"The best camera is the one you have on you" - and this is true for caves as well. Do not be afraid to use what you do have access to, play around with lighting, and learn about framing. Almost all locations on Earth have light; underground is one of the few exceptions and so the lighting is often the most important component, in some ways more than the camera itself. These days, LED technology means great lights are on everyone's cave helmets, and so using SIT (sustained illumination technology) or light painting is in everyone's reach who has a phone on their camera.
All of my first cave photographs were with a cheap HP point and shoot digital camera that I had at the time, so think decades old technology with decades old light tech. Were they the best? Nope. Did I learn a lot? Yes. Does spending just a minute or two thinking about lighting give you better photos than most will take? Yes. Get the light off of your camera, whether by flash or by headlamp, and your results will be MUCH better, instantly.
A photo I took over a decade ago of some formations in the UK. Spending two minutes on this photo using a friend's helmet light made it 10x better than just using the on-camera flash. I see many flaws with it now, but back then, it was the first cave photo I was ever proud of.
My Requirements for Cave Cameras
I hate heavy packs and bulky gear. Small and light. I never wanted to use a SLR setup underground - have you ever lifted someone's cave pack who carries one? Eesh! I use a Pelican 1120 case and my entire setup has always been under 3 pounds; this fits in any standard daypack with ease and is easy to maneuver around, even in crawls. For a lens, I want a wide angle (20-30mm) as many areas underground are smaller. Fast lenses that let in lots of light are best so I don't have to boost ISO too much which leads to grainy images and loss of detail. (Pro tip: don't buy into super high ISO marketing, especially on any sensor smaller than ASP-C.) A hot-shoe is a must for using off camera flashes. Ideally, with the bio-work I do, I want the ability to take macro images of cave life on short notice without changing lenses. This is a lot to ask for in a small package. Very few cameras have this level of quality and flexibility, even if money is no object.
A lot of research brought me to this little amazing camera, which is based off a Leica camera, having the same high quality glass but without the expensive name attached. It has a very fast lens, f/2.0, which on a smaller sensor actually still gives amazing depth of field. The lens is wide (22mm equivalent) which is wonderful for cave photography. The design of the camera dials tend to keep dust out, so unless you're in waterfall mist it holds up well underground. The best part? Even in 2011 I could get them used for a whopping $100. Now you can find them under $50, if you can find them for sale. It is such a well liked camera that dpreviews in 2017 made a "throwback thursday" post celebrating it: the LX3 made a new standard for the compact class, providing good manual control and good glass and even a hotshoe.
I shot for about a decade on the LX3. The majority of my cave photography even things published by NatGeo, photos that won and placed in competitions from Alabama Outdoors to Hidden Earth, and more, all from this teeny little workhorse of a camera. Most of the images on this site are still from this camera as I shot with it for so long.
Everything from classic TAG pits...
Internationally famous classics in Mexico...
Trips to the UK....
Huge chambers in Spain...
Macros of teeny tiny invertebrates...
and stunningly colourful mines!
The above photos are sometimes light-painted, but mostly flash photography. I use Yongnuo triggers (thanks to Footleg for that suggestion!) and a $5 flash I found at a thrift store that is nicely bright, but not a fancy or brand name one that has all the features people want for modern dSLR, hence, the price. I have yet to break that flash and it's over a decade old with cave use now. I do light painting with a 'sodacan' 3000 lumen light, but they come far brighter now than they did 10 years go. Plus, the average Zebralight or other cave-specific light people use on their helmets will do fine as these have pushed lumen barriers with modern LED technology that did not exist readily before.
The LX3 has great image quality at 200 ISO, good and easily smoothed at 400 ISO, and can be pushed to 800 without much detail loss. The f/2.0 lens means a lot of light is allowed in, and so it is just...easy...to get good photos in low light. I find it natural to use and not a struggle. It finds auto-focus well, or you can manually focus without difficulty. The hot-shoe allows the trigger attachment for off camera flash, something most small cameras do not have, and something I highly recommend for cave photography.
I find the LX3 lasts a few years underground, and I still keep one around to use as a backup. The only thing 'wrong' with it was my personal photography style was growing beyond the now-over-20-years-old technology. But, for example, a trip two weeks ago I didn't have my current camera working so I grabbed my LX3 to take, and it did the job wonderfully as we explored a section of a system not visited in 30 years.
For a few months in 2013, I tried the Lumix LX5, the upgrade from the LX3. It died pretty quickly in the cave environment due to the new dial layout and dial types. It also was harder to focus lock correctly. So although it offered an upgraded lens and on paper better abilities, I found it to perform slightly worse than the LX3 underground. The final images were comparable (see below), just harder to achieve, and it didn't handle the cave environment as well. Because the LX7 had the same dial/control layout as the LX5, I never tried it, but I would expect similar regarding it not holding up as well against dust and moisture.
