Bush Warblers are photographers nightmares. You can locate them all by call, but seeing them is another issue (despite often being only a few feet away), let alone getting a good photo... I tried vainly for quite a while to get a decent photo of a Brownish-flanked Bush Warbler. I finally managed to get some okish shots last week.
This great skulker is a quite common winter visitor at Hanoi, in scrubs at the edge or inside wooded areas.
The archetypal small boring brown bird, the famous "Little Brown Job" or LBJ of the British birders.
It occasionally deigns to leave the cover and perch in the open... but just few seconds, not more !
Note the flashing pale underwing-coverts