I was super excited to receive my Foldscope and get started right away. I’d watched the videos a while ago and had the instructions for reference. Still I made two mistakes I’m sharing that can maybe help someone else just getting started.
The first was silly and easy to fix. I installed one of the magnet couplers backwards so when I tried to fold back the bottom of the lens stage, the magnets repelled each other. All I had to do to correct this was to pop out the magnet, flip it over, and reinstall. Now when the bottom flap folds back, the magnets come together to firmly hold the lens and slide against each other. (They are sandwiched between the magnets).
With the Foldscope completely assembled, the first thing I decided to take a look at was the fern rhizome slide. It was really tough to get the slide into the slide holding slots! I was very afraid of tearing my new foldscope I’d waited so long for! The slide is meant to be inserted in the cuts and you can use the tabs to pull the slit apart. It really didn’t seem like it was the right place to put it, though, because the cut slit seemed much too short for the slide. But be gentle and persist because they really do go there.
Since I was taking photos of what I was doing I decided to put the slide in with the label facing me, so I could still read the label. *This was my second mistake.*
When I tried to view with my eye directly, I had to slide the focus ramp all the way out to the stop tab and it was still a little blurry. It was like I couldn’t move the ramp out (lens down) far enough. I decided to try the other slide but got the same result. I don’t have very good eyesight so I thought it might look better through a camera lens. But when I held the camera up to the lens (I also had to take my phone case off) it wasn’t better. I was kind of disappointed because I was expecting to get a nicer image!
I took a break to throw away all the trimmings and clean up a little bit. I decided to go back to the fern slide because I knew it should have some nice large regular features. I was also only holding my phone camera up to the foldscope because the shape of the back of my phone doesn’t allow me to stick the magnet on directly with the adhesive ring. So I was thinking about how I could get the phone and lens more firmly mounted and -closer- to the sample. Then I realized my mistake!
Because I put my slide in with the sample cover facing away from the lens, it was now farther away from the lens. (The slide is much thicker than the slide cover). I flipped my slide around (which was much easier to insert now that the slit has been used some) and looked through with my eye… success! Focus is achieved with the ramp sort of in the middle of its range. And it was MUCH sharper than before.
I hope my experience might have helped you with your troubleshooting. So much of science is about making small changes and trying again, rarely getting it right the first time. For my fellow new Foldscope explorers, keep at it and let everyone know how it goes. Sharing our experiences will help each other.