Looking at algae with Foldscopes

  • Cynthia Gonzalez

20160209_115940Figure 1: Folded up Foldscope!

Folding up some Foldscopes

My peers and I in CSUMB’s Marine Ecological Systems class were fortunate enough to receive Foldscopes. These little tools aren’t just fun to look at–they’re fun to use! It takes a little trial and error to get used to them. After folding it up in class, I went home and tried familiarizing myself with the scope by looking at a few easily accessible objects under the lens (like a strand of my hair, grains of salt, and an ant sacrificed in the name of science).  At first, I was struggling and couldn’t see anything too clearly. I then realized I had my lens plate in the wrong way (figure 1). After flipping the plate around I was able to see objects in better detail  (figure 2).  There are plenty of ways to use and customize these Foldscopes. As you familiarize yourself with it, you learn more about what works and what is the best way for you to use your scope

20160319_221540Figure 2: An area in the Elkhorn Slough. The two smokestacks in the background belong to the Moss Landing power plant.


Algae at the Elkhorn Slough

Our class went out to the Elkhorn Slough in Moss Landing, California on February 18th, 2016 (figure 2).  The Elkhorn Slough is the largest tidal salt marsh outside of the San Francisco Bay area, with a reserve size of approximately 1700 acres. Over 135 aquatic bird, 550 marine invertebrate, and 102 fish species use the slough as habitat (http://www.elkhornslough.org/).

While the water looks very blue in some pictures (and in some instances, in person!) the water actually has a green tinge to it (figure 3). The green tint indicates that the water is nutrient rich. Several organisms like algae thrive in nutrient-rich waters (figure 4). I collected a small sample of algae from the genus Cladophora and analyzed it under my Foldscope later that day.

20160218_103434Figure 2: An area in the Elkhorn Slough. The two smokestacks in the background belong to the Moss Landing power plant.


20160218_104143Figure 3: Water color in the Elkhorn Slough. From afar, the slough has a bluish hue. Up close, the water has a green tint.

2016-03-19 20.37.16Figure 4: Algae growing along a shoreline in the Elkhorn Slough.

Setting up the foldscope for photography

It took me a while to figure out a photography set up that worked for me. What worked best for me was using my old Samsung Galaxy III as the camera (figure 6). I made use of the magnets to connect my phone to the foldscope. I taped the magnets onto my phone as pictured in figure 6. On the foldscope, I taped the magnets onto the inner arm that crossed slide stage (figure 7). The light source I used was the flashlight setting of a Samsung Galaxy Note 4.

After preparing my samples on a glass slide, I connected the Galaxy III to the foldscope. I then turned on the flashlight on my Note 4 and set it face down on the desk so that it served as the light source.  Moving the Galaxy III to the left, right, top, and bottom allowed me to explore and focus around different areas of my slide.

20160319_221723Figure 6: Setting up my Foldscope for photography. Note the placement of the magnets on the back of my Samsung Galaxy III phone.

20160319_221945Figure 7: Taping the magnets along the inner-side of the Foldscope arm.

Algae close-ups

I was able to get several images of algae with my set up. Below I have shared five that capture the range of images I collected.

20160218_115017Figure 8: Algae close-up picture one.


20160218_115042Figure 9: Algae close-up picture two.


20160218_120056Figure 10: Algae close-up picture three.


20160218_120705Figure 11: Algae close-up picture four.

20160218_120709Figure 12: Algae close-up picture five.

As you can tell, the images vary both in clarity and subject. I believe most of the variability comes from the fact that the photography device I used was old and not as powerful as the cameras in newer phones like my Note 4. The images still manage to capture a level of detail that simply cannot be appreciated by the naked eye.  I was fascinated with how I could see with what I assume are small cells in figure 11.  It was also really fun to put the slide into the scope and anticipate what I would see in my camera!

Thoughts and future directions

During our class excursion, I noticed mats of Cladophora algae floating around. I do not know much about this algae and I have a lot of questions about it. I wonder how these organisms fare in the slough. Do they bloom in period of high nutrients? And if so, to what extent? Are these algae important in the slough ecosystem, or do they out compete other equally or more important algae? I am curious!

In the future, I want to try using a better camera to take pictures. Although it is easier to use the Galaxy III to take pictures with the Foldscope set up (it  is smaller, lighter, and I am okay with it accidentally getting dropped around in the field), using the Note 4 could allow me to see things in better detail because it has a stronger camera.

I am looking forward to using this Foldscope more often both inside and outside of


This article and its reviews are distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and redistribution in any medium, provided that the original author and source are credited.