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The author would like to thank Retra Underwater Technology for providing the pair of Retra Flash Pro Max strobes used in this review.
 

Full disclosure: Since Retra first released the original Retra Flash back in 2017, I have owned a pair. They have been a workhorse strobe for me, performing without any hiccups in environments from the frigid waters of Silfra Fissure in Iceland to the warm waters of Indonesia. While I love those original strobes—and plan to use them until they give up the ghost—there are aspects of them that could be better.

I was fortunate enough to be able to try the Retra Flash Pro before it was first released in 2018, and in terms of light quality and ergonomics, it left the already-great originals in the dust. However, the Flash Pro sucked the juice out of batteries very quickly and to get the most out of it, the additional Supercharger was a necessity, adding extra bulk and expense.

Then, in 2021, came the Flash Pro X, alongside the Flash Prime X and Supercharger X battery pack, none of which I used but which promised further improvements. Two years later, in 2023, Retra released the fourth iteration of its strobe series, including the Flash Pro Max. The newest-generation strobe has come a very long way from those “ancient” originals. For the past few months, I have been able to shoot the new model around Florida. While the weather gods seem to know exactly when I’m doing an important review and toss as much nastiness as they can at me, I was still able to get out for some nice days in the field and to get a feel for the strobes in the real world. Has Retra managed to make the perfect all-around strobe? This is not an inexpensive piece of kit, so does the Retra Flash Pro Max justify its substantial price tag? Let's find out!
 

Silver dollar plant, Florida, USA. The Retra Flash Pro Max provides a gorgeous quality of light in a compact package (Sony a9, Nikonos RS 13mm f/1.8 Fisheye lens, Seafrogs housing, dual Retra Flash Pro Max strobes, Retra Wide Angle Diffusers, f/8, 1/100s, ISO 200)

The original Retra Flash had great ergonomics, and the Flash Pro Max has just about perfected them. Retra has put a lot of thought into the physical design of their new strobe. The original was beautifully made and the large dials were easy to adjust even with thick coldwater gloves. The Flash Pro Max has refined these dials and made them even nicer to use and adjust.

The updated dials have been lengthened and stippled for easier and better gripping, and cleverly, Retra has made each dial a different length so you know which one you are changing without looking at the strobe. The longer dial is the one for changing power levels, while the shorter one is for your different strobe settings, which you will likely be changing less during a dive, hence the shorter length. Each power setting has a hard stop, which I love, as you know exactly where the dial is set and you don’t have to worry about accidentally knocking the power up or down.

Retra has kept the same bayonet mount on the front of the strobe to be able to take advantage of all their lighting accessories, whether it be their various diffusers, or their much-loved snoot, the Light Shaping Device (LSD). Keep in mind, though, if you are upgrading from the original flash, the snoot will be best served by getting the updated mounting module. The differently shaped flash tubes will not perform the same way behind the snoot, so while the Flash Pro Max will work with the mounting module made for the original strobe, the light transmission won’t be as good. Out of the box, the Flash Pro Max is ready to shoot via fiber-optic cables. It does not feature an electronic bulkhead, so those wishing to connect them via electrical cables will need to purchase the Retra E-Opto sync cord converter for each strobe.
 

A lined seahorse hiding in plain sight on a rubble patch, Florida, USA. The wide, soft, forgiving beam of the Retra Flash Pro Max makes close-focus wide-angle lighting a breeze (Sony a9, Sony 90mm f/2.8 Macro lens, Seafrogs housing, Nauticam EMWL, dual Retra Flash Pro Max strobes, Retra Wide Angle Diffusers, f/10, 1/10s, ISO 500)
 

The Flash Pro Max features a small LCD screen on the rear of the strobe that shows both power setting, strobe setting, and battery level. Admittedly, I did not look at this screen much, but it is definitely useful to see power levels quickly if you are shooting in the dark or to check battery levels if you have been in the water for a long day. One quirk to be aware of: When you turn the Flash Pro Max on, you cannot just turn it right to the “On” setting. First, you must turn it to “Test/Batt”, pause, let the strobe activate, and then turn it to “On.” This caught me off guard initially when I first tried to turn on the strobe by going straight to “On.” It doesn't take long to get used to but should be mentioned to save any readers a few moments of panic that their brand new strobe isn't working!

