The SEA&SEA YS-D2 strobe is the latest in a line of very popular strobes for underwater photography. Compact, powerful and quick to recycle, the YS-D1 took the dive world by storm. The YS-D2 builds on this success, adding some new features and addressing some of the minor "inconveniences" of the previous model.
We decided to test the new YS-D2 against the YS-D1. Kelli also took two demo YS-D2s to the Sea of Cortez for a week of real world testing. This is what we've found.
Moray eel portrait in the Sea of Cortez. Olmpus OM-D E-M5 Mark II with Olympus 60mm macro lens and dual YS-D2 strobes. Photo: Kelli Dickinson
YS-D2 vs YS-D1 Strobe Power
The SEA&SEA YS-D2 strobe is rated to have the same power as the YS-D1. We tested this in a dark room, firing first one strobe and then the other on manual power from the exact same position. Camera was on a tripod, holding each strobe directly above. You can see in the histogram pics below that both strobes do indeed fire with the same power intensity.
The front of the YS-D2 strobe (left) looks identical to that of the YS-D1 (right).
You can see in the histogram photos above that the YS-D2 power levels at max, half and low power match those of the YS-D1.
Strobe Recycle Time Comparison
We decided to test the recycle time of the SEA&SEA YS-D2 against that of the YS-D1. To do this, I put fully charged Eneloop batteries in each strobe and connected them to an Olympus OM-D E-M5 Mark II via dual sync cord. The sync cord eliminated any consideration of the camera's flash recycling, while manual settings and manual focus ensured the camera would always fire when I pushed the shutter. Both strobes were set manually to full power to ensure the capacitors fully recycled.
We found three interesting things, as you can see in the video below:
1) The strobes recycle and fire at the same rate.
2) The YS-D2 circuitry is much smoother and nicer than that of the YS-D1. The LED light promptly turns on and off to indicate power while the light on the YS-D1 was slightly delayed.
3) You can hear the YS-D2's new Audible Confirmation beep when the strobe is ready to fire again, and see the glowing back panel, which stays lit even while the strobe is recycling.
Why does recycle time matter? See the photos and caption below.
In this sequence, you can see that I was surprised by the sea lion's approach, firing too early and missing the shot as my YS-D1s recycled.
Modeling Light Features
One of the big upgrades between the YS-D1 and YS-D2 is the addition of two power levels for the modeling light. The button has been moved from the mode dial to the center of the back panel. One push turns on the modeling light at full intensity. Another push reduces the intensity. A third push turns the modeling light back off.
The YS-D2 ships with a red plastic insert to cover the modeling light, allowing you to use it as a red focus light if you so choose. Unfortunately, the piece is small and easy to lose if you try popping it in and out underwater, so decide whether you will use the modeling light as white or red before your dive.
The diffusers packaged with the YS-D2 (left) differ in that they have a red filter you can pop into place as a red focus light.
YS-D2 vs YS-D1 Strobe Control Panels
The biggest difference between the YS-D1 and YS-D2 is the control panel on back of the strobe. The mode knob on the YS-D1 has a reputation for being bumped out of position when moving the strobe head (adjusting strobe positioning), especially when using thick gloves.
The YS-D2 addresses this with a new mode knob. The shape and increased resistance make it highly unlikely to be moved accidentally. The labeling is also much, much better for firing with pre-flash, without pre-flash, DS-TTL and Slave-TTL. Each of these modes has a unique color for visual confirmation at a glance (both the ready light and glowing control panel), while clicks will help you confirm modes by feel.
The power level adjustment knob (flash exposure comp for TTL) is labeled in a way that is easy to use and understand, using the same shape as the mode knob.
The YS-D2 modeling light has been moved to its own position in the center of the control panel.
New control knobs for the YS-D2 (left) won't be bumped out of position.
YS-D2 modes left to right: with Pre-Flash, without Pre-Flash, DS-TTL, Slave-TTL or TTL
Battery Compartment Upgrades
The battery compartment of the YS-D2 features a convenient plastic divider to hold batteries in place, making it easier to load the batteries into the strobe. You'll soon know that "positives up" are left and right compartments, while "negatives up" are the top and bottom compartments (instead of reading the label every time on the YS-D1s).
The divider will make it a bit more difficult to clean the contacts of flooded strobes, but the convenience is well worth it.
A plastic divider keeps your batteries in place in the new YS-D2 strobe (left).
