Testing my options for Macro photography. I put my extension tubes on 3 different lenses to see what would get the best closup. 40-70mm, 50mm, and the 100mm macro lens. 100mm macro lens wins the shootout. I could get more of a closeup, and it was far easier to use. The working distance on the other lens was very small... so I will stick with the 100mm.
And the Test photos...
Starting with 3rd place - worst quality and most difficult to use. The 17-40mm lens at 40 mm with 21mm of extension tubes. Focusing range was VERY shallow, and about 1/4 inch in front of the lens. Blocked out almost all light!
2nd place - The 50mm f/1.4 lens with 65mm of extension tubes. Not bad. Shallow range of focus. About 2 inches in front of the lens.
1st place - Goes to the 100mm f/2.8L Macro lens with 65mm of extension tubes.