Here are some Nikon D810 ~300 sec shots taken at different ISO settings
http://s3.amazonaws.com/IliahBorg/Nikon ... C_1686.NEF
http://s3.amazonaws.com/IliahBorg/Nikon ... C_1685.NEF
http://s3.amazonaws.com/IliahBorg/Nikon ... C_1684.NEF
http://s3.amazonaws.com/IliahBorg/Nikon ... C_1683.NEF