Nikonos Speedlight


Text and Photos by Bob Warkentin

Strobe Construction: The Battery Compartment
The SB103 Battery Chamber: The Battery Cap | Opening the Battery Compartment | Closing the Battery Compartment
The SB102 Battery Compartment: Opening the Battery Compartment | Replacing the Battery Cap
Big Strobes Stored in Small Cases

The Flash Cable
The Two Plastic Dust Covers
Frozen Flash-Cable Connectors
Removing the Flash Cable From a Nikonos V

Installing a Greased O-ring on a Flash Cable
Checking the Strobe/Cable/Camera Communication
Double Strobe Cable

Ah, the electronic age with its portable gadgets that are built by humans for humans that are supposed to turn the otherwise drab blue-gray world beneath the oceans into a beautiful panorama of wonderful colors. When it works well, everyone has got a name for this invention: my equipment and I know how to use it; the best anyone ever built; even Nikon has a real name for it, the "Speedlight". We have names for it as well when nothing goes right, and of course all agree that Nikon didn't build it correctly (or should at least have made salt water dry).

What human would want to remember that in order for just the flash to flash when the camera button is pushed, the strobe must be on, the strobe batteries must be fresh and the right kind, the flash must be water tight with good O-ring seals, the flash cable and each connector must be in good condition and no excess grease on the contact points, the camera must be in good working condition as well as its batteries (if any). Even if all of these things are remembered and checked by you before diving, who cares. It is still the manufacturer's fault about something because you can't get 36 out of 36 pictures to come out like the ones in Ocean Realm magazine.

Well, in reality pros use their equipment far more than the average sport diver. Remember, their Nikonos strobe is identical to yours, and it must function exactly the same way yours does, dive after dive after dive! As such, they have learned that safety practices with their equipment (with which they make a living) is essential in order to complete the job for which they were hired.

So, if you are the typical human who only wants to learn how to get proper strobe-fill in your picture, this article ain't for you. If you want to learn about the strobe and how not to destroy it, then let's look at what all goes in to making your flash flash, and the typical human "destruction" mistakes.

Strobe Construction
The Battery Compartment

Batteries! Electronics don't work without electrical power of some kind. If it is a self-contained portable electronic device, then it must have a self-contained portable power source. This means batteries, and a safe, water tight place to put them. But if the human has to put in batteries, it's a sure bet this human can also leak in water through the same area.

Battery compartment
Photo 1

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The SB103 Battery Chamber

First of all, although compact and appearing to be a sealed chamber, the battery chamber is not water tight in and of itself. So yes, human, you are still responsible for seeing to it that the O-ring on the battery chamber cap is in good condition and properly lubricated.

"Just a little water in there?" you say. "Not enough to hurt anything!" And besides you got it out by blowing it dry so it couldn't have fallen into the main (expensive) electronics chamber.

Batteryv chamber
Photo 2

Well, from photo 2 you can see that from the very beginning of the battery chamber all the way to its back (the spring contacts), there are three areas where water can leak out of the battery chamber and directly onto the electronics. In the order of most common human "wet mistakes", they are #1: Whoops, just a few drops fell in when I was removing the battery cap to change batteries; #2: Whoops, the cap was off and the strobe sitting face down when a wave came into the boat; #3: I heard something once that you need to do something about an O-ring on the battery cap before diving, but where's that O-ring located anyway?

The Battery Cap

The relatively large battery cap of the SB103 consists of 2 pieces (3 if you count the O-ring). The 4 holes on the outer edge of the cap is to allow for SOME drainage of the large amount of water that collects around the screw threads, the O-ring seat area and up under the cap during diving.

Battery Cap
Photo 3

Since the O-ring on the cap seals INSIDE the mouth of the battery compartment, and not all of the water drains away from the area under this large cap, those of you who unscrew and remove the battery cap (after diving or within 7 to 10 days after last diving) while the strobe is sitting face down on a table are just plain asking for trouble. As the O-ring seal is opened, the water still trapped around the cap has a direct path to the inside of the strobe, thanks to gravity.

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Opening the Battery Compartment

I know, it looks silly holding the strobe face up, unscrewing the battery cap up-side-down and pulling downwards. It's simply awful that not only does the battery tray fall out into your lap or onto the table, but so does all that messy water that you will have to wipe off of your legs or the table. After all, if you had let those drops of water fall into the strobe, it shouldn't cost more than a couple of hundred of dollars to repair the damaged electronics when you got back home and besides you could have borrowed someone else's strobe to destroy likewise the next day, right?

