Text and Photos by Bob Warkentin

Nikonos "Spare" User O-Rings Are Only for Specific Nikonos Products!
Don't the Spares Tell Me Just How Many O-Rings Are in My Nikonos Equipment?
Don't the Spares Show Me Just Which User O-Rings I Need to Service?
Spares Are Not for "Just in Case"
Spare Confusion or Why Use Your Nikonos As "O-Ring Test Equipment"
How to Eliminate Spare Confusion
Confusion within Nikonos Products
After-Market User O-Ring Kits Sold for Nikonos Products


Nikonos "Spare" User O-Rings Are Only
for Specific Nikonos Products!

Spare user O-ring kits are always supplied with each new camera or strobe and can even be bought separately. So why the spares? Was it to tell you that a Nikonos V camera has only four O-rings and an SB103 strobe has only three O-rings throughout the entire piece of equipment? Or are they "universal spares" for any equipment just in case you lose or damage one? Or are they just one more piece of dive equipment "junk" you must account for but never really need?

Once removed from their original bulky box, you find each kit of black O-rings secured in an unmarked, sealed plastic bag. Well, as the of saying goes, "You can't tell who or what the players are without a score card"!

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Don't the Spares Tell Me Just How Many
O-Rings Are in My Nikonos Equipment?

Seeing spares is believing, right? The most common and probably worst of all misconceptions, to which the answer is not just "No," but N!O! While the Nikonos V Owner's Manual doesn't specifically tell you the total number of O-rings in the camera body, it does tell you (1) that there are O-rings other than just your user rings, (2) that these rings need to be changed once a year, and (3) that they need to be changed professionally.

Your bag of camera spares has only four O-rings: one for the lens, one for the flash cable or flashport plug (your choice), and only two actually for the camera. But in a Nikonos V body, there are fourteen O-rings in all. Add one more to plug up the flash port and one more at least to plug up the lens hole (plus all of the other O-rings needed to make both the lens and strobe watertight!).

Photo 1

Now, think about this: with a basic setup of a Nikonos V body, 35mm lens, and SB103 strobe, you're diving with about $1,100 worth of equipment requiring a total of twenty-five O-rings, but your two bags of spares (four for the camera, three for the strobe) account for only six of these O-rings! Wait a minute! Four plus three equals seven, so why did I say only six accounted for? The camera's bag of four rings supplies one as a spare for either the flash port plug or the flash cable, and the strobe's bag of three also supplies one for the cable. You can't use them both at the same time!

I don't care if you replace user O-rings every day and grease them and care for them like a newborn baby. You, the end-user of your equipment, must understand that the user O-rings account for only one-fourth of your equipment's total O-rings. The rest must be professionally serviced!

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Don't the Spares Show Me Just Which User
O-Rings I Need to Service?

If you're forgetful or are unfamiliar with Nikonos O-rings, then by all means the answer to this question is yes! For the camera body, the most frequently overlooked O-ring seems to be the one in the battery compartment. For the strobe, believe it or not, it's the cable O-rings!

Photo 2

Use your spares as standards to jog your memory about what your user O-rings should look like (size, thickness, etc.) and just maybe where they're located. As you locate and remove each of your installed user O-rings from a piece of Nikonos equipment, simply compare them to your still-sealed bag of four, three, or whatever. Make a note (mental or written) as to which ones have been serviced in your equipment and which ones have yet to be serviced.

Try this! Photocopy each sealed kit of O-rings. Next, label the sheet "User O-rings for camera" or "for strobe" or whatever, and label each O-ring "for door," "for battery cap," "for cable" (which end), etc. Now you have an O-ring comparison (see the Caution below), and you can check-off the sheet by product item and where the O-ring is installed. You can also add the date when the camera was serviced or add other important reminders (make this your O-ring "log").

Caution: Photocopies do not generally copy 100 percent of actual size. Therefore, if you have different pieces of Nikonos equipment, or equipment of non-Nikonos manufacture, compare the O-rings first while they're still in their respective sealed plastic bags. If it's too close to call visually, do not rely solely on a photocopy as a referee. See the below sections on Marking, Sealing, and Confusion for additional tips.

