How to exclude one particular field from a collection in Mongoose?

I don't know where you read about that .exclude function, because I can't find it in any documentation.

But you can exclude fields by using the second parameter of the find method.

Here is an example from the official documentation:

db.inventory.find( { type: 'food' }, { type:0 } )

This operation returns all documents where the value of the type field is food, but does not include the type field in the output.

Use query.select for field selection in the current (3.x) Mongoose builds.

Prefix a field name you want to exclude with a -; so in your case:

Query.select('-Image');

Quick aside: in JavaScript, variables starting with a capital letter should be reserved for constructor functions. So consider renaming Query as query in your code.