By Gary Burns
For the past several years, I have been using an electrical sync cord and DL5 TTL Converter with my Canon R5 camera and, typically, the Canon RF 14-35mm F/4 lens. My strobes are the Ikelite DS161 legacy model, which are extremely reliable and have supported me well throughout my weekly diving campaigns in California during the past 8 years. My 200DL underwater housing has always been reliable and has produced a wonderful portfolio of the underwater world.
But on a recent trip to Belize I went fiber optic. My goal was to provide a subjective opinion of the new Ecko Fiber and RC165 strobes, by evaluating their performance compared to my original wired configuration.
Gary shooting with dual RC165 strobes. The new RC165 features native fiber optic support in place of an electrical bulkhead. © Scott Shew
Updating the Underwater Housing
For this adventure, I replaced the electrical bulkhead and hotshoe on my housing with the new Canon TTL Fiber Optic Transmitter. The Ecko Fiber and RC165 strobes are fiber optic compatible out of the box, they attach directly to the transmitter using fiber optic cords.
RC165 Strobes have the ideal color temperature for natural colors in the turtle and corals with a deep blue-water background.
The fiber optic TTL transmitter attached to the housing is powered by two CR2032 coin cell batteries. It is important to ensure and remember that the internal battery case was switched on prior to closing the housing. The transmitter mounts to the top of the housing and has two ports for fiber optic cord attachment. The connection is sturdy and holds the optical cables tight throughout the dive profile. While I could have used my old DS161 strobes optically by adding the RC2 Receiver, I appreciated that the new strobes had this functionality built-in and the fiber optic cords attach directly to the undersides of the strobes.
Dual Ecko strobes with TTL exposure perfectly light a wide reef scene.
Physical Features
Both of the new fiber optic strobes feature a standard 1" (2.5cm) diameter ball mount, that works directly with the standard strobe arms.
The RC165 strobe utilizes the standard legacy battery which can be charged with the same power adapter I already had from my older DS161 strobes. The controls on the strobe are familiar, and I particularly like the updated switch knobs that are beefier and easier to turn. It's extremely well engineered, based on a well-proven engineering design and in-service performance. I liked that the strobe was a bit smaller than my original DS161, and has a solid and sleek front. The redesigned front actually makes the strobe beam quite a bit wider than my old strobe.
RC165 Strobes in TTL mode are capable of more dramatic lighting by adjusting the positioning of your strobes in relation to the subject.
The new, smaller Ecko strobes are a lightweight, more cost effective, robust design that includes a removable dome diffuser. The back of the Ecko strobe features TTL and manual controls that are easy to use on land and as well as in the water. The Ecko strobes use four AA-cell batteries. You can use alkaline though I prefer the rechargeable Eneloop Pro. The batteries are easy to install as per the orientation specified on the inside of the battery compartment. The batteries can simply be changed in the field or on the boat. Based on a two dive per day profile I did not have to change the batteries during a day of diving, having shot approximately 150 shots per dive.
The compact size of Ecko Fiber strobes makes them easy to position when your subject is very close to the front of your port.
First Impressions // RC165
My first dive was setup with the professional grade RC165 strobes. My first impression underwater was that the system was easy to maneuver and lighter than the wired system that I am familiar with; no more external synchronization connector and larger telephone type cables, just two optical cables.
RC165 strobes in TTL mode easily handle an approaching subject without blowing out the highlights on the shark's reflective underside.
During the dive profile I was able to manipulate the RC165 strobe positions with ease, from the wide orientation to close up. The typical strobe positioning I have adopted for wide angle is turned outwards about 15º from a facing forward position, so that the strobe beams overlap approximately in the center of the lens. This is not always the case, but it’s a good starting position for the strobes.
Using the RC165 strobes in TTL mode gives you access to a much wider range of power levels- including very low light levels needed for close focus wide angle shots where the subject is inches from your dome.
The lighting performance of the RC165 strobes provided excellent coverage at many aperture settings. I appreciated the extra angle of coverage due to the redesigned front. During many of the dives, I adjusted the aperture from f/11 to f/22 for larger depth of field for close up and opening the lens aperture to f/4 for sharks in midwater over the coral walls in lower light situations.
