CREATE TABLE table_29366 ("Vertical" FLOAT, "Horizontal" FLOAT, "Aspect ratio" TEXT, "Pixel aspect ratio" TEXT, "Scanning" TEXT, "Frame rate  (  Hz  ) " TEXT)

Name the least horizontal for smpte 259m three quarters
SELECT MIN("Horizontal") FROM table_29366 WHERE "Pixel aspect ratio" = 'SMPTE 259M three quarters'
SELECT MIN("Horizontal") FROM "table_29366" WHERE "Pixel aspect ratio" = 'SMPTE 259M three quarters'