Grades: 3 to 12+
Duration: 2-4 Hours
Supplies: 3x 4 ½” x 5/16” carriage bolts 9x 5/16” nuts 3x 5/16” wing nuts 5x 5/16” washers ¾” x 7” x 7” plywood — for the base ⅛” x 7” x 7” plexiglass — for the camera stage ⅛” x 3” x 7” plexiglass — for the specimen stage Scrap plexi (~ 2″x 4″) for specimen slide (optional but useful) laser pointer focus lens (use two for increased magnification) LED click light (necessary only for viewing backlit specimens) Tools: Drill Assorted bits Ruler
Gather your supplies
- 3x 4 ½” x 5/16” carriage bolts
- 9x 5/16” nuts3x 5/16” wing nuts
- 5x 5/16” washers
- ¾” x 7” x 7” plywood — for the base
- ⅛” x 7” x 7” plexiglass — for the camera stage
- ⅛” x 3” x 7” plexiglass — for the specimen stage
- Scrap plexi (~ 2″x 4″) for specimen slide (optional but useful)
- laser pointer focus lens (use two for increased magnification)
- LED click light (necessary only for viewing backlit specimens)
- Assorted bits
Orient your lens
The lens is not symmetrical when viewed from the edge. You’ll see a thin, translucent strip (~1mm) on one side of the otherwise transparent lens (in this photo it’s shown on the left side). This side must face away from the camera. You can determine the correct orientation by sticking the lens between the prongs of a hairpin, then taping the rig to the back of your smartphone as shown in the second photo here. The correct orientation will provide you with a larger field of view.
As it is, you can take reasonably good macro photos with just this lens and your smartphone. But it’s extremely hard to keep the phone steady when taking zoomed-in photos. That’s why you need to build a stand!
Cut and Drill the Stand
Mark the top of the plywood base at the front 2 corners, 3/4″ in from both the sides and the front edge. Make a third mark centered 3/4″ from the back edge.
Stack the plexiglass camera stage (7″×7″) on top of the base. Then stack the specimen stage (3″×7″) on top of the camera stage, with 3/4″ of the specimen stage extending over the front of the base. Clamp and drill through the entire assembly.
The bolts that stick up through the base must be counterbored in order for the stand to sit flat. Flip the base over and counterbore the holes with a spade bit to accommodate the bolt heads.
Mount the Lens
Find a drill bit slightly smaller than the diameter of the lens. Then measure, mark, and drill a hole in the camera stage, 3/4″ from the front edge, in line with the bolt holes.
Press-fit the lens into the hole. If it doesn’t quite fit, use a file or sandpaper to enlarge the hole. Work slowly and test the fit often. It’s easy to overshoot and make the hole too large! You can remedy this with tiny bit of glue, but be very careful not to get glue on the lens surfaces.
When using the stand, it’s important to have the lens as close as possible to the camera. If you plan to keep your phone in a case when you use the stand, then leave the top of the lens slightly exposed so that it will rest closer to the camera. Otherwise, mount the lens flush with the stage.
Get Lenses HERE
OPTIONAL: mount a second lens
By adding a second lens magnification can be as high as 375x, plant cells and their nuclei are easily observed! In addition to allowing the observation of cells, this setup also produces stunning macro photography.
If you’re using 2 laser lenses, mount them one above the other in the camera stage, inserting one lens from below and the other from above. This increased my magnification to ~325x.
Be careful not to let these lenses touch, and install them as level as possible. Failure to do so can cause aberrations in the image.
Build the base
Start with washers and nuts to hold the 3 bolts tight to the base. Add some upside-down wing nuts and then washers to the 2 front bolts. Then place the specimen stage on top of these washers.
Add a nut to each bolt, and lower them about 1/2″. Then put a compression spring over each front nut and bolt, and rest the camera stage on top of the nuts.
A level is handy here to make sure that the stage is actually flat. If you don’t own a level there are plenty of free level apps for a phone! Use wire cutters or pliers to trim or adjust the springs if necessary. When the stage is level both front to back and left to right, tighten down the final nuts.
The compression springs keep the specimen stage stabilized and allow you to make far finer adjustments with the wing nuts. Without these springs, the specimen stage can tilt one way or another if the load is imbalanced or if the bolt holes are too large.
Make the slides
The focal length of the lens is very short and the specimen stage can only be raised so close to it because of the nuts holding up the camera stage. Using a transparent sample slide fixes this problem and makes manipulating samples while viewing easier. Simply cut a 2″×4″ piece of plexiglass.
Take and SHARE your Photos and Videos!!!
You just made a digital microscope!!
Align your smartphone camera lens with the microscope lens. Bring the object into focus by slowly turning the wing nuts on either side, then use your phone to take a picture or video, or even zoom in for a closer look.
How are YOU using this in the classroom? Tell us in the Comments.