About my Underwater Digital Still Camera
About Underwater Digital Still Photography
Tips on using the Coolpix Underwater
A Picture of my Camera and Housing
Summary:
These pictures were taken with a Nikon Coolpix 950 in an Ikelite housing, using a Nikon SB-105 strobe (photo). The setup is great for underwater photography - the 64MB card allows for 133+ photos on a single "roll" of digital film, and the NiMH batteries can just about handle that many (the most I've done is 90 pictures on one dive). The immediate results make for great fun for the other folks on the boat. And Photoshop can clean up a great many mistakes.
Ikelite was the first company I found that came out with a housing for a digital still camera. It retails for $950; you can visit Ikelite's website for more details. It's the usual plastic-box style Ikelite housing, but seems reasonably well executed. I've had it on about 30 dives with no problems. My main complaint is that it's much bigger than necessary; compared to my Mako video rig from Light and Motion it's pretty clumsy. But then again it costs less than a quarter as much.
The strobe cable is brought out to an Ikelite style connector. Ikelite now sells an Ikelite to Nikon cord, which works great..
Being nearsighted (I had LASIC done a year ago), I can't really tell from the viewfinder if the picture is in focus, nor read the settings. I tried to put some fresnel lenses from Edmund Scientific into the housing to improve the situation, but the focal lengths and sizes available didn't work out. Instead I use a single stick-on 3 diopter bifocal lens in the right eye of my mask; now that I'm used to it I'm happy with this system.
The only real "bug" I've found thus far with the housing is that the arm that presses the focus and flash buttons can get caught under the shutter arm when the back is sealed, rendering the camera useless underwater. Fortunately it doesn't cause a flood when this happens. That's on my pre-dive checklist now.
For night dives, I attach one of the Light and Motion "Sunray" video lights from my Mako. I made a clip out of stock aluminum extrusions for the Mako battery pods which attaches to the bottom of the Ikelite grip. This works great.
Ikelite recommends using a video light with the Coolpix. After talking to the folks at Backscatter, I decided I wanted the effect a strobe would give, and decided to try the Nikon SB-105. I've been pretty happy with the results. Probably I'd get even better pictures with two strobes, but one of my own goals a camera that's small enough that it won't spoil your dive if for some reason you decide not to shoot pictures. The SB-105 can fire about 130 full power shots off a set of 1500 mAH NiMH batteries. That's plenty.
One advantage of the Coolpix 950 is that it has an external TTL flash. But it's not really true TTL; there's a sensor next to the lens that detects the reflected light level. Fortunately, the Ikelite dome port is big enough that the sensor can see out, and TTL works, sort of. Note that if you use the wide angle lens for the Nikon, the sensor is blocked and you can't use TTL flash. Underwater, I frequently get over-exposure when using TTL. In that case, I just switch to a manual strobe setting (easy on the SB-105) and shoot again. I keep it on TTL when I'm cruising; that way I tend to get a reasonable exposure on those "quick - take a shot" frames. Being able to have LOTS of shots on a virtual "roll" of film and getting a preview of every shot as you take it makes the unscientific method of shooting and adjusting exposure afterwards really quite efficient. And of course you get good at guessing what works and what doesn't.
I've tried several times to take pictures using natural light using the Coolpix, and it just doesn't seem to work. There's just not enough light underwater to get a fast enough shutter speed and small enough aperture. All the photos using natural light seem a bit blurry.
There are a handful of really good things about the Coolpix 950 that convince me it's the best digital still camera available today for underwater use, but there are also an awful lot of really dumb things about the camera that could easily be improved. I also have an Olympus C-2000, which I prefer over the Coolpix for surface shots.
The good things about the Coolpix 950:
TTL Strobe: While I originally thought this was really important, the fact that it only sort-of works with the Coolpix leads me to conclude it's really not that important. It doesn't work at all with the wide angle lens, and it really doesn't work right with the manual aperture mode (although this can be used to advantage).
Programmable shut-off time: You can program the time which the Coolpix 950 stays on between shots, before it decides you really don't want to use it and automatically powers off. I set this to 30 minutes. A set of 1500 mAH NimH batteries lasts about 1.5 hours in the Coolpix with the display on, so I can leave it on throughout the whole dive and never worry about missing a shot because the camera went to sleep. This is really important.
Memory of previous modes: The Coolpix remembers that it was in macro mode, and that it had the flash turned permanently on, two modes that I nearly always use. So if I need to turn it off, I don't have to go through all kinds of menus to re-set the thing to the desired state. It also remembers that it is using the external strobe (important since the internal strobe is blocked by the housing's dome port rim).
Superior Macro Mode: The Coolpix can focus down to a couple of centimeters away from the lens; you can practically touch the dome port to the subject.
