HttpTransportBindingElement httpBindingElement = new HttpTransportBindingElement();
httpBindingElement.AuthenticationScheme = AuthenticationSchemes.Basic;
...
PTZClient ptzClient = new PTZClient(customBinding, endPointAddress);
ptzClient.Endpoint.Behaviors.Remove(typeof(System.ServiceModel.Description.ClientCredentials));
UsernameClientCredentials onvifCredentials = new UsernameClientCredentials(new UsernameInfo(_username, _password));
ptzClient.Endpoint.Behaviors.Add(onvifCredentials);
ptzClient.ClientCredentials.UserName.UserName = _username;
ptzClient.ClientCredentials.UserName.Password = _password;

TransportSecurityBindingElement transportSecurity = new TransportSecurityBindingElement();
// UsernameCredentials is a class implementing WS-UsernameToken authentication
transportSecurity.EndpointSupportingTokenParameters.SignedEncrypted.Add(new UsernameTokenParameters());
transportSecurity.AllowInsecureTransport = true;
transportSecurity.IncludeTimestamp = false;
TextMessageEncodingBindingElement messageEncoding = new TextMessageEncodingBindingElement(MessageVersion.Soap12, Encoding.UTF8);
HttpClientCredentialType[] credentialTypes = new HttpClientCredentialType[3] { HttpClientCredentialType.None, HttpClientCredentialType.Basic, HttpClientCredentialType.Digest };
...
foreach (HttpClientCredentialType credentialType in credentialTypes)
{
    BasicHttpBinding httpBinding = new BasicHttpBinding(BasicHttpSecurityMode.TransportCredentialOnly);
    httpBinding.Security.Transport.ClientCredentialType = credentialType;
    BindingElementCollection elements = new BindingElementCollection(new BindingElement[1]{messageEncoding});
    foreach(BindingElement element in httpBinding.CreateBindingElements())
    {
        if (element is TextMessageEncodingBindingElement)
            continue;
        elements.Add(element);
    }
    CustomBinding customBinding = new CustomBinding(elements);
    DeviceClient deviceClient = new DeviceClient(customBinding, endPointAddress);
    if (credentialType == HttpClientCredentialType.Basic)
    {
         // Set all credentials, not sure from which one WCF actually takes the value
         deviceClient.ClientCredentials.UserName.UserName = pair[0];
         deviceClient.ClientCredentials.UserName.Password = pair[1];
    }
    else if (credentialType == HttpClientCredentialType.Digest)
    {
        deviceClient.ClientCredentials.HttpDigest.AllowedImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Delegation;
        deviceClient.ClientCredentials.HttpDigest.ClientCredential.UserName = pair[0];
        deviceClient.ClientCredentials.HttpDigest.ClientCredential.Password = pair[1];
    }
}