Although a lot of my macro and closeup photography subjects are irregular in shape, there are those occasions when I have a flat subject (e.g., water lily, leaf). In those instances I want my camera's sensor parallel to the subject. This would usually be performed by stepping away from the camera and observing the camera from both angles, making adjustments, and stepping away again. For the longest time this was my chosen method rather than purchasing an inexpensive bubble. Well, several months ago when purchasing a polarizer filter for my used Nikon 12-24mm lens, Outdoor Photo Gear was giving away LensCoat Double Axis Bubble Levels ($26.95) with purchases over $100.00 if I recall correctly (good polarizer filters aren't cheap). What a great opportunity to finally get a bubble and see if it would really make a difference in my work flow in the field. Why I didn't purchase a bubble sooner is beyond me. These little gems are a fantastic and inexpensive accessory to any photographer's camera bag. It was nice to be able to make all the adjusts I needed in composing this image without have to walk away from my camera. Don't be a bubble head like me, get one and make your experience more enjoyable and efficient. For you landscape photographers, bubble levels are ideal anytime a straight horizon is crucial.