The bad things about the Coolpix 950:
These are a handful of fairly annoying things that you might want to look for as new digital still cameras become available.
Lousy Auto-focus: The Coolpix frequently fails to find focus. About the only thing you can do when it loses it and can't recover (which happens many times during a dive) is to zoom out to wide angle and back to mid-range again. The reason you can't stay at wide angle is because the macro mode requires that you be about mid-range in the zoom. Another problem is that it will lock on any dust inside the dome port (another checklist item). Finally, when you power the camera on, it initializes to a state of nearly fully telephoto. The first thing to do is back off to wider angle.
Shutter Delay: The Coolpix has an apparent delay of about a second from when you snap the shutter until when the picture is taken. When I first started using the camera, this drove me absolutely nuts. I'd snap the shutter when the fish was facing me, only to see the flash fire about a second later after the fish had turned away. By practice shooting a stopwatch out of water, I learned that this happens because the camera needs to autofocus before firing, and until you press the shutter it fails to do the final autofocus step. So the key is to partially depress the shutter (you can see you did that because the display dims) and then press the rest of the way when the fish is exactly in position. This reduces the delay to a tolerable 0.2 sec.
Operating System Crashes: Twice during dives I've had the camera fail because the operating system in the camera crashed! The first symptom is that pressing the shutter doesn't take a picture, next that other controls begin to fail to operate. Then the zoom control fails, and after that even the on-off switch won't work! You have to pull the batteries out to recover. End of pictures for the dive.
Poor Manual Modes: The Coolpix specs make it appear to have lots of manual controls - aperture and shutter priority in addition to fully automatic, manual focus, etc. But they are really hokey. The aperture priority has three settings - f2.8, f5.6, and f11. Manual focus has settings of inf, 30', 10' 5', 3', 1.5', 1', 8", 4", but in order to use it you need to hold down the manual focus button while simultaneously turning the knob on the front, which is practically impossible underwater. A pushbutton increment/decrement would be most useful. And finally, there is no way to actually fully control the exposure - no true manual mode. You can tell the Coolpix to deliberately under or over expose by some number of stops, but you can't say "make it f11 at 1/100th. Also, none of the manual modes have any effect on the TTL circuit - you can't fix the systematic over-exposure of TTL by asking for a couple of stops of underexposure.
No easy way to delete shots: Deleting the last shot requires switching to play mode, pressing the delete button, then confirming the deletion by pressing a menu button and then the shutter. Why not just a simple (maybe 2 press) delete immediately after the shot? I think if you're REALLY quick you might be able to do it while its displaying the shot right afterwards, but I'm too busy evaluating and thinking (and too narc'd).
Stupid shape: The Coolpix could fit in a much smaller case if it didn't have the silly "twist" industrial design. The "twist" makes for another failure mode - if you tilt the lens half of the camera when you insert it in the housing, you can miss dead center on the dome port and warp all your shots.
But enough ranting and raving - the bottom line is - I still love it!
About Underwater Digital Still Photography:
The best thing about digital still photography is the immediate gratification. I can see my shots on the big screen of my laptop minutes after the dive when I'm on a live-aboard, and at the car when we're diving locally. I can email them to dive buddies right away; I can give a slide show at the end of the trip or even the end of the day. My son Nick, who is just learning about underwater photography gets immediate feedback on what he's doing wrong, and what he's doing right.
The reason I originally bought the camera was to supplement my video work. I can use a still shot as a title, and can even pan and zoom on the shot. Since the still camera has far better resolution than the video pixel count, this works extremely well (though I have yet to complete a production using it).
I've just bought the new Epson 1270 printer. From a good full frame shot, I can make an 8x10 print that is essentially indistinguishable from a 35mm print. I think I can take the very best shots up to 11x14. This is close to what a 35mm can do. I'm currently planning on skipping the 3M pixel generation, and upgrading when 4M pixel cameras become available.
Tips on using the Coolpix Underwater:
I heard recently that I've had comparatively good results with the Coolpix in the Ikelite housing. Here are some tips that might help others:
General Underwater Photography Tips:
1. Take LOTS of pictures. This is particularly easy with this rig since you've got over 100 shots per dive. Delete bad shots later. Bracket exposures, change angles and lighting. Never even think about whether a shot is worth taking or not.
2. Think about composition when you shoot. The resolution is limited enough that a (nearly) full frame shot looks noticeably better than one that's significantly cropped.
3. Shoot at nearly maximum wide angle to minimize the amount of water between lens and subject.
4. Close-ups (macro) in particular are easy and spectacular with this set-up. Keep an eye out for stuff that would look neat when viewed very close.
