12 miles long and with 26 different craters. The field was reported in 1576, but was then ignored for a couple of centuries when it was rediscovered and lead to study and collection of the meteorite pieces.

Now some of those pieces have made their way to us. These are not tektites, these are genuine meteorites! Or at least pieces of them.

The smallest meteorites we sell are a pair of 1.5g meteorites in a small box.

For a ‘closer’ feel we also have a meteorite pendant: a 5-6g meteorite pendant with cord necklace.

Finally we have the actual meteorite pieces. These are boxes pieces, packed simply and easily removed from their display frontage.  They come in three different sizes: 10 grams, 25 grams, and 40 grams.

These meteorites are 93% iron, 6 % Nickel, 0.5% Cobalt and a small number of trace elements. Get some to add to your space or mineral collection!


Just a little video while we are out!

We’re out of town today, attending the New York Toy Fair so we’ll just leave you with a quick video of out Solar Energy Kit in action:

Floating Planets! Look Ma! No strings!

Spectrum has added a new line of StellaNova Floating planet globes! These globes float using a computerized electromagnet. They are adaptable enough that breezes cannot disturb them and you can actually make the planets spin with a little spin! These are 6″  globes that are topped with a historic space probe that explored them! Let’s start with the Floating Moon Globe!

Floating Moon!

Next up is the Floating Venus Globe, which shows what the planet would look like sans atmosphere.

The Floating Venus Globe

And of course we have a Floating Mars Globe as well:

Floating Mars Globe

Then we get to our Solar System’s Gas Giants with A Jupiter Floating Globe

Floating Jupiter Globe

As well as a Floating Saturn Globe – with ring no less!

Floating Saturn Globe

Finally for those who wish to have a complete a set as possible there is the Floating Uranus Globe

Floating Uranus Globe

Neptune globe is pending. No plans for a Mercury globe, however.

Valentine’s Day Giant Microbes Sets!

Need a really off-the-wall quirky gift for St. Valentines day? How about the new Giant Microbes Heart Warming Mini-Microbe Box set? It contains five different mini microbes!

Giant Microbes Heart Warming Mini Microbe Set

You get the mini Human Egg (ovum) Cell, The Sperm Cell, Kissing Disease (mono), penicillin, and a unique pink colored mini amoeba. Great stuff!


But if Valentine’s Day is ‘Black Monday’ to you? What if you’ve had your heart broken or shattered? Giant Microbes has you covered with the Giant Microbes Heart Burned Mini-Microbe Set!


Giant Microbes Heart Burned Mini Microbe Set

Here you have five mini-microbes of all the elements from a (really) bad relationship: The Pox, Chlamydia, HPV, Herpes, & Penicillin!


Both Heart Warming and Heart Burned are available for a limited time only! Be sure to get your in time for Valentine’s Day!

Urban Astronomy – Seeing the Skies in Light Polluted Areas

The sheer, overwhelming amount of light pollution from a city can lead many of its inhabitants to believe that there is no way they can view anything from urban areas. Its not just residents who feel this way, I’ve even talked expert astronomy authors who have told me that there was no reason to get a telescope larger than 3″ diameter for city use as the light pollution would make that extra aperture useless.

The real truth of the matter is a bit different: While city astronomical viewing is hardly ideal, it is far and away from the futile effort that many ‘experts’ would have you believe. In fact, there are a few tricks you can do that may actually give you a decent viewing experience:


Finding the problem light: While ‘light pollution’ is often described as the problem with city viewing the problem can actually be broken down into two separate issues:

1) Direct Lights on your viewing area

2) Ambient light pollution


#1 means things like street lights, alley lights, that light your neighbor put up to light up the side of their house, etc that are pointed right at you or close enough to you to be an issue. Direct light mess up your eye’s dark adaptation and generally mean a poorer light experience. The easiest thing to fight this is to find a place with no lights – but in an age where cities work on the idea that ‘more light = more security/less crime” this can actually be more troublesome than you might think.