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Spares Are Not for "Just in Case"

As noted in previous articles, O-rings get weak (flatten) over time, not just as a result of diving use. Do not use your "spare" O-rings sparingly! User O-rings are located in those areas of your equipment that you must open and close to change batteries, film, lenses-frequently! Each opening directly exposes the user O-rings to contamination, and the more flattening (weaker) the O-ring gets, the more likely it is that microscopic-size particles will cause leakage or flood on the next dive.

So use your spares as a full kit. Replace all the old ones at one time: at least every twelve months for the "two-trip-per-year" divers, every six months for professionals, and every three to four months for rental equipment. But even with all your cleaning and frequent full kit user replacement, don't forget you're only servicing one-fourth of all your equipment's seals! Leaks can occur everywhere there are weak O-rings!

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Spare Confusion or Why Use Your Nikonos
As "O-Ring Test Equipment"

I've seen Nikonos lenses fitted with O-rings for SB103 battery caps (the person noted it seemed a little harder to get on!), camera battery caps fitted with flash cable O-rings, and tank stem O-rings used on flash cables. Some people even use hardware or auto parts store O-rings because they're rubber, looked round and black, were close in size, and the person forgot to buy spare kits or the local camera store was out of stock. Unfortunately, the equipment all flooded!

Ever ask why when preparing your $1,000-plus-worth of equipment for diving? Ideally, you've come to realize the possibilities for "human mistakes." If you find an O-ring loose in your camera case, could it be because you keep extra regulator and BC O-rings in your camera case, or could a bag of something have come open? If an opened O-ring bag has the appropriate number of O-rings inside, maybe last year you decided to replace some, not all, of the O-rings from the new factory-sealed bag and stuffed the "old" dead ones back inside, not wanting to throw away round, black, but dead O-rings. I am sure you can add to this list of "human mistake" possibilities, but any excuses you come up with are usually dumb ones. For me, "better safe than sorry" and "when in doubt, throw it out"!

However, if you insist on using a questionable O-ring for diving, then think about what you're going to do like this: You must now consider your $1,000-worth of Nikonos equipment not as photo equipment but as test equipment for a ten-dollar set of O-rings. If it comes back dry, you've proved that the O-ring was good; if your equipment floods, you've proved it was bad!

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How to Eliminate Spare Confusion

1. Never have doubts about spare O-rings. If you've identified a user O-ring as flat or damaged, or if you just don't feel right about the O-ring for some reason, don't dive with it. Don't save it, either! Throw it into the trash the moment you question it! Don't find yourself in that unfortunate position of later saying "if only I had..." If you think you can come up with a really good reason for saving a bunch of doubtful spare O-rings, write me. I need a good laugh after all the flooded equipment I see and have to repair!

2. Mark your spare bags! I bet that if you were to look into your "O-ring hideaway" (usually it's behind the camera case lid's foam or side pouch of the Nikonos "purse") you would find that your plastic bags of O-rings aren't marked and are all opened. Well, are they really new or just old ones waiting to be recycled? What piece of equipment are they for? If it's not marked, better consider that ten-to-twelve-dollar bag as trash!

Photo 3

As soon as you buy new Nikonos equipment or new spare O-ring kits, mark the plastic bag of spare O-rings! Use a felt-tip marker, write or type a gummed label and stick it on, even use a torn piece of paper stuck on with tape. But mark what the O-rings are for: camera, lens, strobe, regulator, water faucet, car, etc! Get fancy; add the date of purchase, and if you have two or more pieces of similar Nikonos equipment, mark by serial number which bag is for which.

If you're using old O-rings for storage purposes, mark that bag specifically as "old-for storage only," and note the number of O-rings that are supposed to be in the bag when your exchange is done. Leave nothing to plain of memory!

3. Seal your spare bag! Your heat sealed plastic bag, once opened, generally can't be resealed as effectively as it once was. Therefore, I recommend zip-top bags. Use big enough bags so that the O-rings don't have to be twisted up to fit, and use those made of thicker plastic than a sandwich bag (there are many reasons why!). And mark it! So where are you going to find thick zip-top bags at a resort? Better get some as soon as you finish this article.

Let's face it, other than the need to remove your tube of O-ring grease from the sealed bag, there is absolutely no other reason to open it to remove O-rings unless you're going to replace them all, right? Well, we can always come up with exceptions. If you have several lenses or extension tubes, you may have to buy one camera kit (be it your camera model or any model Nikonos camera kit) per lens or per tube just to get one new O-ring for each. For double flash cable: either buy two SB103 kits to get the three O-rings needed or buy one SB102 kit. If this is your situation, you really have an accounting problem. Seal up the remaining unused O-rings, still as kits, and label each as "camera kit with the lens O-ring removed" or "SBxxx kit with cable O-rings removed."