Let gravity work for you, always! And after opening the compartment, don't forget to towel dry the inside of the orange plastic mouth of the battery compartment before you place the strobe face down to change batteries and re-cap the chamber for the next dive.

Inconvenient technique? Now that you know that there is a 1/4 inch wide opening at the bottom of the battery compartment just on top of the main power board just waiting for a drop or two of water to fall into and onto, you decide.

Closing the Battery Compartment

Yes, even here there is a technique to be followed. It should save you from either splitting the mouth of the battery compartment (fully flooding the strobe) or striping the screw threads on either the cap or the mouth of the strobe, or seating the O-ring lopsided (flooding).

Battery compartment
Photo 4

Place the cap over the center of the mouth of the battery compartment. Then push down on the center portion of the cap (the part with the O-ring) with one finger. Continue putting downward pressure on it with your finger while you use the other hand to screw down the outer portion of the cap. It works first time, every time!

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The SB102 Battery Compartment

SB102 battery compartment
Photo 5

From the SB103 battery compartment whose opening is 1 1/2 inches in diameter to the SB102 whose opening is 4 1/4 inches in diameter, when opening this wet battery compartment I always tell myself that I am opening a VERY expensive strobe which I feel I am a thousand times more likely to get water into because of its large size and weight if I open it wrong. Since the access to the battery compartment of a SB102 directly exposes other parts of the strobe to water drops stupidly falling off of a wet battery cap (or face and hands) and into the strobe---from gravity and human ignorance---it is beyond me why water droplet damage continues to happen when there is a simple way to prevent this from happening.

Photo 6

Nikon has provided a horse shoe shaped cover that covers the high voltage capacitors (photo 6) so that direct water contact is not possible during battery changes. Even so, a human can still leak water into the main electronic compartment from every point all around the O-ring seal (photo 7) as well as from the base of the spring contact plate for the battery tray (photo 8).

O-ring seal
Photo 7

The major sources of water leakage/damage to this strobe have come from #1: the improper removal of the battery cap after diving (or within 7 to 10 days after diving); #2: improper storage of a very large strobe in a small foam lined camera case; #3: improperly maintained or seated O-ring and cap.

Battery tray
Photo 8

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Opening the Battery Compartment

If you skipped this part above when I talked about the SB103 because you didn't have one, then you better go back and read it. The same concepts apply: let gravity work FOR you, not against you.

For the 102 strobe, the cap is held onto the strobe by two spring loaded clamps. As above, the O-ring seal is contained on the cap itself and seals INSIDE the mouth of the strobe (photo 7).

Not only does the O-ring channel retain water after diving, but so does the two clamps as well as under the rotating scale mounted on the back of the cap. Since the strobe is quite large, weighing 4 lb. 10 oz. with batteries, the human tendency is to place this heavy strobe face down and lift off the light weight 10 oz. cap. It's so easy. Gravity not only holds the 4 lbs. of strobe down onto the table (I haven't seen one float in the air yet) but also lets all the water collected on the cap to fall into the strobe.

"Wipe off the excess water from the cap and O-ring channel before you open it!" you say. Good idea except you forgot that you can't do that to the O-ring channel until the cap is fully opened to expose the wet O-ring. At the mouth opening, the interface between the outer case (orange plastic) where the O-ring seals and the main inner electronics (black plastic) is only 1/4 inch. So, the water drops from the wet O-ring don't have far to move (from gravity's help) to where they can get inside the electronics chamber and fry the electronics.

So, you no doubt have figured out how to open the battery cap properly after diving. That's right, upside-down and on the table. Then towel drying off the inside of the mouth of the orange case (the O-ring seat) before turning the strobe on its face.

Replacing the Battery Cap

This is a two person operation in my opinion to get the O-ring properly seated and it must be performed with the strobe face down! So be careful and watch out for falling drops of water (your face, hands, or those of your helper's!).

Align the mark on the edge of the cap to the one on the strobe case. (Since the strobe is yours, you be the one who is responsible for seating the O-ringed cap properly.) Seating the cap down with even pressure with your hand (do it as many times as necessary until you feel confident), continue pushing down on the cap while your buddy simultaneously (and at the same time) latches both latches with both hands.

Remember that the spring loaded battery tray will be fighting against you while you are reseating the battery cap. So, if you don't apply continuous even pressure in reseating the big cap, you run a very high risk of improperly compressing the O-ring. So, look at your check book before you decide to do this all by your self. It may remind you of the proper technique to use.