Strobe Weight and Size Comparison
The YS-D2 is the same size as the YS-D1 even though the black moulding is different (presumably to accommodate the new control knobs and modeling light placement). The YS-D2 also has little hooks for holding the fiber optic cable against the strobe, which the YS-D1 does not have.
Weight of the Sea & Sea YS-D2 is 22 ounces (623g) without batteries or fixing bolt, while the weight of the YS-D1 is 20.1 ounces (570g). YS mount was attached to each strobe.
The YS-D2 (left) uses a different mould than the YS-D1 but keeps the same size.
Weighing both strobes without batteries or fixing bolts.
SEA&SEA YS-D2 Strobe Review Video
by Bluewater Photo
Diving with the YS-D2 in the Sea of Cortez
From the Field, with Kelli Dickinson
At first glance not much has changed from the YS-D1 to the new YS-D2 strobe, so for those of us that already own YS-D1's is there any reason to think about upgrading? For most folks, probably not, but for those of us who like the ease of use of S&S strobes, but keep running into small pitfalls with the D1, then the D2 is a great alternative. I recently had the chance to use the YS-D2 on my trip to the Sea of Cortez and thoroughly enjoyed the new strobe.
The key differences for me that make the YS-D2 really nice are twofold. First, they have redesigned the knobs. I have found that with my YS-D1 at least once per dive I take a photo and one strobe does not fire. Puzzled at first I would glance at my strobes and notice that the mode knob on the non-firing on had been slightly knocked out of place. This happened extremely easily, and after owning the strobes for a few months, I no longer hesitated to check that when a strobe stopped firing. With the new YS-D2 this never happened. The new knobs don't have the lever for turning them and while this makes it a little tougher to turn at first, it also means there is nothing to catch or get bumped out of place. Secondly, the new illuminated back panel. It changes color based on your mode, so it was perfect for me to easily check my strobe, see it glowing green and know i was in the right manual mode. In addition, at nighttime having that panel illuminated made it easy to check my power level settings and not having to guess based on feel if I was set where I wanted.
Other new features are nice, including the small beep when the strobe is ready to fire. At first I worried it would be annoying, but I rarely even noticed it. When shooting at a higher strobe power it was useful to listen for it and know I was good to go. The redesigned power settings and TTL Compensation layout is nice too, simply look at the upper or lower portion of the circle to set you power and ignore the other. No longer is it a confusion combination of settings. I used the modeling light on my night dives as my primary dive light after I discovered that my Sola's wide beam attracted way too many krill that were present around the dive site. These lights were bright enough to see by, and when need, the new red filters you can attach to the YS-D2's diffusers work great to allow for red focus lighting which does not startle marine life as much as a white light does.
Overall I really enjoyed the new YS-D2 and think that the new features are a nice addition and step forward from an already fabulous underwater strobe. If you don't own a D1 yet, I would strongly recommend the YS-D2. If you already own the YS-D1, but think any of these new features will really make your diving and photography more enjoyable then definitely upgrade to the new version - you will not regret it.
Young sea lion below the surface. Olmpus OM-D E-M5 Mark II with Olympus 8mm fisheye lens and dual YS-D2 strobes. Photo: Kelli Dickinson
Brown Cheek Blenny. Olmpus OM-D E-M5 Mark II with Olympus 60mm macro lens and dual YS-D2 strobes. Photo: Kelli Dickinson
Orange Throat Pikeblenny. Olmpus OM-D E-M5 Mark II with Olympus 60mm macro lens and dual YS-D2 strobes. Photo: Kelli Dickinson
Close focus wide-angle. Olmpus OM-D E-M5 Mark II with Olympus 8mm fisheye lens and dual YS-D2 strobes. Photo: Kelli Dickinson
Looking out. Olmpus OM-D E-M5 Mark II with Olympus 7-14mm lens and dual YS-D2 strobes. Photo: Kelli Dickinson
Brent Durand is a weekend wanderer, story teller and image-maker from California. Brent is editor of UWPG. Follow UWPG on Facebook for daily photos, tips & everything underwater photography. View more of Brent's work or follow his imagery through www.BrentDimagery.com.
Kelli Dickinson is an avid diver, manager of Bluewater Photo Store and an industry expert on mirrorless cameras and housing options. You can reach her by email at email@example.com.
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Sea & Sea has a new Optical YS Converter available for their latest housings, including the MDX-70D and MDX-D7100. It’s a great option that many divers will want to add on to their system, but what is it? What is TTL and what does this new converter do?