I don't recommend pooling together like O-rings, even if they're marked and sealed. Leave them as kits, or throw them away. Let the kit function as a reminder of all the user O-rings in a piece of equipment that need to be replaced. If you're buying kits for equipment that you do not have just to get those O-rings that you need, then throw away or give away the remaining O-rings so that someone else will become confused-not you!

Sounds confusing? You bet it is, both in print on this page and in real life, unfortunately!

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Confusion within Nikonos Products

Different Nikonos products use O-rings that may appear very similar in size. Don't mix them up! Keep them separated as kits!

Photo 4

One prime example is the SB102 battery cap vs. Nikonos V door O-rings (see photos 3 and 4). Whether you compare them while they're still in their original kit bags or removed from their respective bags and lying side by side, they look identical. Unfortunately, they really are different, something you find out when you put your expensive equipment in water. Flash cable to strobe and camera battery cap O-rings are close in size but different in thickness. SB103 battery cap O-rings and lens O-rings have slightly different sizes but are close in thickness.

Mark every bag of extra O-rings (Nikonos or ?, and for lens, camera, strobe, etc.), and zipper them up.

Non-Nikon products may fit Nikonos equipment, but their user O-rings are not Nikonos O-rings! There are a number of manufacturers who make and sell a vast array of lenses, strobes, extension tubes, adapters, etc. to fit Nikonos products. However, just because the item fits a Nikonos camera, is water tight, and has a similar-looking O-ring, that doesn't mean the equipment's O-ring specifications have to be Nikon's! Channels, and, of course, their O-ring requirements, can be built to a number of specifications other than Nikon's and still be "Nikonos" functional.

Different O-rings
Photo 5: O-rings from different lens manufacturers.
Photo 6: Side-by-side comparison.

Face it: if the product wasn't built by Nikon, its O-rings can't be Nikonos! Buy your extras only from the manufacturer! Nikonos O-rings fit only Nikonos products, and specific ones at that!

After-Market User O-Ring Kits Sold
for Nikonos Products

From reading previous articles, you can appreciate a little of the science of O-rings. Nikon had to go to a lot of trouble and expense to have their O-rings scientifically designed and manufactured at a specific size and, more importantly, specific hardness to meet the demanding requirements for their products. For this reason, production cost is much higher than plain of standard, hardware-store-quality black O-rings.

Unfortunately, demand for spare Nikonos kits is always high while availability is sometimes limited. Therefore, camera dealers may sometimes prepare and market their own "after-market" O-ring kits for Nikonos products. Those I have seen were prepared without, it seems, proper regard for the requirements necessary in O-ring design and formulation for Nikonos use: their differences are all too obvious. I've examined some recently purchased, still-sealed "after-market" kits, and I found that, when I compared them to genuine Nikonos O-rings, some O-rings were obviously the wrong size while all were made up of the wrong rubber composition (they were just too hard).

People, buy the right O-rings for your Nikonos products (and the right non-Nikonos-product O-rings from their respective manufacturers: addresses and phone numbers for most of these are available if you want to call). Real Nikonos O-rings may cost more than "after-market" ones. But don't be penny wise and pound foolish: don't settle for just anything because you're in a hurry!


  1. Nikonos user spare O-rings are only for Nikonos brand products, and only for certain ones at that. If it's not a Nikonos product, its O-rings can't be Nikon's, nor should Nikonos O-rings be used on that product.
  2. For accounting purposes, photocopy your spare O-rings by sets and label them as to product and where the O-ring goes.
  3. Label each plastic bag of spares immediately. Once opened, transfer each kit's O-rings to a thick, labeled zip-top bag, and seal. Never combine sets or even groups of like O-rings in the same bag.
  4. Don't use spare O-rings sparingly. If one needs to be replaced, replace all within the set.
  5. Never save used or doubtful O-rings for any reason or put a used one into a bag with new O-rings. Trash it immediately before it trashes your equipment!
  6. Spares account for only one fourth of the total O-rings in your basic Nikonos system. Don't forget to have all the other O-rings professionally serviced.

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