It's easy to shoot day for night with very small apertures when you have the power of the RC165 strobes.
First Impressions // Ecko Fiber
The Ecko Fiber strobe was easy to install onto the system geometry with the R5 housing and the optical cable installation is identical for both strobe setups. Immediately, I noticed the smaller, compact, lighter weight profile in comparison to the RC165 strobes.
In the water the Ecko strobe configuration with the smaller profile helps reduces the hydro dynamic drag and it is very easy to maneuver the strobes for different lighting conditions. Subject lighting closeup was excellent and I found that the TTL was responsive an accurate at all aperture settings. The included dome diffusers spread the strobe beams very evenly over 140º of coverage, which renders seamlessly in wide angle scenes.
Ecko strobes handle more than just macro- they can easily take on a wide angle reef scene. As you can see here, it's a misconception that TTL only works when the subject is in the center of the frame.
For subjects at a distance, I did notice the difference in power in comparison to the RC165 strobe, which is the only real trade-off that I could witness between the two configurations of strobes. The Ecko strobes do need about a second to recycle between shots, compared to the RC165 which is instantaneous. But I found I didn't notice any lag or changes to my shooting, because I am typically recomposing or adjusting settings in between shots. The Ecko strobes were able to provide multiple shots without any lighting degradation.
These series of dives in Belize gave the opportunity to test the new Ecko Fiber strobes in differing lighting conditions. The strobes performed flawlessly and provided state of the art lighting conditions and exposure to capture still and fast-moving sea creatures.
Conclusion
The resulting color balance of the images was excellent close up using the Ecko and RC165 strobes, when using “Auto" white balance setting in the camera setup. The image quality I have obtained after editing are well balanced, even though the visibility and particulate in the water wasn’t ideal.
Though I typically shoot pro-grade strobes, the Ecko strobe have a place in my gear bag for both macro and all-around shooting. Fiber optic cords make it easy to switch strobes between dives.
Based on experiences using the wired or optical system setups, the RC165 strobes provide a ultra-wide range of lighting coverage for the underwater environment. The RC165 strobes are well seasoned and provide the amateur or professional photographer the tools required to capture the undersea life or underwater landscape images at the highest quality.
With the Ecko I was surprised by the amount of power in such a small strobe. The new lighter, cost-effective design enhances the travel experience when carrying underwater equipment to far destinations. Based on my experiences with the new Ecko strobes, I am really impressed by its quality, compact design and my resulting images captured during our underwater adventures.
Gary with dual Ecko Fiber strobes on his Canon R5 underwater housing. © Scott Shew
After shooting fiber optic TTL and experiencing the ease of transitioning between the strobes, I can definitely see a place for each of these strobes in my gear bag in the future.
Equipment Used
Ecko Fiber Strobe # 40101
RC165 Strobe # 40116US (40116EU / 40116AU / 40116UK depending on charger plug)
TT5 Canon TTL Fiber Optic Transmitter for DL and DLM Underwater Housings # 44701
200DL Underwater Housing for Canon EOS R5 # 71764
Additional Viewing
RC165 Strobe Features // Smaller, Wider, Fiber Optic
Setting Up Your Ecko // Ecko Fiber/DS Strobe Assembly [VIDEO]
Problem Solved: Ecko Fiber TTL Results with OM System TG-7
Josh Blank's Lighting Setup 2025 // Manual Fiber Optic Transmitter [VIDEO]
TT5 Canon TTL Fiber Optics Transmitter Review & Results
Ambassador Gary Burns is an underwater photographer and Senior Engineering Fellow at Safran Engines in France. His work discipline has taken him from his homeland of the UK to Canada and the USA to work with leading aerospace engineering teams, developing corporate aircraft, cabin interiors, and state of the art aircraft engine power plants. During his working career he was involved in development flight testing, which is very much like scuba diving. The discipline requires very dedicated rules, which provides unique personal experiences that drives curiosity, a sense of adventure and creativity. Since then his professional aerospace career has taken him to Southern California where he dove on a regular basis in the Channel Islands off Santa Barbara and Catalina. The protected dive sanctuaries and Pacific Ocean kelp forests provide the chance to sharpen photography skills from wide-angle to close-up macro with a wealth of sea life and sunlight beaming through kelp. Read more...
