Hereford Caving Club

As most of you have seen some of my underground images, I do get asked quite often on how I manage to get them looking good. The most important bit is lighting and where it is placed in relationship to the camera. but I will move onto this later. Firstly lets talk about cameras. All of my photos are produced using digital cameras, some more expensive than others but will all produce descent images. The advantage of using a bigger Digital Single Lens Reflex camera is the fact that it has a lot bigger sensor which will record more detail, for making bigger prints. However on most club trips underground I use a simple point and shoot compact camera with very little in the way of adjustable settings. As this type of camera only has autofocus you do need some light on the main subject of the image first. This is the biggest problem, especially if you are trying to get an image of a caver on the move, as the moment has normally gone by the time you manage to get the camera to focus on the subject.

Point and Shoot Cameras
You do not need an expensive camera to get images underground. The only thing that you do need to consider is that most P&S cameras are not waterproof and as caves are very damp places you do need to be very careful when using them underground as dampness will kill them eventually. Another thing to avoid is a camera where the lens protrudes out of the body when you switch it on as any grit/mud on this will make it stick. Although saying that, Waterproof housings are available for a lot of cameras now  but this adds more expense.
I use a Olympus MJU720SW Shock and Waterproof P&S camera. Newer versions are now available (this particular camera has been caving with me for about 4 years now and never given a spot of trouble). Other waterproof cameras are available from the likes of Pentax, Panasonic, Canon and Fujifilm.

Olympus MJU720SW with 35mm film taped over on-board flash

Using this type of camera for caving, you do need to be able to hold the ISO or ASA as low as the camera will go, otherwise the camera metering system will try and set the ISO high due to the darkness within the cave as making the ISO higher will make the camera digital sensor more sensitive to darker areas in the image. The reason for keeping the ISO low, is to stop the image coming out grainy with lack of colour depth, as it is a decent images that we are after. Using autofocus underground can also be a bit of a challenge. I find trying to focus on a caver's helmet and light seems to work the best as there is good contrast between the two which is what the camera is looking for when trying to focus. Once the camera is in focus, I keep my finger on the shutter release button and re-compose the image as required before taking the shot.
Now those of you who have already taken cameras underground have probably found that some of your images have had a lot of fog on them, especially in wet caves. This is because you have been relying upon your onboard camera flash. What is actually happening is just like driving in the fog with your high beam headlights on (onboard flash) the light is hitting the moisture in the air and reflecting straight back into the camera lens. Now if you are in a drafting passage or a very dry area this will not be a problem, although your images can look rather flat.
The way to overcome this is to use a separate light source and not your onboard camera flash. This can be as simple as a few caver's cap-lamps lighting up your subject or a separate torch. The only drawback to this is that you will require slower shutter speeds which will mean that you cannot hand hold the camera. This is easily overcome by finding a suitable placement for the camera (either a mini tripod or a boulder) then set the self timer. This is so that you do not accidentally move the camera by pressing the shutter button. Also using the self timer will give you chance to autofocus on something press the shutter button and have time to reposition the camera to take the shot before the shutter opens (all good fun). Another cheap form of lighting is a standard camera flashgun which you can pick up from charity shops or on ebay for a bout £10. If you take this route, try to buy one which has a test button, otherwise you will have to find a way to short out the two contacts on the base of flashgun in order to fire it. With this flashgun you can then fire it as soon as the camera shutter opens. If your camera has a Nighttime Mode on it, then use this as it will give you about a 3-4 second exposure which is plenty of time to fire a flashgun. This is all fine as long as your camera is mounted solid and your subjects are not moving ie. formations. However if you want to take a photo of caver's in action, then you need to be able to handhold the camera to compose the shot and of course you will need flashgun that fires independently. This is where a bit of expense comes in, as you will need a Firefly 3 to use with this type of camera.

Left - Firefly 3 available from http://www.fireflyelectronics.co.uk/Index.htm

The reason for using a Firefly 3 as opposed to a Firefly 2 is because most P&S cameras send out a pre-flash to check exposure before firing the main flash, and the Firefly 3 is programmed to ignore this pre-flash and only fire the flashgun on the second, main flash. A Firefly 3 is a slave unit which you connect to your remote, cheap flashgun, then you need to cover over the front of your on-board camera flash with a bit of old exposed 35mm film (this will come with a new Firefly). I just stick mine on with a bit of clear tape. With this all fitted when you use your camera and the onboard camera flash fires it will only allow infrared light through this film activating the Firefly 3 which in turn will fire the flashgun remotely. Now this will greatly improve your underground images as you are now able to put the lighting where ever you want, plus as the light source is away from the lens. You will not get any foggy images, no matter how moist a cave is.

Compact Cameras with full manual control.
This type of camera is one up from the P&S camera but does offer a lot more possibility’s for being more creative. At the time of writing this, no manufacturer has made a waterproof version of this type of camera (if they do then a lot will be sold for caving), so this type of camera has to be used  in a waterproof housing. I use a Canon G7 as it has manual focus and a reasonable zoom plus full manual controls, meaning that I can set the camera up on a tripod and open the shutter and leave it open for as long as I want firing flashguns. This is useful when you want to light up a large area. Also I can use a Firefly 2 as the onboard flash and can be set to manual (Firefly 2 is half the price of a Firefly 3 as it does not need to ignore the pre flash). Plus, with manual focus you can get up very close to small formations or the end of a straw to get some nice close up shots. Finally we also get a histogram on the back of the camera screen which can tell you how well the image has been exposed and if you need more or less light (this is very useful tool underground, as looking at the images in complete darkness will give you false results).

Digital Single Lens Reflex Camera
Now this is a big camera, and not really suitable to taking on a normal club trip, but the benefits are similar to the Compact Camera with full manual control, with one added benefit. The size of the sensor inside the camera is about double so a lot more detail can be recorded resulting in being able to produce large sharp images with lots of detail and good colour. Als,o of course you have the option of interchangeable lens (although it’s not recommended to change whilst underground). However the one disadvantage is that they are not waterproof. Although saying that my Nikon DSLR is very well sealed, so you just have to very careful in where you use it. I transport my DSLR camera in a ‘peli case’ which is very robust and waterproof.

Lighting
As we are working in complete darkness, all lighting is controllable and this can make or break your image. Do try and experiment with your remote flashgun and you will see just how much it can alter the look an image. From experience I have found that bringing light in from right angles seem to give the best results, as shadows will appear on a uneven surfaces which will give the image more depth. Or, if you are lighting up straws etc. above you, then I find lighting from behind them works well.

Left - diagram showing camera in relationship to flash and formations (subject).

                Returning back to our P&S cameras, where you have no control over exposure, this can be adjusted by repositioning the flashgun. If your image is far too bright, then slightly turn the flashgun away from the subject and try again. It is all trial and error until you get a bit more experienced with the power of your particular flashgun.
But do remember when reviewing your images on the back of your camera, be it a simple P&S camera or a DSLR, you are looking at them in very dark conditions so they do need to look very bright. Otherwise when you get home and look on the computer screen they will appear dark and underexposed.

Finally posed shots just do not work! I have tried and you can always see that it is set up. I now find that I just take the shots, whether I get what I intended or not. When I do get a good image, then I must admit I am very pleased.