Pharyngula

Holiday microscope shopping

Since Phil has suggestions for holiday telescope shopping, I have to offer some suggestions for microscope shopping. If you really want to get a kid interested in biology, a microscope is a great gift, but I’ll give you the price tag right up front: $150 is probably the minimum to get a decent, low-end student scope.

First, a few don’ts. Don’t buy a microscope at a toy store, unless you want cheesy, cheap plastic junk. And probably the most important advice: don’t judge a microscope by the highest magnification. You’ll see lots of ads that shout “1500x!!!”, but trust me: you can’t get a good 100x objective (they get the 1500 by multiplying the 100x objective lens by a 15x eyepiece) for the prices most people can afford. I do most of my professional microscopy work with a 40x objective and 10x eyepieces — you can see much more with a hiqh quality, low power objective than you can with a high power, low quality objective.

When you’re shopping around, most of what you’ll see are called compound microscopes. These are the traditional kind of microscope you’ll see, and they’re often sold with sets of prepared glass slides. You’ll need slides in order to set up specimens, the specimens have to be very thin, and you visualize what you’re looking at by shining light through the specimen — this is called transmitted light microscopy.

You don’t want one of those.

I’ve owned several compound scopes, and they’re wonderful and they give great images…but it takes more prep work (in most cases) to set up the specimens, and you’re going to be much more limited in the range of things you can look at. Imagine that your kid catches a fly and wants to look at it; you can put the wings on a compound scope, but anything else, you’re going to need to cut thin sections or mount bits and pieces on a slide. It’s not fun for most young’uns.

What you want to be able to do is pop the whole animal on the scope and look at it in closeup. You want what is called a stereoscope or a dissecting scope. It’s an instrument that looks something like this:

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(That’s not the $150 model, I’m afraid—it’s the several thousand dollar high end model I use in my lab.)

These beauties have several features that make them a perfect scope for the young student. First, note the working distance, the space between the specimen and the lens. It’s tens of centimeters, enough space for someone to put their hand under there and look at nifty dermal papillae or scabs or their pet gerbil, without squishing or cutting them into thin sections. On a compound scope, you’ve got fractions of a millimeter.

It also uses epi-illumination, or light from above, and what you see is light reflected from rather than transmitted through your specimen. Again, this is to the immense benefit of the pet gerbil. It’s really that easy to use: put the object you want to examine on the base, turn on an illuminator (a desk lamp will work, even), and focus. No great delicacy required, nor do you need to do any special preparation. If you want to do transmitted light illumination, you can buy elevated stands with a glass plate where the black disk is above, and shine light from underneath.

A Leica Wild M3 stereozoom like the one above is overkill for student use, but you can find lots of good scopes at a range of prices at scientific supply houses. Look for educational microscopes; the student models are usually built to be fairly tough and low maintenance. You can find them at these fine institutions (I get no kickbacks from these referrals).

One other thing I’m sometimes asked is about photomicrography — you see something really cool in the scope, so you want to take a picture of it. There are inexpensive scopes with cameras built in, like the QX-5…which is sold in toy stores and looks it, and I can’t really recommend it unless you really want something quick and dirt cheap. You can also get good stereoscopes with built-in digital cameras, but camera technology is improving so quickly that it often means you are paying more than it’s worth to get an obsolet camera system.

I recommend getting really cheap at first and just getting a tripod. Take the camera you use for home photography, and just aim it down one of the eyepieces and take a picture. You’d be surprised at how well this often works. It’s hard to do well with a hand-held camera, though, which is why I suggest using a tripod.

Alternatively, there is a good market now for camera adapters for microscopes. These typically consist of a metal sleeve that attaches to the lens of your camera, and then slides over the eyepiece tube. Zarf Enterprises is the source for a range of different adapters, or if you’re good at shop and know how to mill metal, you can make your own.

Here’s one example of a picture I took a while back, of a freshly eclosed white mutant Drosophila. I just happened to find this pretty pale fly as I was working through my stocks, and on a whim, put her on the stereoscope and snapped a picture — it really is fast and easy.

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It’s also easy to zoom in and look at details, like the bristles on the head. Those microscopes that advertise 1500x magnifications sound impressive, but really, at that mag you’d be staring at a cluster of cells in one small part of a bristle, if you could even get something as large as a fruit fly’s head under the objective, and in a cheap scope, it would be a blurry smear.

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Go ahead, give a kid a nice little microscope for squidmas (or christmas, if you choose to celebrate it) this year. It’s a wonderful way to get the little rascals excited about biology, and you’ll be entertained as they scurry about the house looking for the grossest, creepiest things they can find to look at. The joy on a child’s face as they look into a spider’s eyes for the first time…it’s priceless. Oh, and when they discover the parasites living in their eyelashes…!

Comments

  1. #1 SwelP
    December 4, 2007

    I don’t like your implication.
    Perhaps you little boys would like to follow me around
    online.
    I stopped for coffee & e-mail in Santa Rosa this
    morning.
    After spending the day in traffic, I am in San Jose
    now visiting with family.
    If you are really that paranoid I will drop a line
    from Paradise when I get home.
    You seem clever enough to track me.

  2. #2 Estetik
    December 2, 2008

    Willy, you sound like the guy who traded up from a paper clip to a house! :)

    If anyone’s interested in photomicrography the easy way, get thee to ebay and pick up a Nikon Coolpix 4500. That was the last one they made that was easily compatible with microscope oculars (using adapters, of course, which you’ll also have to scavenge) but they ROCK. Incredibly easy to use and really good pictures.

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    January 4, 2009

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