@Override
    public void write(JmeExporter ex) throws IOException {
        super.write(ex);
        OutputCapsule oc = ex.getCapsule(this);
        oc.write(glowMode, "glowMode", GlowMode.Scene);
        oc.write(blurScale, "blurScale", 1.5f);
        oc.write(exposurePower, "exposurePower", 5.0f);
        oc.write(exposureCutOff, "exposureCutOff", 0.0f);
        oc.write(bloomIntensity, "bloomIntensity", 2.0f);
        oc.write(downSamplingFactor, "downSamplingFactor", 1);
    }
Sets the downSampling factor : the size of the computed texture will be divided by this factor. default is 1 for no downsampling
A 2 value is a good way of widening the blur

@param downSamplingFactor the desired factor (default=1)
jme3-effects/src/main/java/com/jme3/post/filters/BloomFilter.java