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Big Strobes in Small Cases

For those of you who have owned the smaller SB103 strobe, which was beautifully housed in your architecturally designed foamed camera case, and decided to "upgrade" to the larger SB102 strobe, well guess what! No matter how much foam you hollow out of your old camera case, if the overall INSIDE depth of the case wasn't at least 5 3/4 inches (5 1/4 inches for the strobe if laid with the latches diagonal and at least 1/4 inch or more each for the full compression of any foam, top and bottom-you measure your own), then this fancy foamed lined "egg carton" is going to cause your "102 egg" to become egged shaped. Where? At the mouth of the battery compartment of the main case where the O-ring is!

No, it doesn't happen immediately, but during those prolonged periods of time of safe, "protected by the camera case" storage until the next dive trip. I have seen camera cases packed in exactly the same manner as suit cases: if you can sit on it and it closes, it is properly packed. And I guarantee you that the orange case at the mouth of the battery port gets a little more than just "wrinkled" like clothing.

So, after you have measured the actual depth of your camera case, if you find out that there is just barely 5 inches left after allowing for the space needed for foam compression, I strongly suggest that you adopt the policy of using the camera case only for transportation of the strobe. Then during periods of storage, remove the strobe from the case. Or, just go buy another $125.00 camera case (easy words for me to say, right!) that is deeper internally to safely house during both transportation and storage that expensive (suggested list $1105.00, WOW!) SB102 strobe.

One final point. The O-ring sealed battery cap requires special attention to install it onto the strobe case properly as explained above. If you have had the strobe for a while and during the cap's installation, you feel like it has taken an extra measure on your part to seat the cap "properly" and therefore might have been deformed by your camera case, then please remove the "old" O-ring from the cap (which no doubt has been flattened during storage and has lost a lot of elasticity) and replace it with your new one. This way, if there has actually been only a little deformation of the case mouth, then the new O-ring should have enough uncompressed rubber to fill in areas of deformation.

"Does this mean that from now on I will have to buy new O-rings for this strobe before every dive trip?" Yes, unless you practice CPR (Compression Prevention for Rubber) as explained in the "Lens" articles or "O-ring" articles. It is too late to make any repairs to the strobe case to straighten it, but you might want to look into buying a larger camera case to prevent further deformation of the strobe. If the strobe becomes more deformed, sooner or later even the O-ring won't be able to plug up the gaps!

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The Flash Cable

Ah, the yo-yo string, the "handle" by which all "boat guides" retrieve our photographic equipment, the one item most frequently photographed underwater, the thing that always gets tangled up in your dive equipment! Regardless of what you call it or say about it, if the wires are broken or you have gotten grease onto the contacts during O-ring maintenance, it won't work, the strobe won't work, and even the camera won't work! It can even flood the camera! Now, what were you calling this delicate, most important thing a moment ago?

The Two Plastic Dust Covers

First and foremost, if you want to flood your camera and do extensive damage to the electronics, continue to use the plastic dust covers which came installed on each connector to cover the ends of your flash connectors, and never change the dust-free O-rings!

"Why? They snap on so beautifully and never fall off! My O-rings really stay clean!"

Well, if you are one of us who occasionally wears underwear, then the reason is obvious. At the end of the day, we almost have to peal the elastic out of the folds of our skin. Our skin now has been compressed to look exactly like the elastic of our underwear. Just like our skin and underwear, caps that SNAP ON and STAY ON do so only because there is an O-ring present to be compressed. After a year or so of wearing the dust cover, the O-ring has been flattened to such an extent that it won't provide a water tight seal for the flash port of the camera (or strobe). This will definitely flood the camera!

Try this simple "I didn't realize the problem" test. Pop off the cap and remove the O-ring. Replace the cap onto the connector, merely hold the connector up-side-down and watch that little cap fall right off (and hopefully into the garbage can for ever!).

"But how do I keep that dust off of the O-rings and out of the flash contacts?" you say. Ever heard of sandwich bags with zip tops? They are cheaper than a camera flood, and easier to find if you loose one than buying a replacement cap. You also might decide to change the old flattened O-rings on both ends, reckon?

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Frozen Flash-Cable Connectors

Flash cable connector
Photo 9

Would you believe that there are people who connect a flash cable to both a strobe and a camera and leave them connected all week long while diving? Of course not! Who would be so crazy to do that?

