Othello Tunnels - different exposure methods.

A nested series of the Othello Tunnels.

If you happen to be spending time around Hope, BC, you may want to consider checking out the Othello Tunnels.  Once a railway line, the defunct route has been converted to a pedestrian and bike trail.  The tunnels themselves are impressive but not too long; walking through any one of them takes only a short period of time.

I photographed the above shot using manual exposure mode on my camera, although an automatic mode with exposure lock would have worked equally well.  In order to get the correct settings, I established my aperture and shutter speed outside under full outdoor light.  It was important not to trust the camera's meter inside the tunnel as the dark edges may have caused the central image to be overexposed.  By metering outside and using those settings inside I ensured a correct exposure.  The inside of the tunnel would be black, but that in itself is great for framing purposes.

If I had been using an automatic setting I would have selected a scene without any backlighting or other lighting issue and then pressed the AE-L button on my camera (Canon cameras use the button marked with an asterisk (*)).  Then, going into the cavern, I would frame the shot and take the photo.  The disadvantage of using exposure lock is that, once you take your photo, the camera resets to its default settings and you have to repeat the process if you want to take another. 

There is a way to do this without moving, but it requires a little more effort.  You have to zoom your camera in to frame the outside area without the dark perimeter.  Move the camera about until you get the exposure you want and press the exposure lock button.  Zoom out to your desired focal length, reframe and shoot.  I have used this procedure when I cannot effectively use manual mode and can't get out into the zone where the exposure will be based.  It is not my first choice, but it works in a pinch.

For those of you who want to use an automatic mode but not lock the settings, you can always try bracketing.  This would involve either exposure compensation (+/- button) or turn on the automatic bracketing feature.  Three photos at 0, -1, and -2 would probably suffice.  You want to underexpose from the suggested setting as the dark values would cause the camera to let in more light than what is actually required.

Thanks for reading.   www.ericspix.com