Dive Briefing Copyright © 2004 Craig "Monty" Sheppard and Michelle Gaut

- click to see photos -

August 13, 2004 -Kovohika Island, Florida Islands (Dive 2)

Max Depth: 91'
Dive Time: 64 min, 11:25
Temperature: 81 °F
Nitrox PO2: 32%
Camera: Canon 1Ds, 180mm USM Macro, B+W 72mm +2 Diopter, 2 x Ikelite DS-125

First dive with the 180mm macro lens! I found that in the Canon camp, it is nearly impossible to stack the 100mm macro with a 2X teleconverter because 1) an EF12 or EF25 extension tube is necessary to mate the two parts, and 2) the necessary focus gear is too long and easily becomes elliptical (non-functional) during use. Unfortunately, the 180mm macro is a 1:1 lens, whereas stacking a 100mm macro with a 2X and EF12 gets you past 2:1. A +2 diopter is useful, but I think a +4 or so would be much more effective. I'm going to switch to a +3 (the strongest 72mm diopter I own) for the next dive.

Not long after dropping in, I discovered a large long-tentacled anemone with two large clownfish and several small juveniles in it. One of the large inhabitants was showing signs of aerating an area just in front of the anemone, and upon moving in I discovered a patch of late-stage eggs! The next 45 minutes were spent here observing and shooting photos. The 180 is definitely easier to use than a stacked 100 (clear image, usable auto-focus, ability fo stop down further without diffraction problems), but I wish it would focus closer.

Dive Briefing Copyright © 2004 Craig "Monty" Sheppard and Michelle Gaut

August 15, 2004 - Kovohika Island, Florida Islands (Dive 11)

Max Depth: 70'
Dive Time: 57 min, 14:06
Temperature: 82 °F
Nitrox PO2: 32%
Camera: Canon 1Ds, Canon 180mm Macro, B+W +3 diopter, 2 x Ikelite DS-125

A steep wall merges into a blunt knife-edge jutting out from the island. Further out is another knife edge, but the top of that formation is at 100', so none of us went down to see it. I spent most of the dive photographing two pygmy seahorses (bargibanti and denise), and then had to do the ol' mid-water safety stop in current, since there wasn't any shallow reef to be seen. While still acceptable with a +2 diopter, the 180mm macro starts to become unusable with a +3 diopter; the corners exhibit severe chromatic aberration and extreme blurring. The picture within the viewfinder is also compromised, making it difficult to gauge a sharp focus. It may be that there is no way to shoot supermacro with a Canon setup, when the focus gear must mate with a gear on the housing body (and not the lens port). A extension tube would provide closer focus without compromising sharpness, but it might make the required focus gear too long to stay circular during use.