Photo 10

Believe me, there are too many people who do this. And at the end of the week, when they try to get the cable off of the strobe, the whole connector is frozen and breaks the flash cable connector right out of the strobe (and you can't just say "whoops", and stick it back in for diving). Or, unscrewing the camera side connector breaks all of the flash pins in the camera.

Photo 11

The problem here is that both connectors consist of two parts: one that contains the cable wire and connector and is designed to remain stationary, while the other which IS SUPPOSED TO rotate around this connector to screw it onto or into something holding it in place. After a week of diving, the salt residue has "welded" these two separate pieces together. So, when you unscrew one, you wind up twisting the other which was not designed to be rotated. The result is a damaged cable or strobe or camera, or all three and your pocket book!

To prevent this, disconnect the cable from both the strobe and camera each day. Also, if it is not too much trouble, would you also clean off the metal shaft around which the rotating piece rotates and just maybe put a little O-ring grease on the metal shaft where the rotating piece is located.

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Removing the Flash Cable From a Nikonos V

We have talked about this in previous chapters, but let's do it one more time.

When we install the dry flash cable connector into the camera, we hold the camera up-side-down so that we can see the white alignment dot as well as watch what we are doing. No problem so far. And when we disconnect the cable after diving we hold it up-side-down to unscrew the connector. BIG PROBLEM for Nikonos V's.

Since the threads holding the O-ring sealed connector are on the back side of the O-ring, they fill up with water during diving. So, when you unscrew the connector with the camera up-side-down, as soon as the O-ring sealed connector is started to be removed, water is starting down into and onto the flash pins of the camera.

No real problem for the three tall pins; but for the two short (TTL) pins, this is corrosively devastating. You also run the risk of having water leak into the camera. To prevent this, unscrew the connector from the bottom of the camera with the camera right-side-up. Then dry to open flash port with a tip of a towel and now you can turn the camera up-side-down for what ever reason you want. Where did the water drops go? Down to your lap (with gravity), not down inside your camera (with gravity)!

Installing a Greased O-ring on a Flash Cable

If you want to prevent any electrical contact between strobe and camera, grease up the connector contacts while cleaning and replacing the O-ring. No one will notice your dumb mistake and you can blame it on your spouse or Nikon for the strobe not working properly.

Remove the O-ring by sliding it with your fingers only to one side of the connector. Grab the excess and lift it off. After cleaning both the O-ring and the O-ring grove, re-grease the O-ring. Remember, if you now wash your hands to remove the grease and then touch a greasy O-ring, your fingers become greasy again. Don't fool yourself!

With your greasy fingers touching a greasy O-ring, RING the neck of the connector with the O-ring. Now, bring your thumbs (both of them) and the O-ring down the side to the O-ring channel. Once there, simply advance both thumbs around the channel and, presto: the O-ring is seated and there is no grease in the connector contacts!

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Checking the Strobe/Cable/Camera Communication

There is so much communication going on (through) that flash cable you wouldn't believe just how much! The strobe is actually controlling part of the camera operations, and the camera is controlling part of the strobe operations. Greasy or corroded contacts, broken wires, dead batteries all add up to wasted expensive film and a lousy dive trip.

Test #1. Hello, Hello! Strobe controlling camera!

With good batteries (silver oxide only, not lithium) installed in the camera, camera set to "A" shutter speed and the counter advanced to frame #1 or higher, ASA 100 setting, cock the camera, place your hand over the lens port to block all light and push the trigger. This should cause the shutter to jam open and you can't advance the lever and pushing the trigger again doesn't do anything for you. Now, turn on the strobe (batteries installed, of course) to any setting and you will hear the shutter go "click" (close). The strobe won't fire, though.

What has happened is this. The first curtain of the shutter in "A" (auto) will open mechanically when you push the trigger button, but the second curtain will only close if it has either seen enough light before triggering and computed when to close (you had your hand over the light sensor so it would not see any light to compute), or if the flash cable is good, will close when the strobe is turned on (remember, strobe "on" over rides automatic selection of shutter speed "A", and sets it to electronically controlled 1/90 second). If it doesn't close the shutter, either there is grease on the cable contacts (strobe side, camera side, or in the flash port of the camera in the pins) or, of course, you forgot to put batteries into the strobe, dummy! Or, yes, the cable is no good and you better buy another before the trip.

Test #2. TTL thinks for me.

