Retra Flash Underwater First Impressions

First dives with the new Retra Flash
By Matthew Sullivan

Retra UWT is known best for its beautifully constructed optical snoot, which they dubbed the Light Shaping Device. The company created a buzz in early 2017 when it announced production was beginning on their new Retra strobe. I pre-ordered two immediately. Production has been understandably slow as Retra seems to be making sure they put out a product that is top of the line and has been thoroughly thought through. I am still waiting on my own personal pair, but through Bluewater Photo, managed to get a pair early to take for a few test dives. Conditions were far from ideal, but I made do!

Price: $825.00



Purchase the Retra Flash


The new Retra Flash, here fitted with the wide angle diffuser that comes standard with each strobe.



  • 100W/s 
  • GN30 in comparison with two strobes - see comparison here 
  • GN18 (absolute measurement on land) 
  • Recycle time @100%: 2s (4x eneloop pro), 1s (8x eneloop pro) 
  • Number of flash @100%, 0.5Hz: 450x (4x eneloop pro), 900x (8x eneloop pro) 
  • 300 lumen pilot light 
  • Pilot light burn time @100%: 3h (4x eneloop pro), 6h (8x eneloop pro) 
  • 5400K color temperature (4500K with wide angle diffuser) 
  • 110º beam angle 
  • 9 manual exposure levels 
  • S-TTL with +/- 2 F-stop adjustment 
  • Slave mode with smart pre-flash cancellation 
  • 4 level battery indicator for eneloop batteries 
  • Electrical connector options: S&S 5 pin, S6, N5 and Ikelite 5 pin 
  • Inon and Sea&Sea dual compatible optical connector 
  • Length = 120mm 
  • Diameter = 102,5mm



I'm coming from using mainly Inon z240's, S&S D1/D2's/01's, and a few Ikelites here and there. The Retras were promising simplicity, durability, power, and high end functionality. I'd be lying if I said I wasn't skeptical. 


A coldwater gorgonian attached to a piling of the Eureka Oil Rig off Southern California. Not the most exciting of scenes but nice to see the potential of the Retras. Nikon D850, Nauticam Housing, Nikonos 13mm, 2x Retra Flash w/Wide angle diffusers on 1/4 power. 1/15, f5.0, ISO 320


Well, as soon as I unboxed the test pair, I was sold. Not only do the flashes look amazing (and gear aesthetics is obviously the most important aspect of underwater photography!), but they are built like tanks. The aluminum body, the smooth, large dials, the built in mounting ball (removeable via allen key)...everything working together to produce a small, powerful package.

Front of the Retra Flash showing the bulb and the four circles that indicate battery life. The bayonet style wide angle diffuser on the right comes with two small diagrams to show exactly how to mount and lock the diffuser onto the front of the flash.


I personally am not a huge fan of lab tests. I like to know how gear performs in the real world and what features the strobe has that will benefit photographers in the real world. The built in battery indicator on the front is fantastic, and is visible even with the wide angle diffusers in place. It is certainly nice to know how much charge the strobes have left. Speaking of diffusers, the bayonet style attachment of the diffusers onto the front of the flashes is quite nice and assures diffusers can't get knocked off or pulled off accidentally while underwater.

On settings on the left, power settings on the right, pilot light in the middle, fiber optic port bottom right, electric sync port bottom left, battery compartment top.


There are nine power settings on the the back of the strobes, all easily chooseable with the large, smooth dial. The flashes take electronic or fiber optic sync cables (both Inon style mount and S&S style mount), and have corresponding settings based on which you are using. The dial that activates the strobe has several different notations. OFF, ON (the setting to use with electrical sync cables), STTL, SL (the setting to use with fiber optic cables), and SOS. An easily pushable pilot light is centered in the back of the strobe, with multiple power settings. The battery compartment (sealed off from the rest of the strobe) is a screw in/screw off, with perfectly decipherable instructions inside the battery compartment as to how to load the batteries.

For standard fare macro shots, like of this Bluebanded Goby, the Retras put out a soft, diffuse light that spreads nice and evenly. There are several accessories I ordered with my own pair that will allow for more creative lighting but I do not yet have access to them. Nikon D850, Nauticam Housing, Nikon 105mm VR, 2x Retra Flash on 1/8 power w/wide angle diffusers. 1/250, f6.3, ISO 64


Speaking of batteries, over four dives and 500+ shots, I still didn't run out of battery, and that was without using the optional external battery pack. However, when the battery levels start getting low, the Retras did start to not be able to keep up with the 5fps I had been shooting previously. Recycle time normally is instantaneous at half or lower power.

 There is little doubt in my mind that the Retra Flash is a solid alternative to other leading strobes, and I am eagerly awaiting my own pair so I can continue to use them for the foreseeable future. The simplicity, build quality, power, (and of course aesthetics!) make this an enticing strobe in a small package whether macro or wide angle is the main focus of your photography. Next up I will be running a trip in Anilao, Philippines this December! (One spot left on my trip!) Hopefully I can put the strobes and all accessories to good use.

Pre-order the Retra Flash Now

Join Matt in Anilao and try out the Retra Flash

Dual Retra Flashes attached to Nauticam D850 Housing


Matthew Sullivan is an underwater and conservation photographer based out of Los Angeles, CA. For more of his pictures follow him on Instagram.


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