If you landed here, it means that you are ready for the next step in underwater photography, and boy what a huge step it is!
For those who still don’t appreciate the importance of an underwater strobe for your photos, read this. To sum it up – Strobes are the reason awesome underwater photos are so awesome!
In this post we’ve summarized all the information you need to know about choosing an underwater strobe, as well as the best underwater strobe options in the market. We’ve also included info on discontinued legacy strobes, in case you find a good deal on a used strobe on eBay.
If you prefer, you can skip the technical mumbo jumbo and go straight to the underwater strobe options.
* We regularly update this article to include every new strobe in the market! The last update was on January 2020.
Before Choosing a Strobe
Prior to choosing a specific strobe (or two) out of the many options out there, the first thing you need to ask yourself is which camera & housing you are using.
The type of camera, housing, trigger options will narrow down the options for a strobe due to compatibility issues and allow you to find your strobe easily. For example – Ikelite TTL strobes can only be used on TTL with Ikelite TTL housings. (As of recently, new Aquatica housings as well).
Another thing you should ask yourself is what do you intend to shoot. You might need more power to light up wide angle shots from a distance, or 2 strobes if you are shooting fisheye and want to get full coverage. If you plan on shooting wrecks, you may want to place your strobes inside the wreck and trigger them as slaves. All theses are things to consider…
Of course, another important consideration is budget. There are strobes ranging from $99 to $1200. You may not necessarily need the best out there, but rather the best FOR YOU.
Terminology
Before we start going through the options, lets go over some basic terms to help you better understand the features of each strobe. (Already familiar with these terms? Skip to strobe options)
Strobe or Flash
Lets get this off the table – Strobe = Flash! These two terms mean exactly the same and they are words that define an electronic unit which emits a large amount of light in a very short amount of time. For some reason the term “strobe” has been used more for underwater flash units and studio units because it sounds fancier, while the word flash is reserved for the camera’s internal flash and for external hot-shoe flash units. We will use the term “Strobe” for the underwater flash unit and “Internal/On-Camera/Pop-up Flash” for the on-camera flash unit.
Guide Number
The Guide Number (sometimes noted as GN) is quite simply the power output of the strobe. The higher the number – the stronger the strobe. It is defined as GN = Subject Distance from Flash Source x f/Stop which achieves good exposure on the subject, and is usually measured at ISO 100, on land.
That can be slightly confusing but if you think about it for a bit, it makes sense. To measure it, the manufacturer would set the ISO to 100, put a subject at a known distance (10ft for example) and change the aperture until the subject is well lit (Let’s say f/11). Then he will multiply the f/stop by distance to get 10×11 = 110 GN [feet] = 33 GN [meter].
Note that guide numbers can be measured in Meters or in Feet, so make sure you have the same units when comparing two strobes.
Underwater there is no real way of determining GN since the visibility changes significantly which directly affects the reach of the strobe.
Beam Angle
This is quite simple – the spread of light emitted from the strobe. Usually 80-120 degrees in a circular / oval pattern, and increases by 10-40 degrees when using a diffuser.
Color Temperature
Measured in Kelvin and similar to the numbers you know from WB or from light bulbs. Underwater strobes vary between 4300K and 5600K while most are around 5400K-5500K. The important and confusing thing to understand here is that this will basically determine the color of the element which are not lit by the strobe (?!?). Why is that? Because white balance will most likely be adjusted (either manually or automatically) according to the lit subjects to show them in the most natural way, but because WB affects the whole frame, the unlit elements in the background will vary in color according to the adjustment made (the strobe used), while the lit subjects would be the same.
Confused? Don’t worry about it. Most photographers don’t really pay attention to this and still get amazing photos 
For more advanced shooters who want to experiment with this, try putting blue or orange gels on your strobe to change the hue of the background. Ask me about this if you want to learn more!
Recycle Time / Rate
This is one of the most important features. It determines how fast the strobe regenerates for a second shot. It will be measured in seconds and assume full power output was used.
If you don’t want to meet a shark up close and get one well-lit photo among 5-7 dark ones, pay attention to the recycle time!
Naturally when using a lower output, every strobe will recycle faster. Another thing to consider is that when triggering optically, you are limited by your internal flash recycle rate which is usually slower than the strobe at full power.
