Oloong SP-690 II TTL Auto Zoom Speedlight/Speedlite Flash for Nikon D3000,D5000,D3100,D5100,D7000,D50,D60,D70,D70S,D80,D90,D200,D300,D300S,D700,D3S | Eachshot.com
Nikon D50 Teardown & Review *Part 2/4* Electronics - How it works / older Nikon DSLR quality... - YouTube