Light & Motion Bluefin HD UWA Lens – Field Test


I spent some time in Bali performing comprehensive in-water testing of Light & Motion’s new UWA lens. I was fortunate enough to be able to test the lens in a wide spectrum of conditions while shooting a variety of subjects. It is important to note that this is NOT a technical review where I applied optical testing procedures to verify lens capabilities and limitations. Instead, I went into the field and subjected the lens to real world UW shooting conditions with as much variability as possible. I then captured and exhaustively reviewed the footage on a 1920×1080 monitor evaluating performance and limitations. I used the L&M 80 degree lens as a baseline to compare/contrast with. As there isn’t another UWA lens for the Bluefin HD, I obviously could not perform a comparison of this lens to an “alternative”. Finally, the only other UWA lens for a Z1/FX1 housing that I am familiar with is the Fathoms UWA for the Gates housing. As I have not shot with this lens or reviewed any HD footage produced by this lens, I have no basis to compare or contrast the Bluefin HD UWA with it. So moving on to the review:

Usage conditions included:

  • Depth from 1 meter to 40 meters deep
  • Visibility from 5 meters to 40 meters
  • Time of day from early morning to later afternoon
  • Weather ranging from overcast to brilliant sunshine
  • Distance to subject from 1 cm to 30 meters
  • Subject size from 2 cm to 3 meters
  • Motion of subject from completely stable to fast moving
  • Currents from none to 4 knots
  • Angles of shots (up, down, level, into sun, sun at back, etc)
  • Focus using both manual and auto

After gathering the footage, capturing it and editing it, I was able to draw some firm conclusions regarding the UWA lens. I spent a good deal of time staring at a large HD screen evaluating the quality of the images I captured under all kinds of conditions. The following are my findings.

What I liked:

  • No vignetting – absolutely none…enough said!
  • Image quality – lens delivered sharp images for subjects reasonably close to the lens
  • FOV – very good, estimate 105 to 110 degrees
  • DOF –quite good, single shots yielded sharp images of subject both near and far
  • Lens size – compact and not bulky
  • Lens construction –solid and well constructed
  • No lens coating – means far less likelihood of scratches or general wear-and-tear
  • Price – MSRP of USD 3K (vs.USD 4.5K for Fathoms lens for Gates)

What I didn’t like:

  • Edge distortion –observable distortion (>5%) on the edges of the lens for medium and long distance shots (close wide shots were fine)
  • Zoom through –zoom through on the lens estimated to be 70% and not really useful for macro related shooting
  • No lens coating – increased amount of lens flare with internal element/lens reflection in bright light
  • Lens weight/buoyancy – Bluefin housing is an amazingly well balanced housing with exceptional trim capabilities. The lens makes it very nose-heavy.

Indifferent:

  • Light fall off on edges – pretty good, better than my 80 degree lens

General findings:

After testing the lens thoroughly (but admittedly for a limited period of time), I find the lens delivers a combination of both great and OK footage. In the right conditions and with the shot set up correctly, the lens delivers exceptional results…a big step above the 80 lens. If conditions and/or shot set up are otherwise, the results are not as exciting.

At its best: Reasonable to good lighting, subject close to the lens and filling the frame (large pelagic, coral head, etc) with little motion occurring on the edges of the lens:

-The lens delivers stunning wide images of the subject

At its worst: Fair or poor visibility, medium to long distance from subjects, lots of motion occurring on edges of lens or (camera tracking quickly):

-The lens delivers good image of subject in most of frame but with observable distortion in subject and/or background along edges of lens.

Given the above, the UWA really excels over the 80 lens for up close wide angle shooting. For general purpose shooting, the 80 lens will be more versatile (general reefscape shots, schools of fish swimming by, divers on the reef, etc) or the flat port for macro of course. The primary reason for this is that the 80 delivers a sharper image edge to edge for medium and distant wide angle shots where FOV is less important. The UWA lens is a great option for serious shooters who have the knowledge and discipline to use the lens correctly. This is not an all purpose lens like the 80 lens. It is a lens with a purpose and would be used as part of the professional’s toolset of lenses.

  • UWA for close wide angle shots
  • 80 lens for med wide angle, close up and “medium” macro
  • Flat port for macro and super macro

Things I would like to see from L&M to support the UWA lens:

Buoyancy and trim – provide an out-of-the-box solution that that accompanies the lens that enables customers to enjoy the benefits of the excellent trim and neutral buoyancy of the housing, yet still preserves the “clean” and professional look and feel for which Light and Motion is famous.

Final Considerations:

Light and Motion has set the bar in the industry with the Bluefin HD housing. When you consider the performance, construction and ergonomics, it stands above the competition. The 80 degree lens is an exceptional performer for a flat lens and delivers great results for both wide and close shooting. The available flip macro extends its capabilities into the macro range.

The UWA lens is a specific purpose lens, much like the flat port for macro. I think of the UWA as similar to the 10.5 lens for digital still shooters. A great wide lens that yields stunning results when applied correctly in certain conditions (much like a 10.5, both excel in close super-wide shooting scenarios). The 80 lens fulfills the general purpose shooting requirements, while the UWA address close wide angle and the flat port, macro. This is a lens for serious shooters, professionals who are diving to get the shot, and have chosen subjects that fit well with the lens’s characteristics. The UWA is NOT a replacement for the 80 lens, but should be used in conjunction with it. In reality, a serious shooter needs to own all three lenses to get full coverage.

Though I recognize that the lens has certain limitations, I am happy I purchased the lens. For my purposes, the benefits the lens out-way any of the limitations listed above. I am a wide angle shooter at heart and there is no substitute for that super close wide perspective. The details, crispness and “close proximity” feeling that the lens delivers are exciting. Edge distortion is a disappointment and an issue that I must manage. If one sets the shot up “correctly” keeping this limitation in mind, the “apparent” distortion is minimal. Lack of full zoom through is not a real issue for me because I don’t zoom much when shooting wide (kinda defeats the purpose of “wide” shots” IMO). In addition, I have not seen UWA macro footage (lenses wider than 100 degrees) that interests me. If I am shooting macro, I want quality macro footage and will take the necessary steps to shoot it properly (flat port, macro adapter) so I get sharp images with usable DOF in the macro range. A final consideration is that the combined cost of the UWA and the 80 degree lens is about the same as the cost of just the UWA for other housings. Though there is less convenience with having 2 lenses instead of one, one gets the benefit or greater macro range and lens redundancy (one has a back up lens).

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