http://farm3.static.flickr.com/2560/...c650430b_o. jpg Thanks all for a good and informative thread. The above image and more here show the "flat" umbrella shape of the PLM. Buff et co try to argue themselves away from the need of deep
paraboles. http://www.alienbees.com/images/deep-para.jpg "Parabolic reflectors are often misunderstood by photographers. A common ...