Another innovation that is Retra's alone is a built-in leak alarm. Almost every underwater housing these days has some sort of leak detection, but Retra is the only one who has put such a thing into a strobe. If water breaches the battery compartment, the alarm will alert you straight away.

Perhaps Retra’s cleverest trick is making the strobes updatable and upgradable via firmware updates. Using the Retra App, you can add new features, eliminate bugs, and troubleshoot issues from anywhere with a Wi-Fi connection. Similar to how camera manufacturers roll out firmware updates for cameras, Retra has give shooters the ability to do the same with their strobe. This is quite remarkable, and if I’m not mistaken, it is the only strobe on the market that allows you to do this. The app also provides data points such as the number of times an individual strobe has been triggered.
 

Florida redbelly turtle, Florida, USA. The Flash Pro Max gives a beautifully soft and diffused light that is easy to balance with ambient natural light (Sony a9, Sony 90mm f/2.8 Macro lens, Seafrogs housing, Nauticam EMWL, dual Retra Flash Pro Max strobes, Retra Wide Angle Diffusers, f/10, 1/50s, ISO 320)

The Flash Pro Max features 140 Watt-seconds of power, the highest output of Retra’s latest strobe series. While this isn't class leading and falls short of strobes like the Ikelite DS230, Kraken KS160 and Seacam 160D, the Flash Pro Max is powerful enough for just about every situation, including big animals, wrecks and scenics.

It is clearly designed as a wide-angle strobe. While it can, of course, be used to create world-class macro images, it is very much geared towards wide-angle shooting, so having lots of power is a good thing. For the subjects I was shooting, I rarely found myself going above half power and usually lived around 1/4 power.
 

Even shooting a subject backlit by the sun, the Flash Pro Max at 50% power had no issues lighting the prow of this boat (Canon EOS R100, Canon RF 15–30mm f/4.5–6.3 lens, Ikelite housing, dual Retra Flash Pro Max strobes, f/13, 1/200s, ISO 100)
 

I will touch on this in every strobe review I do, just to make sure it is not missed: As you increase power towards a strobe’s maximum, the light from the flash tends to become harsher and less pleasing. That means, if you have a strobe with lots of power, you can use a lower proportion of the overall power while still getting lots of light. That equates to nice light at higher power levels.

The Flash Pro Max is powered by four AA batteries (or eight with the Booster battery pack). The battery compartment has been redesigned and is now double O-ring sealed with a large, grippy dial to thread and unthread the cap. This is a big improvement over the originals.
 

Florida manatees, Florida, USA. I was set up to photograph a turtle when these manatees surprised me by swimming up to me unexpectedly. The strobes were not positioned ideally but the forgiving beam still gave me an acceptably lit image (Sony a9, Sony 90mm f/2.8 Macro lens, Seafrogs housing, Nauticam EMWL, dual Retra Flash Pro Max strobes, Retra Wide Angle Diffusers, f/10, 1/30s, ISO 400)
 

A bane of Retra strobes in the past has been power consumption. They chewed through batteries and while the original was more forgiving, the previous iterations of the Flash Pros tended to require the Superchargers to get through a few dives. The Flash Pro Max uses power more efficiently and while it does still allow you to use eight AA battieres with the redesigned Supercharger (now called the Booster) if you choose to, it is no longer a necessity. I've gone through entire days on a set of batteries without having to worry about the strobes dying on me.

What the extra battery pack does provide that can be beneficial is faster recycle times. Strobes with large battery packs like the Ikelite DS230 or Kraken KS160 generally have an advantage over AA-powered strobes with regards to recycle time. This is where the Booster can level the playing field somewhat, and at lower power settings, the Flash Pro Max is limited more by flash trigger recycle capability than strobe recycle time.
 

