For a good analysis it is recommended to take the picture with overexposure ( one f-stop). If this is done it is much easier to distinguish between the mites and other particles (like wax). Additional you should trim the picutre so that just the content which shall be analysed is visible. This can be easily done with your standard ANDROID photo application. The following test picutre contains 13 mites. You can use it to test the APP a little bit and play around with the settings.