There are two ways to shoot with strobes: manual power adjustments or TTL (auto) power. Some photographers shoot manual all the time, some shoot TTL all the time and some shoot TTL in some situations and manual in others. Below we discuss the benefits of Sea & Sea’s Optical YS Converter and what they mean.
Optical – No Need for Sync Cords
Sea & Sea’s Optical YS Converter converts the electronic TTL signal into a light signal. This is good for two reasons. First, photographers can use fiber optic cables instead of sync cords. These are smaller, more reliable, cheaper, easier to maintain and will not flood (sync cords can flood at strobe or housing bulkhead end and require daily o-ring maintenance).
The second benefit is that photographers can use fiber optic cables (light signal) without using the camera’s internal flash, since the Optical YS Converter converts the electronic signal into a light signal. Rapid firing of strobes with fiber optic cables was previously limited to the recycle time of the camera’s built-in flash, but this is no longer an issue. It was one of the key benefits to using sync cords over fiber optic cables, so I predict sync cords to disappear once all housing manufacturers start using optical converters. Divers also save camera battery life by not using the camera’s built-in flash.
Left: 2x Sea & Sea Fiber Optic Cable II. Right: Dual sync cord (Nikonos to Sea & Sea)
Change from TTL to Manual During the Dive
Another major feature of Sea & Sea’s Optical YS Converter is the ability to switch between TTL and Manual power with the press of a button. Divers must no longer commit to TTL or manual before the dive, instead choosing their strobe power mode depending on the current situation.
Switching from manual to TTL is easy mid-dive.
Blue LED means TTL is active.
Green LED means TTL is not active.
No more bulky TTL converter dangling outside the housing. The Optical YS Converter is built into the housing, eliminating a strobe bulkhead and chances of it flooding.
Simply plug the fiber optic II cables into the ports - nothing is outside the housing!
Other Key Features
Fine-tune strobe power via EV controller on back of YS-D1, YS-01 or YS-110a strobe
Battery level indicator
Blue LED light indicates TTL mode is active. Green LED light indicates manual strobe power
Auto power off and easy re-activation to save battery life
The Sea & Sea Optical YS Converter is an optional (although highly recommended) accessory. If purchasing with a new housing, the team at Bluewater Photo can easily install it. For those adding it to their housing, installation is user-friendly, with two screws to attach the converter to the inside top of the housing.
So do you need the Optical YS Converter? Different divers will have differing opinions, but with the accuracy of the converter and Sea & Sea’s new Fiber Optic Cable II, you’ll be kicking yourself for missing a shot you could have saved with TTL.
A great example is a light-colored school of fish that swam quickly by much closer than expected, blown out by your default “swim-around” strobe power settings. An optical TTL converter is certainly on my list to start saving for!
Brent Durand is an avid California beach diver, photographer and writer dedicated to capturing unique underwater, ocean lifestyle and adventure images. Brent is editor-in-chief of the Underwater Photography Guide. Make sure to follow UWPG on Facebook for updates on everything underwater-photography.
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To be honest, I've never really given my strobe arms and clamps that much thought. Most of the designs out there look similar and I assumed they all performed about the same as well. My only real complaint is that most of them will not hold my heavy strobes in place when I hand my rig up to the boat. I am currently using Ikelite 160 strobes and before that, Ikelite 200 strobes, neither of which you could classify as "small." No matter how hard I would clamp down on the arms, they still had a tendency to flop around whenever I handled my camera out of the water. I was telling my sad story to the guys at Beneath the Surface and they suggested I give their arms and clamps a try on my most recent trip to Palau.
The first thing I noticed when the package arrived was the anodized blue handles on the clamps. They just looked cool! The second thing was the build quality. These clamps are manufactured extremely well. All Beneath the Surface products are backed by a limited lifetime warrantee and made in the USA. When I put the whole system together they did indeed have clamping power. Even on the hike to Jellyfish Lake I didn't need to clip my strobe arms together to keep them from flopping around. Underwater, the clamps performed equally well. With only a slight amount of pressure, they had enough holding power to keep my strobes in place but were loose enough that I could easily reposition my strobes without adjusting the tension on the clamps. The clamps also feature a beveled edge to allow more sideways movement.