Suwannee cooter, Florida, USA. Shooting into the sun, the Flash Pro Max provides plenty of power to comfortably light the subject (Sony a9, Nikonos RS 13mm f/1.8 Fisheye lens, Seafrogs housing, dual Retra Flash Pro Max strobes, f/10, 1/100s, ISO 250)

While Retra has created a great all-around strobe, the light quality is really what this strobe is all about. The original strobe created beautiful light despite the rectangular flash tube and being a first-generation product. It’s subjective, of course, but for me, the Flash Pro Max offers the best light quality of any strobe I’ve used, and that includes besting the Kraken KS160 and the Ikelite DS230—both stellar strobes.

The round flash tube is tailor made for a wide, soft, forgiving beam and Retra has frosted the glass on the strobe face for better diffusion. I still prefer to use the wide-angle diffuser on the Flash Pro Max, as I find they just add a tiny bit more diffusion, which is helpful for close-focus wide angle and while photographing reflective subjects, but I also did shoot them without the diffusers and they still produce a top-notch beam.

While the original Retra Flash is arguably better macro strobe, due in large part to the smaller flash tube and harsher light (therefore being easier to shape), the Flash Pro Max is no slouch and Retra’s vaunted LSD and other light modifiers like reduction rings and reflectors make the strobe a very versatile flash. As I touched on earlier, the round flash tube makes this strobe more ideally suited to wide angle, so precise macro lighting will be a little more effort.
 

Striated frogfish, Florida, USA. The bayonet mount on the front of their strobes and their arsenal of light modifiers make the Retra Flash series incredibly modular. Custom-made reduction rings allowed me to dramatically cut down the beam angle here (Sony a9, Nikonos RS 13mm f/1.8 Fisheye lens, Seafrogs housing, dual Retra Flash Pro Max strobes, Kraken Sports NR-1000 dive light, f/11, 1/100s, ISO 100)
 

Lined seahorse, Florida, USA. Like the frogfish above, reduction rings helped control the soft, wide beam and angle it much better to eliminate an unappealing background (Canon EOS R100, Canon RF 100mm f/2.8 Macro lens, Ikelite housing, dual Retra Flash Pro Max strobes, custom-made reduction rings, f/10, 1/200s, ISO 100)

Retra already enjoyed a reputation for creating exceptional lighting tools and the Flash Pro Max carries on that tradition. This is a phenomenal all-around strobe, and easily one of the best strobes I have had the pleasure of shooting. The ergonomics and light quality are top tier, and the ability to update the strobe via firmware is a nice touch.

I feel there are specific instances when I might reach for a bigger, battery pack-powered strobe, but if you are in the market for a strobe that does everything and does it all well, the Retra Flash Pro Max will fit the bill. Beyond my desire for a battery pack instead of AAs, there are really no negatives. (Of course, many people like strobes that run on over-the-counter batteries, so that likely won’t be a problem for lots of shooters.) While the price for a pair of these strobes will make your wallet tear up, if budget is not a major factor, the Retra Flash Pro Max deserves some very serious consideration.
 

A loggerhead musk turtle peering up at me from an underwater garden, with wide, soft light across the frame from the Retra Flash Pro Max, Florida, USA (Sony a9, Nikonos RS 13mm f/1.8 Fisheye lens, Seafrogs housing, dual Retra Flash Pro Max strobes, f/10, 1/200s, ISO 250)
 

About the Reviewer: Matthew Sullivan is a Florida-based wildlife photographer who has been diving since he was 10 years old. He has traveled extensively, visiting well-known dive destinations such as Guadalupe Island, Indonesia and the Philippines, but he also likes to dive closer to home in Florida. When not taking pictures underwater, he can be found trekking mountains, or exploring national parks and rainforests in search of new adventures and wildlife encounters.
 

Retra Flash Pro Max Strobe

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