Five a Second. Chicago's Bell & Howell Co. (cameras) announced that it would put on sale this fall the world's most expensive still camera. Its "Foton" will take five 35-mm. pictures a second, sell for $700. Bell & Howell, which has found that "families of both low and high incomes now spend over $550" for movie equipment, hopes to sell 20,000 Fotons a year.