The TTL BaLanced fill (TTL BL) mode is the most complicated flash mode on the Nikon Speedlights. This mode is (so far) not found on any third party flash units.

TTL均衡补充（TTL BL）模式是尼康高速闪光灯最复杂的模式，该模式（目前）还没有其它闪光灯使用。

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The BL-5C is one of just 14 different batteries used in Nokia products so be sure to check the list below to see if your phone is one of the 52 Nokia handsets affected.

ENGADGET: Nokia-branded batteries at risk of overheating -- 46 million devices affected