#2 , light pollution is the result of all those Urban Lights either being pointed in the sky or reflecting off the ground. This ‘extra light’ will wash out the stars above very quickly. This ambient background light is why, even if you perfectly  dark-adapt your eyes in a city there will still be some problems with seeing the fainter stellar objects as they will get washed out by this excess light

So what can one do to fight these effects and enjoy some urban astronomy?

Look Up!

Its a sad fact of life in the city: People rarely actually look up! And when they do, it is usually to admire some brightly lit building. But if you get in the habit of looking up in the sky at night you will start to notice that on clear nights there are objects in the sky that can be seen, and there’s more than just the Moon up in the sky! Getting into this habit will also let you spot the ideal nights for viewing. Of course, make certain you are not looking up at a tall building or street light first!

Get Away from the City Center

The center area of any city is where its light are brightest and its building are tallest. Getting just a mile or two, or even just a few blocks away from brightest buildings can result in some surprisingly excellent views of the night sky. I myself have been able to naked-eye view the Trapezium in Orion (with averted vision) from both the Ferry Docks in Manhattan, as well as in Northeast Philadelphia!

Get High!

The vast majority of light in a city comes from its street lights. The trend in cities is to add more street lamps instead of removing them, so don’t expect them to go away anytime soon. But the good news is that most of street lights’ light is pointing down (and sadly, being reflected back up, but that’s another story). If you can get above these lights (which usually reach the third floor in most cities) by going on roof of a tall house or deck high above the ground you will avoid a large portion of the light pollution the city produces. Decks and roofs are not ideal for astronomy. Most decks are wood and prone to bouncing when you walk on them, your telescope image will shake accordingly if someone is moving around on your deck. In addition, not all roof decks have access that is easy to bring a telescope up to. Your mileage may vary.

Pick Your Nights Wisely

If you want a chance to see more than just the Moon and Planets, you will need to be choosy about which nights you want to do city observing. In addition to clouds, haze is a frequent factor in the night skies over cities in the warmer months and will spoil most viewing. The best nights for viewing will probably be in the Fall/Winter months.

Adapt your Eyes!

Amateur astronomers write volumes on getting their eyes to adapt to nighttime so that they can get the most out of their telescope viewing. They are, of course, assuming that you are working with excellent dark skies far away from any light pollution, but don’t let that fact put you off letting your eyes adapt. All too many urban astronomers walk out of their lit buildings and glance immediately up into the sky, without allowing their eyes any night adaptation whatsoever. This is not a good way to assess the night sky; instead give your eyes a few minutes to adapt to conditions. To do this avoid looking at any lights. You can sit in a chair and look up at the sky and you can actually see the effects: More and more stars will seem to ‘appear’. Its not that the city sky is improving, its just your eyes adapting to the night.

Choose Your Targets Wisely

Even with all these hints, you should be be judicious in what you want to view in the urban night sky. Trying to view Magnitiude 15-20 (the higher the magnitude, the fainter the object) objects is a daunting task even in the darkest skies and so should probably be avoided. Targets you should consider instead would be:

The Moon: The moon is utterly unaffected by light pollution. In fact, even in the city you might consider using a Moon Filter as the light can be quite bright through a telescope. Keep in mind that the best time to view the Moon is when it is waxing or waning, not when it is full. Why? Because when the Moon is full the light is shining right down of the surface and so you get few shadows to show you details.

The Planets: Jupiter, Saturn, Mars and Venus are also little affected by light pollution. You can enjoy the rings of Saturn as well the moons & bands of Jupiter with any decent telescope. Venus and Mars can also be enjoyed, however the former is very bright and shows only its crescent shape, wheras viewing the latter is often dependent on how close it is to Earth.

Brighter Deep Sky Objects: You won’t get magnificent images of nebulea and galaxies, but you still enjoy them with a decent telescope. The Orion Nebula is one of the easiest objects to find in the night sky, while the Andromeda Galaxy can it least be partially seen on clear nights from the city. Make certain you have a decent star chart or Planisphere to pick your viewing targets.

In Conclusion

Urban astronomy will never match finding true dark skies far out in the country, but don’t let naysayers tell you that you “Can’t see anything in the city”. You most certainly can!

Spectrum Scientifics Microscope Buyers Guide

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!