I am using a sony digital camera.
I always add a UserComment to my photo by a software named "Sony PlayMemories Home". The UserComment display fine in PlayMemories Home, but it doesn't display correctly in Irfanview. I am using Chinese characters.
I notice the encoding of UserComment is Unicode. After I reload the text in Unicode, the characters of UserComment looks fine.

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Hope EXIF plugin have good UserComment Unicode support and good CJK characters support.