Larger Than Life Sunsets
So, how do you get those sunset shots where the really is big sun? Simple: use a longer lens (you knew that already I bet). A standard 35mm film frame measures 24x36 mm. As a general rule, for each 100mm of focal length, the sun will appear 1mm larger. In other words, with a 400mm lens, the sun will be roughly 4mm in the frame, or one sixth of the width of the frame. As you can see, this could be an opportunity to get out your teleconverter. Since there are no sharp edges to the sun though, you can still get usable sunset images with combinations that wouldn't be sharp enough for other subjects.
Now that you've stacked every teleconverter you own together, there're couple more important points you should keep in mind before trying to get that shot. First, the sun is very bright. Never look directly at the sun, especially when magnified through a long lens; it could do permanent damage to your eyes. You can aim your camera by looking at its shadow; it is facing the sun at the point where the shadow of the lens is smallest.
The second point is that the sun is very hot. If left pointed at the sun, the heat buildup inside your lens can actually melt the glue used to assemble it and warp critical components. Keep the lens cap on between shots while waiting for things to develop.
One thing I've tried that does help with both the heat and the brightness is the use of a piece of number 14 welder's glass as a filter to aid in composition. You can pick one up at a large, well-stocked hardware store for just a few bucks, and it's one of the only easily available ways to safely look at the sun. First, set your exposure as in last week's tip (the sun will not be in the frame so you can do this safely without the filter). Then, hold the welder's glass over the end of the lens to protect the lens itself as well as your eyes while you recompose. The sun will appear a sickly green shade, but it's safe to look at. When you're ready to take the shot, remove the welder's glass and fire away. Just remember to put the lens cap back on or point the camera away from the sun when done.