Landsat 8 images black?

Question

I am trying to get cloud-free imagery for a specific region during specific dates. I am very new to GEE, but the script below seems to work. However when I look at the imagery that is then printed on the map, all images are black. I've checked and the RGB is correct.

What am I doing wrong?

// A rectangle representing the roi.
var geometry = ee.Geometry.Rectangle(-8.372, 10.017, -2.703, 5.358)

var ic = ee.ImageCollection("LANDSAT/LC08/C01/T1_TOA")
.filterBounds(geometry)
.filterDate('2013-01-01','2013-12-01');

    var c = ic.filterBounds(geometry);

    var withCloudiness = c.map(function(image) {
      var cloud = ee.Algorithms.Landsat.simpleCloudScore(image).select('cloud');
      var cloudiness = cloud.reduceRegion({
        reducer: 'mean', 
        geometry: geometry, 
        scale: 30,
        maxPixels: 1e9
      });
      return image.set(cloudiness);
    });

var filteredCollection = withCloudiness.filter(ee.Filter.lt('cloud', 10));

// Compute the median in each band, in each pixel.
//var median = filteredCollection.median();

print(filteredCollection);

// Select the red, green and blue bands.
//var filteredCollection = median.select('B3', 'B2', 'B1');
var visParams = {bands: ['B4', 'B3', 'B2'], max:0.4};
Map.addLayer(filteredCollection);
Map.setCenter(-6.01, 6.51, 5);

Answer 1

This a common mistake, since you're new in GEE, maybe you didn't notice it. Once created the visParams object, needs to be called from Map.addLayer() function:

Map.addLayer(filteredCollection,visParams);

I recommend you to stretch a bit the visualization range:

var visParams = {bands: ['B4', 'B3', 'B2'],min:0,max:0.25};
Map.addLayer(filteredCollection, visParams);

By the way, there are better options to create what you wanna do. For example, to mask cloud and to apply a reducer (like median or min)