Handbags   (The sad, the bad and the ugly. Non-productive stuff here.)

Kenny - there's a comment from below the article (10/02/12 10:29) that seems to explain it:

'Using a camera lens in the reverse position was known and used well over 60 yrs ago in the time before the development of the modern specialised "macro" objectives. It is based upon a well-known optical principle ... that in the case of a "normal" camera with the lens in "normal" position, the distance between the subject and the front of the lens is very much greater than the distance between the back of the lens and the image formed on the film or CCD sensor. The lens design is corrected on this assumption. However, when doing close-up photography, the distance between subject and lens now becomes very small and can well be less than the distance between the rear of the lens and image. Reversing the lens orientation gives the photographer a better-corrected lens system for this work. With that said, these photos are very nice and demonstrate that the photographer thoroughly understands his equipment.'