Today many manufacturers are building increasingly bigger buoyancy arms, but Beneath the Surface has gone in the complete opposite direction. What they lack in floatation, they make up for in a small, sleek design. The arms are made from 304 stainless steel tubing and the balls are machined from 6061 aluminum. They are then hard anodized and topped with an EPDM o-ring. The minimalist approach is also a blessing when it comes to packing your rig, taking up almost no room in your camera case. I hadn’t been using much floatation on my system so I hardly noticed the difference with other arms. I also like the small size and the option to fold up the arms as close as possible. For those that must use floatation, Beneath the Surface is currently designing a buoyancy float for their arms that should be available in the very near future.
After 10 days of constant use and some intentional abuse just to see if I could make them fail, the arms and clamps look as good as new. Even with the extreme over-tightening that I put them through, I only see some light wear to the finish.
Beneath the Surface produces a number of other products including flex arms, pivot trays and bridge bars. To see more of their innovative products, check out their website at www.beneaththesurface1.com.
About the Author
Todd Winner is a professional underwater photographer and cinematographer, PADI scuba instructor and owner of Winner Productions, a boutique post production facility catering to Hollywood's most elite cinematographers. Since taking up underwater photography in 1990, Todd Winner has won over 60 international underwater photo competitions. His images have been published in numerous magazines and online publications. His work has been featured in commercial advertising, museums and private galleries. To see more of Todd's work or join him on an underwater workshop, please visit www.toddwinner.com.
Please support the Underwater Photography Guide by purchasing your underwater photography gear through our sister site, Bluewater Photo & Video. Click, or call them at (310) 633-5052 for expert advice!
The Sea & Sea YS-D1 strobe, which became available April 2012, is Sea & Sea's first new strobe since the YS-01 was announced in December 2009. It replaces the YS-110a, which made its debut in 2008.
Special sale, $70 off the YS-D1, 1 week only starting Nov 22nd 2014, full details here.
I was able to take the strobe to Catalina Island in Southern California this past weekend on a Bluewater Photo charter, and I tested it out with various setups including a Nikon D7000, Canon compacts, the Olympus XZ-1 and others. We also had some other strobes with us including the YS-110a and the Inon Z240. Let's see how it performed!
The YS-110a, YS-D1, and Inon Z240
YS-D1 strobe back. The right dial controls strobe power in manual mode, and exposure compensation in optical TTL mode.
YS-D1 strobe key features
More power than the YS-110a or Inon Z240
It was important for me to compare apples-to-apples, so I did my comparison tests with the 100 degree diffuser on the YS-D1 strobe, the 0.5 stop diffuser on the Z240, and the standard diffuser on the YS-110. I think this is how most people will use these strobes, and it is probably the fairest comparison.
If a strobe is a "stop" stronger than another strobe, it means it puts out twice as much light. So if you can shoot a subject at F11 with one strobe, you can shoot the subject at F16 with a strobe that is 1 stop stronger.
Tests showed the YS-D1 about +2/3 to +1 stop stronger than the Inon Z240, and +1 1/3 to +1 2/3 stops stronger than the YS-110a.
During my macro test shots the YS-D1 proved to be an additional +1/3 stop over my tested wide-angle shots. This gives the macro user the added benefit of "powering the strobe down" even further, offering softer light, for those f22 macro situations.
This is a nice boost of power, and it will really help when shooting into the sun, and with wide-angle shots where you can't get as close as you want, or really need to shoot at a small aperture. For even more power, you can remove the 100 degree diffuser from the YS-D1 and get another +2/3 of a stop of power. Read more about strobes and diffusers.
Taken at F16, ISO 100. I could easily shoot at F16 without getting too close to the subject, which was really nice. I'm sure that F22 would have been no problem, which will make shooting bright backgrounds, especially sunballs, easier to control. I hope the viz is better next time so I can try some sunball shots.
Bristle worm in Anilao, taken with the YS-D1 strobe with a Nikon D7000, TTL mode.
Sea & Sea YS-D1 strobe in use in Anilao. F22, 1/250th, ISO 100.
Trumpetfish from the UWPG Anilao 2012 workshop.
Taken with dual YS-D1 strobes.
YS-D1 strobe, taken at F22
YS-110a strobe, taken a.t F13, same distance as above photo. -1 2/3rds stop difference
YS-D1 strobe, taken at F22
Inon Z240 strobe, taken at F16 at the same distance as the above photo, showing a -1 stop difference
YS-D1 strobe, taken at F18
Inon Z240, taken at F14, same distance as the above photo, showing a -2/3rds stop difference
YS-D1 strobe, Tokina 10-17mm lens at 12mm, F22
Inon Z240 strobe, Tokina 10-17mm lens at 12mm, F18. The YS-D1 was +2/3 of a stop stronger overall.
