Campfire Cooking: Lesson Two

Campfire Potatoes

This meal pretty much cooks itself - just leave it in the coals! Be sure to count how many potatoes you put in the fire, because the foil becomes covered with ash, and blends in well with the coals.

Ingredients: large baking potatoes
whole onions, red or yellow

dill, parsley, bacon bits

Directions: Slice potato almost all the way through, but leave enough to hold it together. Slice the onion, and put one slice in between each potato slice. Sprinkle with bacon bits and a little dill. Wrap well with heavy aluminum foil and bury in the coals of the fire. Leave untouched for about 45 minutes, and test for doneness by piercing with a fork - the fork should lift out without lifting the potato. Cooking time depends on size of potatoes and strength of fire. Serve with pat of butter and a few sprigs of parsley.

Green Summer Tip

Skin cancer is the most common cancer in the United States, but it's also the easiest to prevent with the proper protection.

Titanium dioxide and zinc oxide are minerals that physically block ultraviolet (UV) rays from reaching your skin, as opposed to other sunscreens that use chemicals to absorb UV rays. Minerals are considered the best protection against sunburn because they block both UVB rays (which cause sunburns) and UVA rays (which cause skin aging and cancer). Chemical sunscreens, on the other hand, don't always protect against UVA.

SPF is an FDA-regulated rating system that represents how long it will take for exposed skin to burn with the sunscreen applied. For example, if your unprotected skin usually burns in 10 minutes, a sunscreen with an SPF 15 would prevent a sunburn for 15 times that length of time, or 150 minutes. However, SPF only rates UVB rays, not skin damaging UVA rays. For that reason, never rely entirely on a sunscreen's SPF, and look for products that advertise "broad-spectrum protection," which means it protects against both types of rays.

The primary drawback to sunscreens with titanium dioxide or zinc oxide is that they can leave a white tint on your skin. To make the lotions transparent, manufacturers shrink titanium dioxide or zinc oxide particles down to nano-sized particles. Because smaller particles can act differently than larger particles when they enter the body, these nano-sized particles have been cause for concern: Research indicates that nanoparticles of titanium dioxide are small enough to bypass your body's "blood-brain barrier" (a natural defense against foreign substances in the bloodstream) and enter the brain where they can damage brain cells. Larger particles, however, are blocked by that barrier and don't pose this problem. Fortunately, a 2006 Australian government literature review on the topic found that neither titanium dioxide nor zinc oxide penetrate the skin deep enough to actually enter the bloodstream, and most scientific evidence supports the fact that nano-sized particles of these ingredients are often trapped in the outer layer of the skin and not absorbed (they should always be avoided when used in powders that may be inhaled). However, if you'd rather err on the side of safety, opt for sunscreens that use micronized ingredients (particles larger than 100 nm), which are mostly transparent but may still offer a slight tint.

Photography Basics: Understanding Aperture

It's been a while since I did a photography post, so I thought now was as good a time as any! So far in this series I've covered; Photography terms defined, shooting modes, understanding white balance, and window-light portraiture. Today's photography lesson will be a more in-depth discussion about aperture.

The aperture is the hole through which the light passes through to reach the sensor or film. You can actually control the diameter of this hole on your camera. On old style cameras, there is an aperture ring that goes around the outside of the lens. Moving it around changes the diameter of the aperture.

You most likely will not have an aperture ring on your modern lenses, however, your lens still has the diaphragm inside that allows it to open and close, and you’ll have controls on on your camera that will allow you to control that diaphragm.

The numbers are called f-stops, moving up or down a stop halves or doubles the light let into the camera (the reason that the numbers look strange is down to some tricky math). Even though your camera doesn’t have an aperture ring, you’ll find that you can still adjust the aperture of your camera to these same values (although, depending on your lens, you might only be able to go as low as f4 or 5.6)

One thing that is really important to realize about the f numbers is that the smaller the number is, the larger the aperture is. This can be a bit tricky to grasp at first! If you increase the aperture by one stop (thus doubling the amount of light entering the camera), you’ll need to put the shutter speed down by one stop (and thus halving the amount of light entering the camera).