Oops! There is something wrong with my foldscope!

Does the title of this blog sound familiar from any of your recent experiences with foldscopes?  It just might, if you are an enthusiastic foldscope user (like me) who wants to put a foldscope in the hands of every school kid.  Perhaps you recently conducted a teachers’ workshop and then let loose the foldscopes into schools.  And then found that in a classroom full of excited kids, unexpected things can happen, even in the folding of foldscopes.

We gathered a few issues from our recent experience of doing a follow-up at various schools, issues that were most commonly overlooked, but resulted in low visibility, blurriness and also false observations.  If students fail to see a clear image or rather, see some dark artefacts, and even believe that this is what they are expected to see, they not only fail to observe and understand, but also lose their interest and motivation.  And then, re-folding a bunch of misfolded foldscopes can be very frustrating for any teacher.

Of course we could begin with care, say with a class of 15 instead of 40, and have each step carefully checked.  But in the flurry of school schedules it might not always happen.  So we get here some common errors with foldscope folding.  Though some of them may sound crude but believe me, they do happen!

    1. 1. Missing lens in the lens slot: This happens when the lens is placed above the top magnetic coupler or no double sided sticker is used between the coupler and the lens.

2. Lower magnetic coupler inserted in reverse orientation in the coupler slot.

Wrongly inserted coupler
Correctly inserted coupler






3. Improper creasing of the folds (especially, the part having the lower coupler which folds back to attach to the lens slot and the folds of the focus ramp)

4. Improperly folded/inserted focus ramp (this causes friction while moving the focus ramp)

5. Improper folding near the slide slots (check the arrows so that when you pull the flap, the opening for the slide slot is visible)

Incomplete folding at slide slot
Correctly folded slide slot






6. Reverse insertion of slide into slide slot (make sure that the coverslip side faces the lens)

Slide inserted in reverse
Slide inserted correctly








7. Adhesive, dirt and fingerprints on the lens (handle the lens carefully, clean it with the cotton swab given and don’t touch it with your fingers)

8. Do not try to keep samples directly on the lens (without a slide) and observe.

So next time , if you or your students are not able to see a clear image through your foldscope, please check the above points and troubleshoot the problem.

We welcome your additional inputs for troubleshooting, and any practical tips for getting foldscopes into classrooms on a large scale.


Debashree (with Udit, Ashalatha, Jayashree)

2 Comments Add yours

  1. Manu Prakash says:

    Dear @TCIS – This is an invaluable post. Thanks for listing all the common mis-steps. Extremely handy guide and valuable document to share with teachers before running large foldscope workshops. We have strongly insisted on the idea that kids should build the foldscope by themselves; and that does slow down the whole process – but slow learning is far more valuable 😉

    Thank you a million times for documenting this here. What a great example of community work. Kudos..


  2. Tulasi Mastanamma says:

    Good one, god observations, besides these i also suggest to keep an eye on folding of Focus raft , if not folded and unfolded properly resulting as flat paper rather than thin end and thick end.

    and in majority of cases as suggested by you placing magnetic coupler and lens together, that’s why I am following 3R+1C ( 3 rectangular couplers + 1 circular lens). Requesting them to make sure whether they have 3R +1C

    Wonderful post useful for many people

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