CREATE TABLE table_2962 ("Name" TEXT, "Aperture m" TEXT, "Aper. in" TEXT, "Mirror/type" TEXT, "Nationality/Sponsors" TEXT, "Site" TEXT, "Built/Used" TEXT)

How many nationalities/sponsors for mirror/type schmidt uv?
SELECT COUNT("Nationality/Sponsors") FROM table_2962 WHERE "Mirror/type" = 'Schmidt UV'
SELECT COUNT("Nationality/Sponsors") FROM "table_2962" WHERE "Mirror/type" = 'Schmidt UV'