Helpful Tip:
Use the strobe on manual and trigger it using the lowest setting on the internal flash to enjoy better recycle rates.
Target / Focus Light
This feature which either exist or doesn’t exist in strobes, can come in very handy. It’s basically a low power LED light which helps you to see where the strobe is pointing at, helps the camera focus and can even be used as a secondary dive light at night. It will usually go off when the strobe fires to avoid modifying the final lighting in the image.
Triggering
Every strobe needs a trigger. A method to signal the strobe that it should go off at that moment.
Generally there are two types of triggers – Electrical or Optical. It’s important to understand that one is not better than the other. There are pros and cons to each method.
Electrical Triggering
Electrical triggering requires and actual hard-wired connection between the strobe and the camera, in which an electrical signal can transfer. This causes two major limitations:
1. The camera must have a hot-shoe. Most compacts don’t.
2. Two additional O-rings are needed to keep the connectors dry – thus creating more risk of flooding.
However, this method is great for saving battery life on your camera, since the internal strobe does not need to operate and it also means you can get very accurate exposure using true TTL. This method is mainly used for DSLR’s or high-end compacts in Ikelite & Aquatica TTL housings.
Optical Triggering
There are two types of optical triggering:
1. Slave trigger – where the sensor receives a signal from the surroundings and fires according to that.
2. Fiber optic cable – the sensor is “fed” directly with a focused beam of light through a fiber optic cable which transfers light from the master flash.
Fiber optics is the most preferred method between the two, since it is clean, accurate and reliable.
Optical triggering – Cons:
1. Wasting battery life by firing the on-camera flash just as a trigger.
2. Slower recycle time limited by the internal flash.
Optical triggering – Pros:
1. Simple mechanism, no additional openings in the housing – less risk of flood, easier to fix if there is a malfunction.
2. Works reliably cross-brand. Light is light so the strobes don’t really care which housing/camera you use. (aside from different methods of pre-flash, which are mostly taken care of on the strobe).
Using a slave trigger without a fiber optic cable results in the internal flash being part of the lighting sources, which creates backscatter and uneven lighting. It is also less reliable and may fail to fire under certain conditions.
Strobe Options (Updated January 2020)
Inon S-2000
MSRP: US$479
The Good:
- Ultra compact.
- Reliable TTL.
The Bad:
- Small and confusing controls.
- Special connector needed.
The Good-To-Know:
- The Inon S2000 features a unique mirror adapter which improves the reception of the slave sensor significantly making it more reliable when used without a fiber optic cable.
- Inon offers snoots which fit the S2000 for creative lighting options.
- Mounts are not included. You need to get them separately.
- The S2000 is a direct competitor with the YS-01. Advantages of the S2000 are smaller size, snoot options, sturdy build.
Inon Z-240
MSRP: US$799
Discontinued as of July 2017 and replaced with the Z-330! See below.
The Good:
- Even circular beam thanks to dual flash bulbs.
- Built-in focus light.
The Bad:
- Heavy and bulky.
The Good-To-Know:
- Mounts are not included. You need to get them separately.
Inon Z-330
MSRP: US$699
The Good:
- Even 110 degree circular beam thanks to dual flash bulbs.
- Built-in focus light.
- Strongest strobe in the market – GN33.
The Bad:
- Heavy and bulky.
- Mount required, not included.
The Good-To-Know:
- The Z-330 includes a great rotating light shade to prevent backscatter even when the strobe is closer to the camera.
- Unique warm dome diffusers available (not included) for creative lighting options.
Inon D-2000
MSRP: US$669
Discontinued as of October 2017 and will be replaced with a new version soon! Stay tuned!
The Good:
- Even circular beam thanks to dual flash bulbs.
- Built-in focus light.
The Bad:
- No Sync Cord connection.
The Good-To-Know:
- Basically the same strobe as the Z-240, but triggers optically only and slightly weaker output.
- Mounts are not included. You need to get them separately.
Inon D-200
MSRP: US$500
New strobe – Released September 2018!
The Good:
- Even circular beam thanks to dual flash bulbs.
- Built-in focus light.
- Dome lens produces 110 degree beam without a diffuser.
The Bad:
- Heavy and bulky.
- Mount required, not included.
- Fiber optic only, unlike Z-330.
The Good-To-Know:
- The D-200 includes a great rotating light shade to prevent backscatter even when the strobe is closer to the camera.
