I just purchased a pE-4000 to replace an old version of Lumencor Sola SE on a live imaging microscope. After comparing the power level of the systems, I am convinced that the pE-4000 provides stronger illumination at the objective. As the Sola light source can only control intensity of ‘white’ light (rather than individual channels), we have to choose the excitation level according to the dimmest labelling fluorophore. The other channels are in turn exposed to an unnecessary high dose of excitation. The level of photo-bleaching can be high as a result. With the pE-4000, we can control the excitation of the individual channel. It is possible to optimise the excitation intensity according to the labelling, greatly reducing photo-bleaching and photo-toxicity in a live experiment. Due to the difference in the excitation spectrum with the Sola, I was worried about the extra cost of changing the dichroic, excitation and emission filters. The options of four wavelength in each channel (totally four channels) enables me to pick up the correct wavelength according to the old filter/dichroic settings.