Cave Photography

• Film: Avoid slide film. It's useable, but negative film is much more forgiving. In particular, lower speed films [100 ASA] are more forgiving than 400 ASA. The faster a film is, the more it stretches the contrast of the pictures. Faster film is also grainier. I've used push-process 1600 ASA (really 400 ASA pushed to 800 or 1600 ASA) and it works wonderfully, but expect the contrast to be harsh, the grain to be visable and colors to shift in some cases.
• Camera Lens: I'd suggest something < 35mm, ideally 28mm or even less! Unless you are in a very large cavern a 28mm lens is a must. The spaces are simply too small. In this regard point and shoot cameras are usually very good as they have wide angle lenses. However, they do tend to have severe distortion at the edges. I find my 32mm point-and-shoot [built in flash] to be handy, but it doesn't really give me enough of a view.
• Bracketing: Bracket your shots. If you calculate that a 8 second exposure is what you need, then try shots at 4x and 1/4x [ie 32 and 2 seconds] the exposure. Film is cheap compared to going back into the cave! Negative film will usually forgive you 2 stops or 4x in speed before the image quality severly degrades due to over / under exposure.
• Flash: A flash is only good for relatively close formations. Things too close to the camera will be washed out and those more than a handfull of yards / meters will be very dark. But this is often the only thing that you can use on guided tours and they often don't allow the use of tripods or even monopods. The Great Basin National Park (USA) pictures were taken with a flash.
• Candles: Yes you can use candles as a light source. In my West Virgina cavern pictures you will see what a 60 second exposure time does to candles and headlights.
• Equipment: Tripod, extra film and practice changing it quickly so that you don't get dirt into the camera body, shutter release so that you don't have to hold the shutter button.
• Exposure Times: If you're not using a flash then you'll have to take a stab at exposure times. In large caverns using a 28mm lens at f 3.5 I used exposure times of 60 seconds using the 20W halogen bulb I have.
• Illumination: I've used a 20W halogen flood light for illuminating caves for pictures. This light is focused over an arc of 45 degrees. So, it will give the same illumination as a 500W light bulb that is flooding light in 360 degrees.
  When trying to photograph larger caves, it will help if you "paint" the wall with your light and so spread out the illumination. The West Virgina cavern pictures show 60 second exposure time with 100 ASA film at f 3.5 with the 20W lamp.
• Condensation on lenses and fine dust can be a real problem. Keep your camera in a well sealed bag, or better yet several bags inside each other.
• If you've got the batteries, the one thing to do is to use a bank of flash bulbs and leave the shutter open while you point the flash bulbs at different walls. ie. simply use multiple flashes to get enough light onto the film.

Caving Light

Here are pictures of my caving light mounted in the ABS tube:

For more information check my bike light web page.

Useful Cave Links

• Breakdown Bob's web page has excellent photos and information about cave photography
• District of Columbia Grotto (list of closed or partially closed caves)
• Caving Canada
• Toronto Ontario Caving Group