5. Plagiarize! Look at stuff by other photographers more talented than us, and copy and adapt the clever ideas.
Equipment:
1. Use 1500 or 1600 mAH NiMH batteries (Quest or MAHA brands). Olympus makes a universal voltage NiMH charger; I haven't found any other sources for one (even though I like the chargers from Thomas Distributing better, they're inconvenient for travel since they require different transformers for 115 and 230 mains.)
2. Use a 64MB card in "normal" quality (133 shots).
3. Don't bother with the wide angle adapter for the Coolpix; it blocks the TTL sensor.
Setting up the Coolpix 950:
1. Use it in REC-M mode, not REC-A. This is necessary because in REC-A you can't use the external strobe.
2. Turn the strobe permanently active.
3. Always keep the camera in MACRO focus mode. The camera still seems capable of focusing out to infinity.
4. Set the exposure to aperture priority (A) at an F11 stop when the camera is mostly telephoto. This is F7.4 at full wide angle. This is really important. If you use shutter priority or normal mode, the aperture gets set to minimum (F2.8) always in the low light underwater, and the depth of focus is lousy. Also, this seems to help the autofocus work better.
5. I'm experimenting with this, but it seems like a good idea: Set the camera to underexpose by a stop or two. One of the problems with the Coolpix is that it operates with shutter 1/30th when wide open in aperture priority. If there's enough ambient light, this causes blurring of the strobe image. Because the underexposure control doesn't affect the TTL metering, you can use it to reduce the ambient exposure when the light is bright. In Monterey, it's probably not so necessary, but in the tropics there may be enough ambient light at depth that this will make a difference.
Checklist (What I've done wrong refore):
1. Make sure there's no dust on the inside of the dome lens port.
2. Be sure to take the lens cap off the camera before putting it in the housing.
3. Make sure the RAM card is empty (133 pictures available).
4. Make sure the camera has fresh batteries. The battery low indicator won't give much advanced warning.
5. Make sure the flash cable is fully seated and screwed into the camera.
6. Make sure the lens side of the camera body is horizontal, not tilted.
7. Make sure the flash cable is routed properly inside the housing, not pushing the camera or holding the housing back slightly open.
8. Visually inspect the main O-ring around the Ikelite backplate just before snapping it down.
9. Check all controls to ensure they are free, not jammed in any way.
10. Make sure both ends of the strobe cable are fully seated and screwed down tight.
11. Make sure the strobe has fresh batteries. Test fire the strobe in "full" power mode and watch the recovery time to be sure it's a full charge.
12. Check the REC-M settings are Flash ON, Macro mode, Aperture Priority.
13. Take of the Red dome port dust cover just before entering the water.
I'm a Photoshop user (though I still have a lot to learn), but I agree with others that Photoshop can make a mediocre underwater photograph spectacular. The photos produced by the Coolpix have more latitude than I expected - you can compensate for a remarkable degree of overexposure. And of course you can remove a lot of annoying backscatter. And for those of you who are environmentally minded, you can create a photogenic scene without having to handle (and potentially damage) the invertebrates.
Having 133 shots on a "roll" may seem like a lot, but I find it incredibly useful. I never worry about if a shot is worth taking. I don't bother to delete even complete mistakes underwater. I shoot a subject from every angle and lighting condition I can think of. And while I'm a light breather (generally my dives, even in Monterey, are an hour or more) I have yet to run out of shots or batteries on a dive.
I think underwater digital still photography has so many advantages that it will soon become the dominant format for amateur underwater photographers. Two things I'd love to see in future cameras - compactness and reliability. Compactness should be easy - a camera with a form factor like the Olympus C-2000 could be fit snugly into a tight housing and carried in a BC pocket! The only thing that will prevent this is gimmicky industrial designs like that of the Coolpix.
Because the medium is electronic, achieving incredibly high reliability should be easy. There's no reason that ALL the controls on the camera couldn't be controlled via infrared remote. You could put the camera in a practically permanent housing (no O-rings wear) with a separate compartment for batteries. Control handles (a la the Mako) could communicate via IR to the camera, and the data dump could also be via IR back to the computer. No moving parts means super-high reliability.
Of course, a true TTL flash and complete manual control would be welcome features. Also, it would be great to find a way to make the viewing screen really big (could you use an LCD television?).
Being an electronics engineer, I'd be happy to work with anybody inclined to solve these problems who's capable on the mechanical side.
Comments/Feedback/Suggestions are welcome. I'll do my best to answer email questions too.
--dave R
A Picture of my Camera and Housing
The camera in the housing, set up for a night dive. The batteries at bottom are attached via my home-made bracket, and power the video light at top left. For daytime dives, I just use the plastic housing, black handle bracket, and strobe.