Blank White Screen Issue on High-Resolution OpenFlexure Microscope Setup

General
1

Hi everyone,

I’m building the high resolution version of the OpenFlexure microscope stage using a Raspberry Pi 3B. For my setup, I removed the lens from a Raspberry Pi Camera Module v2 and positioned it at the bottom of the 3D-printed objective lens mount. On top of the Pi camera, I placed an achromatic lens, followed by a 60x objective lens.

I wrote a Python script that uses the Pi camera to display a live feed, but instead of showing the expected image, all I see is a white blankscreen. Interestingly, the brightness of the screen changes when I cover the LED, indicating that the camera is detecting some light, but no focused content appears. I have experimented with placing small objects, like pieces of pepper, at different distances from the objective lens, but the White screen issue persists.

Could this issue be due to misalignment of the lenses, incorrect focus, or a calibration problem? If anyone has faced similar issue?

2

I’d assume it is a focus issue. The depth of field (range that is in focus) for a 60X objective is going to be less than a micron. So you really need accurate positioning to get something in focus. The field of view is also only going to be about 350 microns.

Have you tried to focus the condenser lens so it makes the smallest possible light spot? You can then move the condenser it around. You should at least see it go bright to dark?

The distance between the objective and the object will need to be very small. You should have a microscope slide with the sample facing the objective.