Zip file with utf-8 file names

In my website i have option to download all images uploaded by users. The problem is in images with hebrew names (i need original name of file). I tried to decode file names but this is not helping. Here is a code :

using ICSharpCode.SharpZipLib.Zip;

Encoding iso = Encoding.GetEncoding("ISO-8859-1");
Encoding utf8 = Encoding.UTF8;
byte[] utfBytes = utf8.GetBytes(file.Name);
byte[] isoBytes = Encoding.Convert(utf8, iso, utfBytes);
string name = iso.GetString(isoBytes);

var entry = new ZipEntry(name + ".jpg");
zipStream.PutNextEntry(entry);
using (var reader = new System.IO.FileStream(file.Name, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
    byte[] buffer = new byte[ChunkSize];
    int bytesRead;
    while ((bytesRead = reader.Read(buffer, 0, buffer.Length)) > 0)
    {
        byte[] actual = new byte[bytesRead];
        Buffer.BlockCopy(buffer, 0, actual, 0, bytesRead);
        zipStream.Write(actual, 0, actual.Length);
    }
} 

After utf-8 encoding i get hebrew file names like this : ??????.jpg Where is my mistake?