The new-and-improved line of LX cameras: the LX100 is a compact micro 4/3 camera, with updated abilities and controls with a stunningly low aperture of f/1.7, and a 24mm equivalent lens. It is a leap forward from the other LX cameras and when I realized I was outgrowing the LX3 I had to try it. It has been almost two years, and I really like it. I can push the ISO to 1600 if I really need to, but it is nice straight out of the camera up to 800. It is not as good at handling the cave environment as the LX3, but far better than the LX5. Dust getting into the lens retraction mechanism is well documented, but there is a fix involving a vacuum cleaner (yes, literally sucking the dust back out when it starts to get sticky, it works, I've done it). Because compact cameras have retracting lenses, dust *will* eventually gunk them up. Just a fact. I still love them because I do macro when I see neat invertebrates during bioinventory work, and they have a nice wide lens which works great in cave photography. If you can afford the $350 for a used LX100 I would recommend it! (If not, stick to the LX3 for $50!)
Here are some photos from my LX100; they may look very similar to other images, but they were easier to achieve with the new lens and larger sensor and - while you cannot zoom in here - looking closer at the original image files there is a difference especially in noise handling and sharpness.
Slowly I am tiring of lens retraction issues. They are annoying, especially when it gums a camera up mid-cave-trip! Mirrorless compact system cameras have come a long way in the last decade, so after a lot of research I settled on the Sony a6300 because it would fit in my existing tiny 1120 pelican case without upsizing, it has some dust & moisture resistance (albeit not that great, Sony notoriously oversells their weather sealing), plus - all the amazing reviews - including low light functionality. I would lose macro abilities but with an ASP-C size sensor, I reasoned I should be able to crop to almost as good as a full macro was on the Lumix, especially if the image quality and sharpness were as good as reviews claimed.
I purchased it with two 'pancake' lenses and gave it a test run in my backyard, checking out the focus lock settings and even found a fly wing to practice some "macro" with to see if I could indeed crop it heavily and have a great image. It looked promising, all was working well and the fake-macro test worked adequately. Next step - check it in a nice clean cave. I was in for a shocker.
The first thing I noticed was the display. It was black. (And so was the viewfinder.) This was shocking as I have a very bright cave headlamp, so there's no excuse for the screen preview to be black. I have never had that issue on any camera I have ever used underground. Did I take off the lens cap? Yes, I had. Weird! I finally figured out that some light bounced off the pole in the frame making it barely show on the display, so I focus locked on it. Press the shutter button. Snap!
Nothing happened. Well. I did have a completely black image; no flash fired.
I tried again. Same story.
I went over to make sure the flash and triggers were on, and the triggers were talking to each other: the test button worked fine.
I tried again. Nothing happened.
I ended up pulling the trigger off the Sony camera and manually firing it (setting the exposure to 1/5 sec and just pressing the trigger right as I clicked the shutter). This worked, the flash went off every time.
We have images! However, the focus was VERY off.
With about a dozen shots, all the same thing by the way, ONE came out mostly focused, enough to pull some sharpness in post so it didn't look that bad. Most of the shots were horribly out of focus, a total blur. As the focus lock worked above ground, this means it wasn't finding focus in the 'low light' of the cave with over 1000 lumens of light. Plus, it's hard to frame when you have basically no visual on screen, only a faint outline of a pole (so, I know the screen was *working* - and again had I checked above ground).
I know you are wondering, so here is the photo:
Nothing complex, nothing hard, plenty of water for light to bounce around...and yet...nope. Most were a full out blur.
A bit of research revealed that Sony does not play nice with others (worse than Apple) and triggers won't work without a soldering modification. Unless I want to buy expensive Sony triggers, of course. This cascade of issues meant it was obvious to send it back. While some may say, "You just have to learn this camera!", I can't help but feel it shouldn't be this difficult. Plus, remember, it worked above ground just fine for all of my pre-cave-tests. Therefore, I had to conclude it was the cave environment and types of lighting styles I use in cave photography that it is not compatible with. I cannot compose photos with a black preview screen. I cannot create images if the camera cannot focus. I also need my flash triggers!
Panasonic Lumix all the way. I will happily use a $50 almost 25 year old LX3 than a new Sony alpha.
I am very happy with the LX100, and with the version 2 released, prices continue to drop, so I have a feeling it will continue to be my cave camera for a some time to come. The only other small/compact cave cameras I have enjoyed when borrowing friend's cameras were other Panasonics, even some of their micro 4/3 system cameras; the Panasonic GM5 was the tiniest micro 4/3 system camera ever built and if I can ever find one of my own, I will get it! There is just something about their builds that simply work for caves.
Panasonic GM5 with pancake prime lens, borrowed from a friend in Spain for this photo.
If only they were still made...that combo was smaller than my LX100 is!
SLR's for Underground
If the weight of a larger system is not bothersome, then I highly recommend Pentax. Their weather sealing is matched by none, and their lens options that are *ALSO* weather sealed are fantastic (as are their non-sealed lenses) and will not 'break the bank'. I use Pentax above ground where for me size & weight is not as much of a factor. I have even prompted many photographer and cave-photographer friends convert to it. Their price points are much better for their features than other brand names; a nice brand new weather sealed set up will cost ~$700, less for used. I have (accidently) literally dunked Pentax in a lake, fished it out, and it was 100% fine. I've used it in rain/snow/freeze storms in Iceland. I've used it in waterfalls. Never an issue and as good as the day I got it. You do have to watch out for the K50 and K70 aperture control issue, so I recommend against a used one of those. On current model lines, the KP is a great budget choice.
No issues in this deluge of a flooding streamway crawl! Purposefully for this shoot I used Pentax due to the extreme wet conditions.