Zoom F8n Pro 8-Input / 10-Track Multitrack Field Recorder - Manual (Page 149)

Setting Explanation
30D This rate is used for special applications. This synchronizes with film sound
to be transferred to NTSC using 29.97fps drop frame. The count is 0.1%
faster than the actual time.
NOTE :
Matching frame rates must be set in advance on all connected video and audio devices.
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