YS-110a strobe, Tokina 10-17mm lens at 12mm, F14. The YS-D1 was +1 1/3 stop stronger overall.
TTL Exposure compensation
The strobe allows you adjust exposure when shooting in optical TTL mode. You can increase exposure by +1.5 stops, or decrease it by -1.5 stops. This is a really nice feature, and in my tests with a Nikon D7000, it worked very well. Note that results may vary slightly depending on the subject, the metering mode your camera is in, and the camera used. Read more about optical TTL.
Recycle rate - fairly quick
On full power, the strobe recycles in 1.9 seconds, just about the same as the YS-110a or Inon Z240 on full power. However, when the strobe is turned down half a stop, it recycles in about a second, and when turned down 1 stop, it is less than a second. This means, when shooting at the same power that your old strobe did on full power, you'll notice a much quicker recycle time.
Note that when using optical TTL, you may be limited by the flash recycle time on your camera, or by a limitation on the number of sequential flashes your camera can make. Of course the best way to really utilize the fast recycle time of this strobe is to use an electronic sync cord.
Reduced size & weight
The YS-D1 is slightly smaller and weighs slightly less than the Ys-110a, and it is slightly shorter than the YS-110a. It weighed about the same as my Inon Z240, and is about the same size, although the dimensions of the YS-D1 and Z240 are quite different, the Z240 is more fat and stubby.
TTL works with the Nikon D7000, other compacts
The optical TTL functionality worked well with my Nikon D7000. Exposures were spot on.
I also tested the optical TTL with other compacts, it seemed to work well although results were spotty with the Olympus XZ-1, it worked well on land but underwater it has some issues - I think the variable pre-flashes of the XZ-1 may occasionally confuse the YS-D1 - further testing will be needed.
Possibility of three different beam angles
The Sea & Sea YS-D1 comes with 2 different diffusers. I recommend people use the 100 degree diffuser for most of their shots. It will be wide enough for most wide-angle shots including shots with a fisheye lens, and it only reduces the power by -2/3rds of a stop. The stronger diffuser is a 120 degree angle diffuser.
Better controls, ergonomics and little extras
The dials are very nicely implemented - definitely the easiest dials to use out of any of the 3 strobes. Sea & Sea made a nice little "hatch" that opens up to expose the fiber optic connection point, a nice touch. I like how quickly I can open the battery compartment, just like with all the Sea & Sea strobes. Note - the YS-D1 takes 4 AA batteries, and uses the same o-ring as the YS-110a and YS-01 strobes.
Last, but not least, a ball adapter is included with the strobe, which can replace the YS mount and reduce the form factor of the strobe even further.
LED Target light
The built-in LED target light not that strong. It is certainly not even close to being a focus or video light. But it is nice to have as a back-up light.
Sea & Sea YS-D1 Review - conclusions
Overall - I give the strobe a big thumbs up. It was difficult to find anything about it that I didn't like. It is strong, small, easy to use with gloves, and has a great exposure compensation switch. I used the strobe in Anilao, Philippines for two weeks so look forward to some more photos and feedback. I lalso used the strobes for 10 days in Raja Ampat, here are my Raja Ampat photos with the strobe.
And at $699 retail in the USA, the price is great!
Sea & Sea YS-D1 - where to buy
Please support the Underwater Photography Guide by supporting our sister site, Bluewater Photo, who is usually well stocked up on the YS-D1 strobe.
Sea & Sea YS-D1 - official specs
[Guide Number (ISO 100/m) (land)] : 32, 24 (with Diffuser 100 attached), 20 (with Diffuser 120 attached)
[Beam Angle] : 80°x80° (without diffuser), 100°x100°(diffuser 100), 120° x 120° (diffuser 120)
[Batteries] : 4xAA A: 6V Ni-MH: 4.8V
[Number of Flashes*1] : A: 150 Ni-MH: 250
[Recycle time (full)*2] : A: 2.8 sec. Ni-MH: 1.9 sec.
[Color temperature] : 5600K
[Color temperature w/diffuser] : 5250K
[Depth rating] : 100m / 330ft
[Dimensions (WxHxD)] （Excluding protruding part(s) and the arm holder.）: 87x135x111mm / 3.5 x 5.4 x 4.4 inches
[Weight] : 650g / 22.9oz (w/o batteries) * Attached a YS Mount
Strobe Adaptor and a fixing bolt to the Strobe.
