Sunday, May 17, 2015

FUN WITH MICROSCOPES





FUN WITH MICROSCOPES


A little about my first GOOD (utterly fantastic!) microscope. I got it off Amazon: it’s an OMAX 40X-2000X Lab LED Binocular Compound Microscope with Double Layer Mechanical Stage and Coaxial Coarse/Fine Focusing Knob. They have many similar models, but if you search on the previous, bold font sentence it should bring up what is a great microscope for the casual user who is sick of garage-sale microscopes.




It's resting atop a $5 DAV (Disabled American Vets Resale Shop) power unit. The power unit is just like a powerstrip that you throw on the floor, only it's in a neat box and each of the 5 plugs have their own on/off switch. I flip the main switch and all my gear comes on. The "printer" switch I leave off until I want to make a black and white Dell laser copy of something--it sure beats crawling behind the desk and reaching to the back of the printer and trying to feel where the power switch is! Aux2 powers the microscope, which has a very bright and cool to the touch LED lamp. Cool to the touch is important because some microscopes have hot halogen lights that can fry and kill any bacteria, etc. that you're viewing. Also LED lasts for ever, halogen bulbs require frequent replacement-which is annoying.




My first degree had a concentration in photography and I have built and used optical systems before. One of the first book covers I updated in my art department job at a major publishing company was the one above. I had to find a clip-art microscope and change it to match the blue color used in the series. Everywhere I go: optics, optics, optics!

Anyway, I wanted something to play with when it was too cloudy for playing telescopes, or practicing on my carbon fiber cello (home-made modification of an old Kay cello) . You can skip down to neat photos if you're not shopping for a microscope. 






First: the highest magnification objective lens is oil immersion only. You must put a drop of oil on your slide cover and then lower the lens into the oil to focus on anything. You must NOT do that with the other three lenses. This is what allows the 2000x magnification: light goes through oil instead of unsteady air. It's a fantastic feature at this price. Don't worry though, you can be happy just using the other 3 lenses, which is what I plan on using mostly.

**If you're thinking about buying a microscope and you didn't know what oil immersion objective meant-now is the time to research 'microscopy techniques' along with 'microscope slide preparation' and 'cell staining' techniques and 'dark field' vs 'light field'-- illumination'. I chose the LED light because: they run cold so it won't kill live pond cells like a hot halogen would. They also last longer.


So, how is this scope? Well it's better than what I used in high school and Chem I in university. It's way better than my 4 cheapie Tasco-style garage sale scopes and my homemade macro-bellow system.








This is part of my Frankenstein-scope system. Basically .99cent junk I bought at various garage sales that still did pretty well for taking afocal microphotographs. For a discussion on how easy and cool afocal photography is check my previous blog posts.


































The above photos of a fruit fly were taken with the GARAGE-SALE microscope. Not too shabby, but the Omax does a LOT better as you'll soon see. I caught the fruit fly by setting a flat saucer filled with apple cider vinegar next to a pineapple. 






I took this image with my cellphone held up to the eyepiece of a .99 cent microscope aimed at a laundry dryer sheet at around 50x magnification. Not bad for less than a buck!




...NOW BACK TO THE GREAT NEW MICROSCOPE

Assembly was easy: loosen knob at top to remove top cover. Remove clear cap on underside of head unit. Place head unit on top of scope and re-tighten knob. Pop in the eyepieces: my 20x were **really** tight and hard to install, but it's 40 degrees here and the metal holes that they fit into may have contracted a bit. Just be patient and they'll go in. That's it!! Oh, and plug it in for light.


The objectives are relatively parfocal, meaning when you switch between them you only have refocus using the fine-focus knobs a little. Great feature which makes using it even more of a pleasure. There is a dimmer switch for the LED, and also a diaphragm under the stage-which was half closed when shipped: slide it open for even more light. Again, if you don't know what these terms mean you should start researching 'how to use a microscope'.


Optics appear flat and focused edge-to-edge, which is the opposite of many telescope mirrors I deal with, but that's another story. Each eyepiece spins for diopter adjustment, and the eyepieces slide apart for interpupillary adjustment. Focus with one eye closed using the focus knobs, then switch eyes and focus that eye buy turning that eyepiece itself. Now open both eyes: both will be focused but you'll have double vision: slide the eyepieces further and closer apart. At some point the double vision goes away and in a snap you get a very wide-field view: a single view. It a little like those 'magic eye' optical illusion posters: once you get it-you get it. But it might take a few minutes of fiddling.


I love this microscope, and wished I had bought it years earlier.


On the left side, under the stage is a little black knob that raises and lowers the condenser. Once you've focused--use this knob to back the condenser away from the slide and you'll increase contrast. This helps a lot, especially when things are too washed out with light--and it increases contrast--where just dimming the LED would make everything darker and harder to see.

Basically this is a 'real' microscope, and you should learn how to operate it in the proper manner to use it at its fullest. With that said, except for the 4th lens they throw in (oil immersion) a little kid could easily figure out all the features. There is supposed to be a slip of paper with address to download a manual-but I didn't see it. There are tons of Omax videos on you tube if you need help.


So, what did I look at with my awesome new telescope? You'd think since I live thirty feet from the Rouge River I'd take a water sample like we did in 5th grade and check that out, but no. I ordered some diatomaceous earth from eBay via a vendor named armed_forces_insignia. I received a two packets of white powder very similar to the stuff you dump into swimming pool filters and gardens to kill snails, actually it's pretty much the exact same stuff except one packet was freshwater diatoms and the other were from salt water locales.





I found this round little diatom with my microscope. I believe it is a variety of stephanodiscus. Diatoms are tiny hard shelled beasts that make up diatomaceous earth. Soft-skinned bugs also hate crawling across these (dead) things because they're shells are like broken glass so people use this in their gardens. They come in gillions of different shapes and collecting them can be a life-time hobby. A hobby you can keep on just a microscope slide or two.




Here are some barrel-shaped diatoms from the same samples. This is even more fun than stamp collecting!





I took a video of this cute little guy, gal? It was in the murky tap water that my avocado-pit growing in a styrofoam cup. 












This is the inside of a regular old poppy seed that I left on a wet piece of paper towel for a couple days! You can see the life waiting to jump out of it!












The last three photographs show increasing magnification of some yellowish-green pollen that coated my car in Metro Detroit on 5-17-2015. You can see that as the magnification goes up it gets harder to focus on the entire piece of pollen: microscopes love flat things under cover slips--they have a hard time with "3-d" objects. Be warned, even the ink laying on top of a dollar bill looks like a huge cliff under high magnification. You can usually feel the ink on crisp, new dollar bill--under a microscope you can see the massive depth of the ink on top of the paper and you can only focus on the ink or the paper, not both.






Finally, here are some cat hairs at 1200x under my Omax microscope. 

Remember, if you put a cover slip over these hairs and a dollup of oil on top of that you can ram the oil immersion scope into this and get 2000x magnification! Anything you can grab and fit under your microscope can end up being really cool to look at.






Meow!