- Unique warm dome diffusers available (not included) for creative lighting options.
Sea & Sea YS-01
MSRP: US$429.95
SOLIS MSRP: US$449.95
UPDATE 2020: YS-01 replaced with YS-01 Solis. Main changes are upgrade to DS-TTL II, redesign and improved performance.
The Good:
- Most popular strobe in the market.
- Strong and affordable.
- Built-in target light.
The Bad:
- Larger than the S2000.
The Good-To-Know:
- The YS-01 is a direct competitor for the S2000. See the comparison between them HERE. Advantages on the S2000 – simpler controls, target light.
Sea & Sea YS-03
MSRP: US$429.95 (Full package including tray, arm, cable & strobe)
UPDATE 2020: YS-03 replaced with YS-03 Solis. Main changes are upgrade to DS-TTL II, redesign and improved performance. The bundle includes an improved tray and arm.
The Good:
- Very affordable. Same light output as the YS-01 but about $80 less and comes with a tray, flex arm and fiber optic cable!
- Very reliable TTL mechanism. Perfect light output with every shot.
The Bad:
- TTL only. No manual settings.
- No built in target light.
The Good-To-Know:
- The fully automatic YS-03 replaced the fully manual YS-02. Apparently people prefer setting the strobe on Auto.
- In 2020 the YS-03 Solis replaced the original YS-03.
Sea & Sea YS-D1
MSRP: US$699.95
Discontinued as of July 2015 and replaced with the YS-D2! See below.
The Good:
- Strong power output.
- Great battery life.
- Exposure compensation on TTL.
- Built in target light.
The Bad:
- Heavier and bulkier than the YS-01.
The Good-To-Know:
- You can get this cool strobe cover for your YS-D1 to protect it (and make it look a lot cooler!).
- This is the most popular strobe for DSLR users underwater.
Sea & Sea YS-D2J
* New updated version of the YS-D2 – Made in Japan! Overheating issues fixed!
MSRP: US$689.95
The Good:
- Strong power output.
- Great battery life.
- Exposure compensation on TTL.
- Built in dual powered target light with option for red filter.
- New and improved controls preventing accidental mode switching,
The Bad:
- Heavier and bulkier than the YS-01.
The Good-To-Know:
- The same cool strobe cover fits the YS-D2 as well!
- This has replaced the YS-D1 as the most popular strobe for DSLR users underwater.
Sea & Sea YS-D3
MSRP: US$849.95
The Good:
- Strong power output – 33GN.
- Lightning fast recycle time.
- Exposure compensation on TTL.
- Extra wide beam angle – 120 deg.
- Strong built in 1000 lumen light
- Easy to mount accessories such as diffuser / snoot.
The Bad:
- Heavier, bulkier and pricier than the YS-01.
The Good-To-Know:
- The YS-D3 can fire before recycling completely, so that you get at least some light instead of nothing at all when firing rapidly.
- The built-in LED light is so powerful, you can easily use it as a dive light!
Sea & Sea YS-250Pro
The YS-250Pro has been discontinued! No successor has been released yet.
MSRP: US$1069.95
The Good:
- Lighting fast recycle time.
- Strong even beam.
- Strong built-in target light.
The Bad:
- Very heavy and bulky.
- No optical TTL. If triggered optically – manual settings only.
The Good-To-Know:
- The YS-250PRO has an audible signal indicating when the strobe is ready to fire again, so you can concentrate on your subject without lifting your head.
Ikelite AF35
MSRP: US$429.95 (Includes tray & arm)
The Good:
- Very affordable. Works with every camera that has a flash.
- No need for fiber optic cable.
- Package includes everything needed – tray, arm, sensor and strobe.
The Bad:
- Works as an optical slave only. Camera flash interferes in shot and creates backscatter.
- Slower recycle time.
- You can’t choose which tray & arm to use.
- Rather narrow beam angle (80 deg or 90 with diffuser).
The Good-To-Know:
- The AF35 is one of the easiest strobes you can get. Simply place your camera on the tray and start shooting. Great for people who don’t want to mess around with too many parts.
Ikelite DS51
MSRP: US$449.95
The Good:
- Ikelite’s most affordable DS Strobe.
- Provides perfect True TTL with compatible Ikelite & Aquatica housings.
