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Nikonos IV-A
35mm Underwater Camera (1980-1983)

Intro   Specs   Performance   Usage   Recommendations

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Nikonos IV-A

Nikonos IV-A (35mm coverage, 58mm filters, 34.1 oz./968g, with film, batteries and strap lugs, 2.75'/0.8m close focus, about $75 used). enlarge. I'd get it at this link directly to them at eBay (see How to Win at eBay).

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Nikonos IV-A

Nikonos IV-A.


August 2015   Nikon Reviews   Nikon Lenses    All Reviews


Introduction         top

Intro   Specs   Performance   Usage   Recommendations

Adorama pays top dollar for your used gear.

B&H Photo - Video - Pro Audio

I buy only from these approved sources. I can't vouch for ads below.

This is the classic Nikon underwater camera. It's built like a tank and needs no additional housing for depths to 160 feet (50m).

It has interchangeable lenses. The most popular lens is the 35mm f/2.5 which may be used on land, sea or air; in fact, this is a great camera for use in dirty, dusty and wet environments.


History and Models



TTL Flash?
1963 - 1968
Nikonos II
1968 - 1975
Nikonos III
1975 - 1980
Nikonos IV-A
1980 - 1983
Nikonos V
1983 - 2001
Nikonos RS (SLR)
1992 - 2001

The Nikonos (Calypso), Nikonos-II and Nikonos-III looked like traditional black rangefinder cameras and had slightly trapezoidal bodies. Their finders didn't pop out above the body as they do on the Nikonos IV-A and Nikonos V.

The -A of the Nikonos IV-A signifies new automatic exposure, and the large finder extends above the top plate of the camera.

The Nikonos V added TTL flash, orange or green outside rubber and shutter speeds indicated in the finder.

Lenses are interchangeable among the Nikonos, Nikonos II, Nikonos III, Nikonos IV-A and Nikonos V.

Nikon's only underwater SLR was the Nikonos RS of 1992 - 2001, which uses different lenses.


Specifications         top

Intro   Specs   Performance   Usage   Recommendations


These are as I've measured or guessed.



The 35mm f/2.5 and 80mm f/4 lenses work in water and air.

The 28mm f/3.5, 20mm f/2.8 and 15mm f/2.8 lenses only work under water.


Standard Lens

35mm f/2.5 works on land, sea and air.

6-bladed manual diaphragm stops down to f/22.

Focus from infinity to 2.75' (0.8m).

Filter thread appears to be 58mm.


Filter Size (Standard 35mm lens):

58mm screw-in.



Scale focus only. Guess or measure (tape) the distance and set it on the dial. There is no rangefinder. I'm unsure if the distances correspond to water or air.


Depth-of-Field Scale

Magic moving indicators move along the distance scale as you change the aperture.


Exposure Dial Settings

Aperture-preferred Auto (A), Mechanical 1/90 (M), Bulb (B) and (R) for rewind.



25 ~ 1,600.



1/30 - 1/1,000 on Auto, I think.

When tested it seems to be able to go for many seconds at night, an excellent plus. My Nikon FE of this same vintage could exposure perfectly for many minutes at night.


Flash Sync

Via a three-terminal connector under a screw-tight cover on the bottom plate.



Thumb wind and rewind.

Two S76 button cells for meter and shutter.


Power Switch

I can't see any.

The finder LED goes out by itself.


Viewfinder Indications

One red LED explained under operation.



34.125 oz. (967.5g), with film, batteries and strap lugs, no strap or case, measured.


Performance         top

Intro   Specs   Performance   Usage   Recommendations


We'll see when I get the film back!

The shutter release is lovely: one smooth, long actuation releases the electronic shutter.


Usage         top

Intro   Specs   Performance   Usage   Recommendations


Easy: there are only four things to set: film speed, the shutter, focus and aperture.


Film Speed

Film speed is set on the left dial: lift and turn. Film loading is by flipping open the back and the pressure plate. Unlatch the back on the left by turning the O-C knob to O (Open).


Shutter Dial

The four shutter settings are around the wind lever on the right: A, M, B and R. Leave it on A, automatic. M is a mechanical 1/90 setting for when your batteries die or for flash. B is Bulb for long exposures (why?), and R is for rewinding the film.



To rewind, select R on the right dial, then lift and turn the rewind crank on the left side. Rewinding is clockwise as marked on the crank. Open the back, remove the film and then rotate the crank backwards (counter-clockwise) to push it back in.

Nikonos IV-A lens

Nikonos IV-A Focus and Diaphragm Controls



Set the focus distance by twisting the silver knob. Guess or use a tape measure. Depth-of-field is shown by the two red pointer which move as you set the aperture.

If you set the infinity mark to the red dot as shown above, you ought to have everything from the distance at the other red dot (6' or 1.8m in this example) in focus.

This distance scale is calibrated for air. If you use a tape underwater you'll need to correct it.



Set the aperture (diaphragm or f/stop) with the black knob.



Tap the shutter lightly and a red LED appears in the finder. If the red LED stays lit, exposure is correct and in the range of 1/1,000 to 1/30.

If the red LED blinks, exposure is over or under this range, so adjust the aperture until it becomes steady.

In dim light the exposure ought to be fine even if blinking, but the picture may be blurred from a long exposure. Hold steady or use a tripod.



I have no idea. I don't use this underwater. People who use underwater cameras love to brag about the expensive gear they flood. Get one tiny spec of grit on the O-ring and you're dead.


Lens Changing

Thee is no bayonet lock to release, just a detent.

Twist the lens body 90 degrees until the silver knob is in front of the finder. Pull out the lens.

To replace a lens, put the silver knob in front of the finder and push in. Rotate 90 degrees until it's back as shown above.

I point the camera down so crud falls out, instead of into the focal plane shutter.

Underwater users pay close attention to the O-ring seals and grease. I don't know these procedures.


Recommendations         top

Intro   Specs   Performance   Usage   Recommendations

This was a gift from Daniel in Sedona when he discovered that no one wanted this camera. Strange, but true. Today of course it only shoots film, but gosh, this is a sealed, waterproof, crap and crud-proof solid brick of a camera perfect for shooting anything that might shoot back or be messy. Try it in the surf!

Oddly the one I was given has some green corrosion on some of the chrome. What? This is an underwater camera - how on Earth does it corrode? It lives underwater! People tell me it corrodes when people forget to rinse it in fresh water after using it in salt water.

If you've found all the time, effort and expense I put into researching and sharing all this, this free website's biggest source of support is when you use these links, especially this link directly to them at eBay (see How to Win at eBay), when you get anything, regardless of the country in which you live. Thanks! Ken.


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June 2007