The Sony a6400 still boasts the 24.2 MP APS-C sensor but has overall better light sensitivity with the native ISO range going from 100 - 32000 and more.
Sony a6400 Review
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Sony a6400: Digital Photography Review
Sony a6400 Review – Mirrorless for Content Creators - Fortress of Solitude
Announced: Sony A6400 has world's fastest AF, selfie screen and Animal Eye-AF and a price of $899 only! – sonyalpharumors
Academic Tech] Sony a6400 'review' – Prof. Peter L. Falkingham
Sony a6400 Review
Sony a6400 review: Digital Photography Review
Sony Alpha a6400 Mirrorless Camera: Compact APS-C Interchangeable Lens Digital Camera with Real-Time Eye Auto Focus, 4K Video, Flip Screen & 18-135mm - E Mount Compatible Cameras ILCE-6400M/B : Electronics
Sony A6400 review