I just bought a secondhand microscope and design some pi cam adapter to check how it could work with openflexure software.
It looks quite bad
I know that FOV is small due to cmos sensor size, and lack on lens btw an objective and cmos sensor.
The design looks like below
I also found out that there is standard mounted lens just below the microscope head…
Do you think that it’s possible calculate position of the lens used in openflexure to make fov wider? Or maybe use different lens…
I also thinking about that way how the cells’ membranes look like. Is it because illumination problems?
The plan is to design stepper motor addapters to control the table and focusing, to have full controlled machine…
The image looks lovely, although as you say the actual imaging is not great. It is indeed possible to calculate the type and position of the tube lens required, but you will need to know something about the microscope as it is.
Are the objectives infinity corrected?
If the lenses are not infinity corrected, how far is it from the lens to the eyepieces? It would be different from ~160mm to need an additional lens.
@j.stirling wrote out a description on how to calculate the lens needed in the knowledgebase. https://openflexure.gitlab.io/-/openflexure-microscope/-/jobs/4835061187/artifacts/builds/info_pages/imaging_optics_explanation.html
Thank you for your answer.
The objectives are 160mm corrected, and the head of the microscope contains a mirror, so it’s hard to measure, total light travel, but it around 140-150mm in total…
I also made a test, removing one of the objective and taking two photos of a ruler placed on the microscope table. 1st phone through the glass element, 2nd directly. The size of the ruler seems to be the same, so the glass element it’s not a lens…
So that sounds to be a standard 160mm microscope. The calculation in @j.stirling’s
explanation that I linked should give you the lens that you need and where to put the camera. It might be that the gap between the objective and the nearest place that you can put the tube lens is too big to get a sensible solution.
The larger sensor of the Pi HQ camera might be more suitable for a longer distance like that, but it is not yet integrated into the Openflexure software.