Besides the sensor, the most important part of a digital camera is a lens. A lens admits light and focuses it onto the sensor. Lenses vary in price, quality and in range. A wide-angle lens allows you to view a wider range than normal. It is useful when you are in a confined space such as indoors or similarly constrained. A telephoto lens allows you to view far away objects as if they were closer. They magnify your distance view. A normal lens takes an image as you see it with your eyes, neither closer nor wider.
Lenses range in price and quality based on their optics. Higher quality lenses use higher quality glass with less distortion or defects and provide better and sharper pictures. Lenses can range anywhere from $100 to $10,000 or more.
Your cell phone and many basic cameras come with lenses that are fixed and cannot be changed. They may have a zoom capability which may include the ability to adjust the lens from a wide angle through normal to telephoto. Cell phones and point and shoot cameras generally have this zoom capability but they just have the one fixed lens. Generally digital DSLR cameras have interchangeable lenses. You can remove one lens and replace it with another. You can have a wide angle lens but then want to shoot telephoto shots and you replace it with a telephoto lens. This allows for higher quality pictures.
Generally interchangeable lenses come with a focal length measurement. In general a normal lens is 35 mm on a full frame DSLR. Wide angle lenses are lower such as 18mm. Higher numbers such as 200mm are higher telephoto capability.
The first photo series above shows the same picture with the same camera and different focal length lenses. The lower numbers show more of the scene and are wider. The higher numbers show less of the scene but are closer. The second graphic illustrates the wide or narrow aspect of different focal length lenses
Another type of lens is a macro lens (called a micro in Nikon). This is a special lens that allows you to focus really closely so that you can take pictures of small things such as insects, flowers, or tiny details.
Please read these excellent sources for information on lenses.
Your assignment will be to go on a photo shoot and try to take photos that illustrate at least normal and zoom or telephoto shots of the same image. If you have the lenses or capabilities please consider wide angle or macro as well. Please post two photos from this shoot and post comments on your photo including where it was taken and whether it was normal telephoto wide or macro. Also post a comment on someone else’s photo. All plagiarism rules still apply.