The Bad:
- Slow recycle time.
- No optical TTL.
- Narrow beam angle (70 deg or 80 with diffuser).
- Only a few manual output steps.
The Good-To-Know:
- The DS51 is best purchased with a package including arm and cable – With Flex Arm or With Ball & Joint Arm.
Ikelite DS160
MSRP: US$799
The Good:
- Very strong output.
- Warmer color output than most strobes.
- Amazing fast recycle time thanks to Lithium battery.
- Provides perfect True TTL with compatible Ikelite & Aquatica housings.
- Built-in modeling light.
The Bad:
- Expensive.
- Heavy & bulky.
- TTL only with Ikelite & Aquatica housings.
- Unique battery – if it’s not charged then no alternative.
The Good-To-Know:
- The DS160 is the choice of many professionals mainly due to the fast recycle time, reliability and warm color temperature.
Best when used with Li-Ion batteries, which improve recycle rate and life span.Li-Ion batteries no longer available.
Ikelite DS161
MSRP: US$949
The Good: (Almost identical to DS160)
- Very strong output.
- Warmer color output than most strobes.
- Amazing fast recycle time thanks to Lithium battery.
- Provides perfect True TTL with compatible Ikelite & Aquatica housings.
- Built-in 500 Lumen LED Video light.
The Bad: (Almost identical to DS160)
- Expensive.
- Heavy & bulky.
- TTL only with Ikelite & Aquatica housings.
- Unique battery – if it’s not charged then no alternative.
- LED Light is nice but not actually strong enough for most videos other than real close-ups and macro.
The Good-To-Know:
- The DS161 is exactly the same as the DS160 but with the LED light. Most photographers prefer getting this one since it’s only $150 extra and you get a 500 lumen light included.
Best when used with Li-Ion batteries, which improve recycle rate and life span.Li-Ion batteries no longer available.
Kraken KR-S02 Strobe
MSRP: US$599.95
The Good:
- Strong output – 24 GN.
- Incredible battery life – over 700 cycles on full power.
- LCD screen that can flip as needed.
- Very fast recycle time – 1.5s.
- Threaded bezel allows easy installation of accessories such as snoot, dome, filters etc.
The Bad:
- Fully manual. No TTL or auto mode.
- Fiber optic only. Can’t be used with a sync cord.
The Good-To-Know:
- The KR-S02 ships with a nice padded case and includes knob extensions for those using gloves.
- If you have the Kraken Hydra 5000S+, this strobe uses the exact same battery!
- YS and Ball mount included.
I-Torch Symbiosis
MSRP: US$499.95 ($699.95 for Pro model)
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The Good:
- Two in one! Powerful video light and strobe.
- Fiber optic triggering.
- Auto off feature on video light when strobe fires.
- Great battery life – up to 700 flashes on full power or 1hr of video light.
- Fast recycle time – 2s.
The Bad:
- Bulky and heavy.
- No “real” TTL. Semi-Auto mode works rather well though.
The Good-To-Know:
- Check out the SS-2 model – it’s stronger, and has a neat LCD panel on the back which makes it much easier to set up and control.
- The video light can be upgraded to 4000 lumens! This model includes the SS-2 with 4K lumens.
- Semi-Auto mode works by “learning” the correct power after setting it up once on a subject, then changing strobe power according to distance from the subjects using a proximity sensor. This works great and includes two modes – one for macro and one for wide angle.
I-Torch Symbiosis SS-3
MSRP: US$399.95
The Good:
- Two in one! Powerful video light and strobe.
- Fiber optic triggering.
- Auto off feature on video light when strobe fires.
- Great battery life – up to 700 flashes on full power or 1hr of video light.
- Much more compact than previous symbiosis models.
- Fast recycle time – 2s.
The Bad:
- GN of 20 and lumen rating of 2800, is fairly lower compared to other options in the market.
- No “real” TTL. “TTL Training” mode works rather well though.
The Good-To-Know:
- Semi-Auto mode works by “learning” the correct power after setting it up once on a subject, then changing strobe power according to distance from the subjects using a proximity sensor. This works great and includes two modes – one for macro and one for wide angle.
Backscatter MF-1![]()
MSRP: US$399
The Good:
- Very small – Designed for macro photography!
- Works seamlessly with a snoot. (Snoot bundle available).
