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closeSpacing of Components
Posted by vansmith on 01 Apr 2011 at 16:40 GMT
Thank you for this excellent work!
In your article you state that:
"The point of best focus was determined to be 0.722 mm in front of the lens...
In other cases, the sample was held by hand and separated from the microscope by a rubber spacer that automatically placed the image in the proper plane such that the center of the field was in focus."
From this I understand the spacing of components to be as follows:
1) Cellphone camera lens cover glass (phone body)
2) Ball lens retained within hole in rubber membrane
3) Spacing of approximately 0.772 mm (established by a rubber spacer membrane of about 0.5mm plus a cover slip for the specimen slide)
4) Specimen
5) Glass slide
The specimen to be examined is placed on a glass slide, protected with a cover slip and then placed directly against a thin spacing membrane (with opening over lens) over the rubber sheet ball lens holder.
Is this correct?
I am interested in making a unit suitable for use by village health workers and water quality technicians in the developing world . I envision using a small LED flashlight with suitable diffusers as a light source. An optional 45 degree mirror for sunlight illumination would be possible. Standard PVC pipe could be heated and molded to form the body for holding & positioning components.
Thank you!
vansmith