[Underwater weight] : 0.5g / 0.02oz(w/ batteries)
Exposure control: DS-TTL II, Slave TTL, Light level control dial (GN): 1 / 1.4 / 2 / 2.8 /4 / 5.6 /8 / 11 / 16 / 22 / 32 (11 steps)
Pre-flash control: Equipped with pre-flash cancel mode
DS-TTL II function
Auto power OFF function
Sync cord: 5-pin Sync cord/N, Fiber-Optic Cable (L-type)
Over-pressure relief valve
LED target light
What to do if you flood your strobe - find out in this vide
Please support the Underwater Photography Guide by purchasing your underwater photography gear through our sister site, Bluewater Photo and Video. Click, or call them at (310) 633-5052 for expert advice!
The Inon S2000 is small, tiny. That was my first impression. I'm used to my large, well built Z240's, and the S2000 also had a cheaper feel. That is to be expected, as it is a less expensive strobe. This is a great strobe for underwater photography and comes highly recommended.
Optically fired, does not support firing by sync cable
Manual and S-TTL modes
No aiming/modeling light
Ability to fire without a fiber optic cable. This is a great feature. Underwater, the strobes can be placed away from the camera rig, allowing for creative side lighting and backlighting of subjects. The strobe will simply slave off another strobe or flash, as long as the receiver can "see" the flash.
Takes 4 AA batteries
Recycle time: I measured it at 2 seconds.
The strobe is much smaller than my Z240.
Inon S2000 Strobe Power
For macro, this strobe was surprisingly strong, only 1/2 stop weaker than my Inon Z240 when it did not have a diffuser on. With the diffuser on, the S2000 strength was 1 1/2 stops below. The Inon diffuser says that it's only a 1/2 stop diffuser, so I am going to redo these tests again soon, along with testing wide-angle power and coverage.
Using the strobe in Manual Mode
When the Inon S2000 is used in manual mode (turn the left switch to "M"), the magnet switch is used to tell the strobe whether to ignore pre-flashes or not. Normally the magnet is not inserted into the hole, but when using Canon point and shoot cameras like the Canon S90, G10, or G11 on manual mode, you want to insert the magnet, and set the Canon flash power to it's lowest setting. This is because Canon compact cameras do not preflash or support TTL when in manual mode.
I did several test shots with the S-TTL feature, and exposure seemed to be good. Fine adjustments to the S-TTL exposure can be made by turning the main dial to the left ("A") or right ("B") one click. The amazing thing about this strobe is that it doesn't need a fiber optic cable. As long as the little mirror-resembling receiver can "see" the flash from your internal flash or another strobe, it will fire.
The magnet switch is not used when using the strobe in S-TTL mode.
The YS-110 is a solid, popular mid-range strobe used by high-end compact camera underwater photographers, and dSLR underwater photographers. I've used it extensively for macro and wide-angle and it works well and is reliable. It's fairly small, light, and slightly negative underwater which is very nice.
I own 2 Inon Z240's, and I love them. Here's some initial impressions:
Inon Z240 Pro's
Excellent build quality. perfect o-ring, nice yellow color so you can see dirt. Excellent battery compartment, this would be very difficult to flood. You can see the oring at all times (clear compartment).
Stronger than YS-90,Ys-110,Inon Z220. Some people say they are stronger than Ike-125s. Fast recycle time. I measured the Inon Z240 as 1 stop faster than a Ys-110 or a Ys-110s, and 1 1/2 stops stronger if both had diffusers on
Very small, very lightweight.
Great angle of coverage.
Uses 4 AA batteries. Batteries usually will last for 3 dives of heavy shooting.
Type 3 strobe comes with a high-intensity focus/aiming light
Works great with my Sea & Sea TTL-converter III for nikon, for macro & close focus wide angle.
Has the famous "S-TTL" feature that implements TTL via a fiber optic connection, mimicing the camera's pre-flash. (Not applicable when using sync cords).
Has "pre-flash cancel" circuitry that helps reduce the strength of a camera's preflash, resulting in longer battery life for the camera, and shorter internal-flash recycle times. (Not applicable when using sync cords).
Diffusers screw in, making it very hard to lose them. I've lost a couple diffusers already from my Sea & Sea strobes. It also makes it easy to place colored gel filters behind the strobes.
