Today I was making some tests on the different apertures, focus length and depth of field. Because the lens is detached from the body of the cammera it shows 00mm however I write down the numbers I was using. At last I had 20 different pictures of the same thing just changing its magnification rate. I must say it was an interesant experiment, but at the end I found out that the background also was playing a role on the exposition results of the picture. so This "last" picture I did it with a black background and I put more attention on its composition and colours than in getting maximum magnification.
Canon EOS 500D ISO 200 0.5"
Reversed Lens on 35mm
size of conch less than 1 Inch.