The wonderful world of laid-back automatic shooting. Providing it is working! To test the TTL aspects of the cable, set the camera shutter speed "A", counter on frame #1 or higher, good batteries, and turn the strobe to TTL setting. Depressing the trigger button, you should see the lightening bolt (not the arrow head) at the far right of the LED's. Now, with the ASA set anywhere below 400, the lightening bolt should be on continuously; above 400 it should blink.

But, if the light remains solid (or blinks) at every setting no matter what, then you've got problems and no TTL operations! Check for greasy contacts first on the camera's contact pins (the two short ones: these are the TTL contacts, not the three tall ones) and on the camera side cable connector. If greasy, clean with a lot of cotton swabs and a little bit of alcohol.

Next, check for corrosion on these pins (using your 35mm lens magnifier, remember!). If present, you may not be able to clean and restore its operations. If you are smooth out of luck as far as TTL is concerned, you may have to use the strobe on the other three manual settings. (Note: If you continue to use the TTL setting on the strobe with a faulty cable or bad camera contacts, the actual flash output will be either full power or something less than the 1/16 power, but who knows! You better be the one who knows, right?)

Test #3. The Camera Controlling The Strobe

Set the camera to "A", ASA 100, counter #1 or higher, batteries in, and the lens off. With the strobe connected to the camera and turned on TTL, point the strobe to the front of the camera (about 6 inches away). Triggering the camera, the flash should fire. The ready light should go out and come on again in less than one second (if the strobe batteries are fresh!). Now, place the strobe face down, and block the front of the camera from light entering by placing your hand over the lens mount area. Now fire the strobe and you will have a full power flash output. This will be indicated by the ready light which will blink 11 times, go out and come back on in 6-9 seconds. (Note: For a "FULL" setting full power firing, the ready light will just go out and come back on in 6-9 seconds. It will not blink in between).

This test will show that the sensor located in the bottom of the lens mount area is working. It shuts of the strobe light at some predetermined level, or gives a full TTL indicated output if it didn't see what was sufficient light reflected back into the camera.

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Double Strobe Cable

The expensive cable no one seems to understand or can use. So, here is how it actually works, cable by cable.

The Black Cable:
The black cable is the primary cable! It works just like a single cable in terms of what it controls and how it controls it. The tests above can be used directly with this cable regardless if a second strobe is attached. THE BLACK CABLE AND STROBE SETTINGS CONTROL WHAT THE GRAY SIDE CAN DO!

The Gray Cable:
The side no one seems to understand. First, and foremost, if you want the gray side strobe to function on TTL, THE BLACK SIDE MUST ALSO BE ON TTL. It will not work independent of what ever the black side is set on. Therefore, to perform the above tests for the gray side strobe, you must have a strobe connected and turned on TTL on the black side, and block its light from reaching the camera (I put it in a box and close the lid). Now, test the gray side as above.

REMEMBER, the gray side strobe will not function as TTL on its TTL setting unless the black side is also ON and on TTL! Its other settings will function independent of the black side, power on or off, but just not the TTL.


  1. Neither the SB102 nor 103 strobes have idiot-proof water tight battery chambers. Any leakage here goes right to the electronics.
  2. Battery compartment covers can trap large amounts of water during diving. Unless you can reverse the law of gravity, open the strobes up side down.
  3. Replacing a battery compartment looks like a simple operation not requiring any special understanding until you flood the strobe for the first time.
  4. Don't pack a strobe in the camera case like you pack your suitcase to go on a dive trip. More than just your clothing will be wrinkled when you get to your dive destination.
  5. The plastic underwear (dust covers) on the flash cables will cause the O-rings to become flat and will cause the camera to flood.
  6. Connectors left connected to either the camera or strobe for a week can become frozen and break everything, including your bank account.
  7. Greasy flash contacts prevent strobe firing just like corrosion.
  8. Know how to check out your flash cable(s) just in case it became the boat guide's handle to your photo equipment.
  9. The gray side of a double flash cable is totally stupid and does not have a mind of its own. It must be told what to do by the strobe hooked up to the black side.

Note: Nikon announced the "Recall" of all Nikonos SB103 strobes on or about 10 September 1998. Please contact Nikon at 1-800-645-6687. They will arrange to exchange your SB103 (head only!) for a new SB105 (head only!!).

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Reprinted with permission from Bob Warkentin's Southern Nikonos Service Center, Inc.
9459 Kempwood, Houston, TX 77080 • 713/462-5436