ABOUT THIS VIDEO I was trying to coordinate shooting this cenote video with the release of the Canon 5D III. As delivery dates stalled, I kept my original bookings and shot a few days with the Canon 5D II. Within a week of my return, we received an early release of a Canon 5D III camera body. My service manager Scott and I spent a morning hacking a Mark II Aquatica housing to fit the new control layout. It was a pain to do, and it only allowed me to access very basic controls such as shutter speed, aperture, ISO, and the shutter release which I repogrammed to record in video mode, thanks to a new setting on the Canon 5D III. It was frustrating to shoot with this modified housing and I'm eagerly awaiting production housings. With the help of the good folks at Dive Aventuras in Mexico, I was able rebook a quick return to the cenotes and utilize the high ISO abilities of the Mark III in the pitch black waters of the cenotes. This final edit is composed of 70% Canon 5D III footage and 30% Canon 5D II. The topside intro shots were shot with a GoPro Hero2. CANON 5D MARK III VS. CANON 5D MARK II From an underwater (low light) shooter's perspective the Canon 5D III is serious jump in performance. Like many early DSLR video shooters, I was hoping for raw video capture and perhaps reasonable live focus tracking. However, while the Canon 5D III might not be a $15K camera for $3,500, it's an unbelievable video and still camera for the price. My long term customers and friends know that I've been walking the fence between Nikon and Canon for the last few years for my personal rigs. I shoot all video with Canon 5D II, but also travel with a Nikon D3s for all my still work. The focus speed, frame rate, and low light ability of the Canon 5D II seemed 10 years behind the Nikon D3s. Certainly the next camera I'll be testing underwater is the incredible low light Nikon D4. However, the performance of the Canon 5D III in both stills and video is so exceptional, I might have finally found my ultimate one-camera solution. LOW NOISE AT HIGH ISOs The dramatically improved low noise capability of the Canon 5D III is certainly my favorite feature. When shooting the older Mark II, I find ISO settings above 640 produce very gritty shadows and banding in blue water backgrounds. Even when shooting no higher than ISO 640, the Mark II requires you to be spot on with your white balance and exposure techniques as any adjustment in post production will quickly degrade image quality. Many clips of large rooms in the cenote video were shot at ISO 2500 on the Canon 5D III with exceptional lack of noise. I even made a slight white balance correction to a few of these clips with no visible damage in image quality. This one improved feature is reason enough for me to upgrade to the Canon 5D III. NEW ALL-I VIDEO CODEC The Canon 5D III has an option to shoot in a new video compression format called ALL-I and offers data rates up to 92 Mbps. This is a significant upgrade from the Mark II's 42 Mbps data rate and more fragile compression method. The ALL-I codec compresses each frame individually, which greatly improves issues of moirÃ© - banding artifacts that can typically appear in photographs of repeating patterns such as clothing, feathers, or other textures. The new codec also reduces the amount of computer processing power required to edit, and allows the footage to be more heavily manipulated using color correction and adjustments to brightness during post production. Mark II files needed to be shot perfectly in camera for best results, but the ALL-I files in the Canon 5D III are much more forgiving. The ALL-I files do look a little soft in comparison to the Mark II files. Some early shooters are reporting they feel it necessary to sharpen the files in editing. HDTVs and HD projectors tend to over-sharpen and bump the contrast on the picture. This led 5D Mark II footage on these displays to look over-processed. While Canon 5D III footage can look a little soft on a computer monitor, I find the softer files look more natural when displayed on these HD monitors and home theater projectors. The ALL-I format does present new pros and cons. The files drop right into Final Cut without the need of transcoding to Pro Res 422. This saves a time consuming and hard drive filling step. However, the ALL-I format with its higher data rate inherently eats up more storage space, which will definitely necessitate traveling with larger drives in the field to store all of your raw footage. Also, the ALL-I format does not have thumbnail files which contain shooting metadata. The lack of metadata is only an issue if you like to know what f-stop or ISO was used on a particular clip. Based on my experience, I'll gladly make these trade-offs for the added benefits of ALL-I. GREAT AUTOFOCUS AND FRAME RATE While the video prowess of the Canon 5D II caught everyone off guard, its sluggish focus and the ka-klunk, ka-klunk, ka-klunk of 3.9 frames per second made it difficult and sometimes impossible for fast action work. The Mark III's 6 frames per second now delivers a solid frame rate for action photography. I was most impressed by the Canon 5D III's ability to quickly autofocus in very low light even in live view video mode. With the Mark II, I'd frequently have to attempt a focus capture twice or worse swim out into reasonable light. The Canon 5D III would snap on focus even in the twilight shadows of the cenotes. On the video side of things, the Canon 5D III adds an additional 720/60p frame rate, useful for doing slow motion effects. This is an omission in the 5D Mark II versus all Canon DSLRs that followed. While we're disappointed that the camera doesn't offer full 1080p resolution at this faster frame rate, 720p is certainly better than nothing for being able to slow down our footage. CONCLUDING THOUGHTS On paper, the Canon 5D III may not seem like a revolutionary upgrade, but the improvements that it does make correct some of the most serious shortcomings of the 5D II. There's better ergonomics with a control layout similar to the Canon 7D. The increased frame rate and super fast autofocus alone are worth the upgrade from the 5D Mark II. And while it may be hard to distinguish between the 5D II clips and 5D III clips in the video above, you'll be able to get the shot with the Mark III in conditions where you just simply couldn't pull it off with the 5D Mark II. Other subtle differences like increased ISO performance, reduced noise, increased dynamic range, and much improved video codec help take the Canon 5D III to the next level in image quality for both stills and photo.