- Capable of up to 1400 flashes on a single charge.
- Strong LED light.
The Bad:
- Not very strong – 16GN.
- Dedicate for macro, so not ideal for wide angle.
The Good-To-Know:
- This strobe is often sold as a bundle with an optical snoot.
- The two LED lights ensure easy aiming with the snoot attached.
Retra![Retra Underwater Strobe]()
MSRP: US$840
The Good:
- Powerful output – 30GN
- Fiber optic and sync cord triggering.
- Choice between S&S 5 pin, S6, N5 and Ikelite 5 pin connectors.
- Optical connector compatible with both Inon and Sea & Sea.
- Fast recycle time – 1.7s
- Faster recycle time – 0.8s with additional battery compartment (sold separate)
- Rated down to 100m / 330ft!
- Plenty of cool accessories available.
The Bad:
- Bulky and heavy.
- New in the market.
- Pricier than other strobes.
The Good-To-Know:
- You can get the additional battery compartment, to pack 8 batteries at a time, for faster recycle time (0.8s) and more flash cycles per charge.
- Sophisticated snoot available – LSD Ultimate, for creative lighting options.
- World renowned UW photographer Alex Mustard was involved in the early stages of production and highly recommends it.
Sealife Sea Dragon
MSRP: $399.95 (Includes tray & grip)
The Good:
- Sleek design.
- Compatible with the versatile Sealife Flex-Connect arm system.
- Affordable
The Bad:
- Very slow recycle time (5 sec on full power)
- Using with the tray included without additional arm segments might create backscatter.
- Inefficient power usage (150 flashes per charge)
The Good-To-Know:
- The Flex-Connect arm system is incredibly fun and easy to use. You can mix and match all Sealife gear with them and easily disassemble for travel.
- The package also includes a nifty travel case.
Fantasea Nano Flash / Intova PX-21
MSRP: $119.95
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The Good:
- Tiny compact flash unit.
- Very affordable.
- Works with almost every camera.
The Bad:
- Weak.
- Only 3 power levels (min, med, max)
- Enclosed in waterproof case – Danger of flooding.
The Good-To-Know:
- This is basically similar to your on-camera flash, but off-camera. You won’t get much power here but you will get better lighting since you can place it on the side of your camera and prevent backscatter while getting more flattering lighting on you subject.
Olympus UFL-3
MSRP: $499.99
The Good:
- See YS-01. This is basically a rebranded version of that strobe.
- Compatible with Olympus Wireless RC flash system which allows higher sync speeds with Olympus cameras.
The Bad:
- See YS-01. This is basically a rebranded version of that strobe.
- More expensive than the YS-01.
The Good-To-Know:
- If you don’t have an Olympus camera, just get the YS-01. If you do, consider getting this one.
UltraMax UXDS-3
MSRP: $349.95 (With tray, arm, cable and travel bag)
The Good:
- Very affordable.
- Easy to use.
- Battery chamber is permanently isolated from electronics.
- Compatible with all camera models.
The Bad:
- Heavy.
- Few power modes.
- Slow recycle time.
The Good-To-Know:
- Simple and useful workhorse.
That’s it. If you still need more info and you’re struggling to decide which strobe to get, simply Contact Us and we will gladly help you out!
News and Updates:
Aug 2015 – YS-D2 replaces the YS-D1!
Oct 2015 – As of now, you can get true TTL with Ikelite strobes (DS51/DS160/DS161) on Aquatica housings as well, either using an Ikelite 4301 or 4302 TTL converter for Nikon or the internal Ikelite TTL circuitry on Canon housing (Aquatica A7D Mk II and A5Dsr housing).
July 2016 – I-Torch Symbiosis released!
Sep 2016 – New Ikelite strobe packages available!
Aug 2017 – Retra strobe released!
Oct 2017 – YS-D2J replaces the YS-D2!
Jan 2018 – Inon Z-330 is here! Replaces Inon Z-240.
Sep 2018 – Inon D-200 released.
Nov 2019 – Backscatter MF-1 released.
Dec 2019 – Kraken KR-S02 Strobe released.
Jan 2020 – YS-01 Solis / YS-03 Solis / YS-D3 released.
The post Best Strobe for Underwater – The Ultimate Strobe Guide appeared first on Underwater Cameras Blog by Mozaik.