Converting text and image datatypes

You can explicitly convert text values to char, unichar, varchar, and univarchar, and image values to binary or varbinary with the convert function, but you are limited to the maximum length of the character and binary datatypes, which is determined by the maximum column size for your server’s logical page size. If you do not specify the length, the converted value has a default length of 30 bytes. Implicit conversion is not supported.