Inon Z240 con's
Color temp of 5500K is good enough for wide-angle, but not ideal, some professionals prefer warmer strobes for wide-angle
More expensive strobes have more even coverage, even with a diffuser coverage is not perfectly even when shooting very wide-angle (e.g. - with a 10mm fisheye lens), there is light falloff at the edges of coverage.
Inon Z240 type 3 strobes recommend using low-discharge rechargables such as Sayno Eneloops. This really isn't a big deal, Eneloops are great batteries, inexpensive, can be recharged in any regular charger, and don't lose their charge over time.
For a point and shoot camera, an Inon D2000 or S2000 will also work fine.
There's some example photos from the Phillipines taken with these strobes here.
Here's a recent cuttlefish photo taken with these strobes:
cuttlefish, bali with inon z240 strobes
Inon Z240 Settings & configuration
The Inon Z240 manual is famous for being hard to understand. Here's the Inon Z240 configuration & settings I use with my Sea & Sea D300 housing and Sea & Sea TTL converter. Note - when used with a TTL converter, the lower right button must be down, not up.
For normal TTL - put the left dial = S-TTL , right dial = (doesn't matter)
For FullPower - Simply turn your S&S TTL converter dial all the way to the left for manual, and just leave the left dial on S-TTL (nice feature), or you turn the left dial to FULL
Manual Power - Set TTL converter dial to manual, turn left dial to M, adjust right dial as needed. Also use the manual power setting for a direct sync cable connection to a dSLR. Note - the "full" setting is 1/2 stop stronger than the strongest manual setting of 11.
Inon Z240 Dial Settings with a fiber optic cable
The Inon Z240 strobe can be triggered by a camera's internal flash.
S-TTL - use this setting for TTL with your Inon strobe. The strobe will mimic the pre-flash. The right dial should be at the 12'oclock position. Turn the right dial to the left or right one click for some amount of exposure compensation.
Low - The same as S-TTL, but with less of a chance of over exposing the subject.
Manual - for manual power settings (but will not do a full dump)
Full - for a full dump (maximum power) of the strobe
Inon Z240 Type 1,2,3,4 differences
Inon Z220 - Z240 predecessor - great strobe, but not as strong as the Z240
Inon Z240 Type 1 - Original Z240 strobe
Inon Z240 Type 2 - Added compatibility with Nikon D80/D200 (and future models) when used with fiber optics, because of the increased number of pre-flashes with these cameras.
Inon Z240 Type 3 - Has a stronger modeling/spotting / aiming light, the bulb changed to an LED. Recommends low-discharge batteries such as the Sanyo Eneloop or Powerbase instant, to prevent overheating, especially when the modeling light is on.
Inon Z240 Type 4 - Can be fired optically without a fiber optic cable. The TTL flash sensor is many times more sensitive than the previous types. Also, it is safer to use regular AA rechargables.
These differences are the same for the Inon D2000 strobe.
Inon Z240 Issues to be aware of
Manual mode will not fill on full power, it's a half-stop below full power. Only the "full" setting will do a full dump.
Don't make the mistake of ordering the strobes witout h the proper adapter (e.g. - Ultralight AD-IN) to connect to your arm/clamps, they are around $27 each.
Be very careful not to loose the metal screw that closes the battery compartment, it's easy to drop.
Sync Cable for the Z240
The Inon strobes take a nikonos 5-pin cable, just like Sea & Sea strobes, but different than Ikelite strobes.
Official Inon Z240 Specs
5500K color temp. My macro shots with the 0.5 diffuser are usually properly white balanced at 5100-5200K in the adobe raw editor.
Guide number of 24 on land
Angle of coverage 100 degrees, 110 with diffuser
Recycle time 1.6 seconds on a full dump, much faster otherwise
Flashes per charge - 240
Size - 4.8 x 3.94 x 3.9 in (122 x 100 x 99 mm)
Weight - 20.5 ounces (580g) on land, almost neutral underwater
Able to be fired with sync cords or fiber optic cable.
Ikelite DS-160 substrobes are about the same strength, are larger and heavier but have a cooler temperature which can be more desired for people shooting wide-angle underwater photography.
Recommendation and Price
Highly recommended, great choice for a strobe that can be used for macro and wide angle, for compacts and dSLR users. If you are compact user just doing macro/fish photos, you may not need this expensive of a strobe.
The price can vary depending on country, $750 in the USA as of April 2009.