GeoJSON features are added to null island when dynamically loaded in Openlayers3

Question

I'm trying to add features from a GeoJSON response in openlayers3. Using the default loading method works great:

layer.setSource(new ol.source.Vector({url:url, format:new ol.format.GeoJSON()});

But I need error handling, So I use the response from a standard jquery loader like so:

var features = new ol.format.GeoJSON().readFeatures(response);
layer.setSource(new ol.source.Vector({features:features}));

All the features appear bunched on null island in a sort of a mini-map:

And a closer look reveals the features:

edit:Specifying the data/feature projection doesn't work either.

EDIT: I finally fixed it, Here's the code:

var reader = new ol.format.GeoJSON({
    defaultDataProjection:'EPSG:3857',
    Projection:'EPSG:3857'
});
layer.getSource().addFeatures(reader.readFeatures(res,{
    dataProjection:'EPSG:4326',
    featureProjection:'EPSG:3857'
}));

What an absolute nightmare that was.

Answer 1

I fixed it by playing with the projection options:

var reader = new ol.format.GeoJSON({
defaultDataProjection:'EPSG:3857',
Projection:'EPSG:3857'
});
layer.getSource().addFeatures(reader.readFeatures(res,{
    dataProjection:'EPSG:4326',
    featureProjection:'EPSG:3857'
}));