Nikon Coolpix L110 Q&As

I have a Nikon L110 Coolpix which I use mostly for movies. It works well and has a nice image even though it's limited to 720p. However, whenever anything very light passes through the image (particularly when the image is overall somewhat dark) the iris goes nuts and flickers the image until the light object stops or is gone. The iris setting is automatic in this camera so there is no way to lock it down. Any ideas of how to get around this?  Thanks!