While consumer TVs skipped 3K entirely (jumping from 1080p to 4K), 3K is a native resolution for many professional cameras and smartphones. For example, Red Digital Cinema cameras shoot in 3K, and many flagship Android phones record video at 3200x1800.

Files may be "cam" versions (recorded in theaters) rather than high-definition 4K or 3K quality as advertised. Safe and Legal Alternatives