Tagged: damaged lenses?
December 16, 2017 at 2:12 pm #29248
I had great fun putting my Deluxe Foldscope together, but neither lens is clear. Each lens has a black “amoeba-shaped” spot in middle of the field, and the rest of the field is “crazed”. Could the lenses have been damaged in the manufacturing process?
I am giving four other Foldscopes as Christmas presents, and I am afraid that the kids will be as disappointed as I am.
Can I get replacement lenses?
I am open to suggestions for how to view objects with the Foldschope.
January 2, 2018 at 6:11 am #29771
- This topic was modified 4 months, 1 week ago by lreinhar.
I’m sorry to read that your foldscope’s lenses are dirty. Have you tried to clean them up with the cotton swab ?
What about the other foldscopes ?January 7, 2018 at 2:13 pm #30000
I am having a similar problem with lenses. I find that the focusing wedge is useless; the lens must be VERY close to the slide for focusing, closer than can be achieved with the focusing wedge in place.
I found an alternate way to check lens performance without assembling the entire foldscope;
see my note below. I checked the lenses on 2 classroom sets (40 lenses total).
My suspicion is that there is a problem with the production run of the lens mounts.
I doubt that (at this price) anyone tested the individual lenses.
I am also finding that the slots for the slides in the foldscope are not long enough. I had to lengthen the slots with an exacto knife.
*I will describe my attempts to check my two boxes of Basic Classroom FoldScopes.
I think my procedure is quite simple.
My light source is the overhead lamp in our dining room. I redirect the light by placing a hand mirror one the table so the light from overhead lamp is in my eyes.
I am using:
one of the fern rhizome prepared sample slides, and
one of the magnetic coupler washers and
one lens in its black holder.
I also have a package of blank microscope slides with cover slips.
I place a magnetic coupler washer on the table, black side up.
I place the prepared slide on the magnetic coupler washer, label and sample side up. I center the sample over the hole in the magnetic coupler washer.
I place the lens on the slide, silver side down. So, I have a sandwich of magnetic coupler, prepared slide and lens The magnets hold the sandwich together.
I hold the sandwich up to the light, and hold it close to my eye. Sometimes I have to readjust the sandwich to center the sample on the lens. I can see the cells of the sample. For some of the lenses, the focus is good. In this particular lens,
the focus is kind of poor. I can improve the focus by prying the lens away from the slide OR by adding one or two cover slips between the lens and the microscope slide.
I tested all 40 of the lenses on my classroom FoldScopes. Three or four of them gave the best images; very much in focus, good contrast, etc. Most gave reasonably good images that could be improved using the cover slips. A couple of them gave images that were out of focus and couldn’t be improved with the slide cover slips.
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