Tuesday, April 28, 2020

Hypercentric optics: A camera lens that can see behind objects

Telecentric and hypercentric optics are very different from our eyes or normal camera lenses. They have "negative" perspective or no perspective, respectively, leading to very unusual images. In this video I show how to use a common fresnel lens in the creation of your own telecentric optical system. 
Fresnel lens, 300mm dia. 200mm FL is sold out... https://www.amazon.com/gp/product/B071ZQL9YZ/ 

Idea to use macro tubes for telecentric conversion of normal lenses came from here: http://www.4photos.de/camera-diy/Telecentric-Lens.html 

Commercial hypercentric and telecentric lens maker: https://lw4u.com/ 

Paper on making telecentric lenses with fresnel front elements: https://sci-hub.tw/10.1117/12.455256 

Sunday, April 5, 2020

Alpha radiation makes sparks, detects smoke, and eliminates static cling

Interesting applications of a strong polonium-210 alpha radiation source.  The half life is only 140 days, so the Staticmaster brushes must be replaced every year or so.

Great technical article on ionization smoke detectors: https://circuitcellar.com/wp-content/uploads/2012/06/CC2011110601.pdf

Staticmaster refill: https://www.amazon.com/Static-Master-4331991414-Static-Master-Refill/dp/B0000ALKDH/

Ionization chamber: https://www.aliexpress.com/item/32838644316.html

Carl Willis' video on spark gap detectors. (check out his whole channel) https://www.youtube.com/watch?v=-8GlzUjYazs

Polonium poisoning: https://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvinenko

Mightyohm geiger counter: https://mightyohm.com/blog/products/geiger-counter/

Applied Science on Patreon: https://www.patreon.com/AppliedScience