Microscope for micro welding and hand engraving application

hi alberic.

thanks for your quick response.
i have read your writings many times.
after some search and watching the following videos all microscopes having optional external darkening filters.
still i have a lot of questions, why not ?

https://www.youtube.com/watch?v=te9DNO76b08&list=PLts8iuZLOafHwFHA9-ZCX0RTSAUkYQ7TC

http://www.sstmicrowelding.com/en/products/spot-tig

MICRO WELDING (TIG V-01 JAPAN)

after second 0.25 Como Soldar ouro, prata, platina, aço inox

thanks for the time devoted !