UserComment is cut-off when the Japanese Characters are used

Hi,

Here is my question about the bug? about EXIF UserComment.

Now I am trying to put some strings in EXIF UserComment Tag in my camera app.

The following code works fine.

NSString *UserComment = @"Can I set Exif UserComment String in such a way? I cannot understand Japanese Characters are not accepted.";
[EXIFDictionary setObject:UserComment forKey:(__bridge NSString *) kCGImagePropertyExifUserComment];

Howver, once I try to put using Japanese characters, my string is cut-off and not all string cannot be set in UserComment in JPEG.

When I write as follwoings,

UserComment = @"そんなこといったって、だめだもんはだめだで、しゃーがないべさ。ほだら。だば、あきらめてしごとしてくんろ。ほりほり。わーったか？ほーり。";
[EXIFDictionary setObject:UserComment forKey:(__bridge NSString *) kCGImagePropertyExifUserComment];

What I get as UserComment in the JPEG file is like this:

そんなこといったって、だめだもんはだめだで、しゃーがないべさ。ほだ

This is useless.

What should I do to SET FULL STRING in UserComment?

Please give me any advise.

Thanks.