If image field is null in kendo grid and you want to show default image then use this code.It will show default image if image field null.
{
field: "Photo",
title: "Photo",
template: function(dataItem) {
return kendo.template(
'<img src="#= Photo #" alt="image" width="100px" height="100px" />'
)({Photo: dataItem.Photo || 'Add Your Default Image Path Here'});
}
width: 100
}