Although it may not be in the intended use, I bought it as a lens that expands a fine pattern. I tried to purchase 4 sizes from 2 mm to 0.6 mm, but 2 mm and 1 mm were seen as it was rather pretty balls, but it became an elliptical shape like 0.8 mm egg and slightly irregular shape, 0.6 In mm it was perfectly shaped like a potato and it was not very uniform as a lens.
For the convenience of the manufacturing method Originally this may be the limit, but it is appreciated if you can specify information on the sphericity a little more whether it can be used as a lens or not (Because it can not be judged only with image pictures)
Since it was 0.7 to 0.99 mmφ, I mainly wanted about 1 mm φ, so I bought it, but I purchased it so much, but there were not much bigger ones, there were many things like 0.8 mm φ or so, and I had a hard time choosing a bigger ball.
I rented a machine and needed an experiment within a limited time. I arrived immediately this time so it was very good. It seems that it was obtained somewhat cheaply when purchasing from the laboratory supplies agent. However, there is a high possibility that they could not be brought on the next day. This time it was necessary to hurry, besides the things that had been prepared beforehand since the rental machine arrived, so I purchased it here.