Tuesday, August 26, 2008

10 frames per second

I have recently upgraded my underwater camera system, from a Canon EOS1DsMKII to an EOS1DsMKIII in a Seacam housing. Of course, the marquee advantage of the 1DsMKIII is the 21 megapixel full frame sensor and the extraordinary detail and color the 14-bit processing reveals. The files truly are stunning, but one of the coincident advantages to housing this system is that the 10 megapixel 1DMKIII is exactly the same size, and therefore fits in the same housing.

This creates multiple advantages:

1. A less expensive back-up camera.
2. A 1.3 crop factor on the sensor when a different perspective on the same lens is required. I especially like the wide angle field of view of the 15mm fisheye and 14mm wide angle when used on the 1DMKIII.
3. The 10 frame per second capture rate is a powerful tool for certain dive related imaging scenarios, like the giant-stride series shown here.

Admittedly, high res generally trumps frame rate on continuous shutter for most underwater applications, but the versatility of having two significantly different tools fitting in the same housing is very powerful.

Saturday, August 16, 2008

A shark dead for no reason

Snapper Ledge Deserves SPA (Sanctuary Preservation Area) Status

Is there anything we can do about the ongoing carnage that anglers and spearfisher-persons are doing at Snapper Ledge off Key Largo? I ask because it is an absolute gem of a reef, the fishiest reef in the whole Florida Keys I think. But, it is open for any and all to take fish there. There is only one mooring buoy and I’ve seen it occupied by boats teaching spearfishing classes, and more disturbing is what is being done to the nurse sharks there.

I don’t dive this spot all that often, mostly just during my photo classes, but now on 3 separate occasions I’ve found nurse sharks alive on the bottom, but just barely. They’d been apparently caught or speared for sport, and then left to die. It took them several days to finally die, but sure enough, we found them later in the week dead on the reef.

This week it was even more outrageous. I found a nurse shark curiously lethargic on the bottom on Sunday. He had been stabbed through the back, and eviscerated. I looked at his belly and the entrails were hanging out. He was alive but nothing anyone could do to help that poor guy. Someone probably caught him, stabbed him, gaffed him, and threw him back in to die.

I had 16 photo students with me to witness this barbaric travesty on Sunday, and then were with me on Wednesday to find the white and lifeless corpse on the bottom, tucked in next to the majestic schools of grunt and snapper we were there to celebrate. I have photos of the whole series, including the vibrant shark who became detritus on the seafloor by the act of some ignorant or malicious person. It was pretty outrageous really.

I recommend this marquee dive site be protected as a Sanctuary preservation Area, SPA, just like Molasses Reef is protected. There are plenty of other places to spear fish off Tavernier and Islamorada. We’re only talking about a few hundred square meters that needs protection, because clearly, left to their own devices, uncaring and uneducated cretins are decimating the marine life there for no good reason.

To sign a petition to make Snapper Ledge a SPA, please visit:

Thursday, August 14, 2008

More on UW TTL with digital cameras

I'm teaching another photo course this week, and enjoying seeing so many different shooters with so many different systems participating.

As is our norm, we do an exposure test on the first day, to make sure distance estimation, strobe aiming, and camera/strobe performance is as expected. After years of seeing marginal (and worse) TTL performance from digital cameras and housings, I was very impressed to see the consistency of exposure rendered by several different housings, all outfitted with Ikelite DS125 strobes.

Here are some samples:

The top series is one I shot on full manual, showing the difference one stop makes, absent TTL correction.

The second is by Jim Gombold with a Nikon D50, Ikelite housing.

Below that by Lester Knudsen with a Nikon D80, Subal housing with TTL circuitry, Ikelite digital TTL cord.

At the bottom are images are by Jay Srenger using a new Olympus Evolt 330, Ikelite housing.

When TTL works, as it does here, the light on the exposure slate will be close to the same in each of the exposure brackets, as that is contributed by the regulated strobe light. The background light density will change according to the various apertures and the ambient light on the scene.