Ricoh introduced this week its Pentax KF-70 APS-C senor-based digital single lens reflex (DSLR) camera with advanced shake reduction and AF for under $1,000. The compact, dustproof and weather-resistant Pentax KF-70 camera weighs 1.4 pounds (625g), which is 0.1oz (3grams) lighter than the previous K-70…