Troubleshoot
Troubleshooting and Improving the Smartphone Microscope
It may happen that the imaging result doesn't look as good as it could look like. For this we provide a series of explanations to correct for this Overall, with the updated components, the setup should look like something like this:
Perfect Imaging Condition
Wrong Flashlight Mode
- the flashlight has a funky feature to do morse code, this is not helpful, press the button a couple of times to see the brightes light of all different modes
- The stripes you see is the beating of the pwm controlled intensity and the rolling shutter of the camera
Flashlight too much focussed
- The front lens of the flashlight can be focussed - move it to see a more-less homogeneous illuminated sample - this is koehler condition when the led is in focus of the condenser that you move
Flashlight too bright
- use a diffuser or older batteries
Distance between Smartphone and Eyepiece too large
- ensure the distance between phone and eyepiece matches
- the Exit pupil of the eyepiece has to match entrance pupil of the phone
Oblique Angle between Flashlight and Sample (kinda darkfield)
- when moving the light-source you will see effects such as shadows or reliefs. This is due to the WOTF
Ok Imaging with diffuser between flashlight and sample
- incoherent imaging reduces the contrast but gives nice homogeneous illumination
Overexposed but good imaging (koehler illumination)
Oblique Illuimation (Darkfield)
- very opblique illumination, no direct light hits the camera sensor