Camera Parts


Written by Gail Bjork

Just because your camera is digital, doesn’t mean the zoom should be. Take a look at the various types of camera lenses to decide which best suits your needs.

There are several types of digital camera lenses and terminology associated with them. The focal lengths of lenses are described in terms of the 35mm equivalent. It’s important to note that just because your camera is digital doesn’t mean your zoom lens should be!

Fixed focal length lens

LensThe camera lens does not change at all. With a fixed focal lens the only way you can get a close up is to move closer to your subject. But don’t get too close ot your subject’s features are likely to become distorted.

Types of zoom Lenses

Optical zoom lens: a true zoom

An optical zoom is a true zoom. Its focal length changes and the zoom mechanism itself extends and retracts so an image is magnified by the lens itself. An optical zoom produces the best quality images.

Digital zoom lens

A digital zoom is not a true zoom. It is a simulated zoom that enlarges the central portion of an image in the camera. The actual length of the lens does not change. Digital zoom produce images with reduced visual quality.

Interchangeable and converter lenses

Single Lens Reflex digital cameras (DSLR) accept a wide range of interchangeable lenses. Some lenses used with a 35mm film SLR may be compatible with the same brand DSLR, though features such as auto-focus may not work if the lens in old.

You can get decent consumer level lenses for reasonable prices, however high quality professional lens can cost $1000 or more.  There are specialized lenses for any photographic scene or subject.

Add-on converter lenses are available for many compact (non-dslr) digital cameras. Converter lens are relatively inexpensive and extend the flexibility and capability of a built-in lens by allowing you to attach another lens.

Related readingRelated reading: extended optical zoom

About the author

Gail Bjork

Gail Bjork, who is passionate about digital photography, is the owner and editor of Digicamhelp.Gail is the author of three illustrated ebooks about digital photography. A number of her photos and digital photography related articles appear at other websites.In 2006, a series of her photos, People in the Louvre, were exhibited at the Underground Photo Gallery
in Iisalmi Finland. Eight of her photos taken in the Florida scrub are on permanent exhibition at Parrish Medical Center in Titusville, Florida.Gail served twelve years as an elected member of The School Board of Palm Beach County, Florida, one of the largest school districts in the U.S. She has also been the editor of a small town newspaper and a free-lance writer. Gail and her husband owned and ran several small businesses.


  • Dar, if you are new to using a DSLR, give yourself some time. You can get sharp images from these lenses but like with most lenses, you may have to add some sharpening when you edit or adjust sharpening in-camera. I own both lenses. You can get an idea what to expect by looking at some of the images I’ve taken with these and other lenses.

    There are so many types of lenses that you should determine which ones will best meet your photographic style. Better lenses will be heavier and more expensive so you may want to rent a few before you buy.

    You may also want to spend some time in my XSi blog. I discuss both lenses and offer some usage tips that you may find helpful. If you have other questions, let us know.

  • I have a Canon EOS Rebel T2i 18.0 OMP DSLR Camera and the two lenses are 18-55 and 55-250. Help! I am not camera literate but I need to know what type of lenses I can get to get a very clear sharp photos as like a professional photograph. The expectations in my photos using the two lenses is not what I expected. I would a much sharper professional image. Please let me know. Thank you.

  • Thank you. This was very helpful as well as your information about the different lens in the previous notes. I checked out the Canon SX30 today so will look at the SX40 and Panasonic FZ150 tomorrow.

  • Janet, a superzoom or compact superzoom would be ideal. They go from wide angle to long telephoto.

    Two popular superzooms are the Canon SX40 and the Panasonic FZ150. They are known as bridge cameras because the have a lot of the sophistication of a DSLR but do not take interchangeable lenses (the also have smaller sensors so don’t do as well as DSLRs in low light, but their low light performance has improved a lot during the years).

    Compact superzooms, also known as travel zooms, don’t have all the bells and whistles of superzooms (and lack viewfinders), but are more compact and have decent zoom ranges. Just about every camera manufacturer makes compact superzooms. Some of the best are made by Casio, Samsung and Sony. Canon and Pansonic make decent compact superzooms too. Check the quality of the LCD before buying; some are more difficult to see in bright light than others (the more dots per inch the higher the resolution of the LCD).

    If you don’t like to fuss with camera settings, get a camera with and Intelligent Auto mode. DO purchase the camera before your trip and take time to familiarize yourself with it!!

  • I have been researching cameras for our family road trip of western national parks. I have no training in photography. I would like to be able to zoom in to my children with mountain backgrounds as well as take wide pictures of the landscapes. I understand optical zoom is best but what range is ideal for these pictures. Thank you.

  • Prime lenses often have superior image quality over most zoom lenses. They are generally less expensive and lighter than zoom lens and have less moving parts…but they are also less versatile. If you could only have one lens, many recommend the 50 1.8mm prime lens as mentioned in this article about the 10 top DSLR accessories.

  • We have information at the site that you will help you gain a better understanding about DSLR lenses. If you decide to buy what is known as a kit lens, which is adequate for many peoples needs, be sure to get the latest model. It should have image stabilization (Vibration reduction).

    DSLR Lens Basics – Discusses some of the features to look for when buying a lens.

    Interchangeable lens quality – Discusses some of the quality differences between lenses.

    DSLR lens types – provides info about the many types of lenses and what they are best suited for photographing.

    Buying a used DSLR lens – Even if you don’t buy a used lens, this article will give you information about Nikon (and other) lens mounts.

    Depending on they type of scenes and subjects you plan to photograph, two zoom lenses may cover all your needs: a wide to mid telephoto lens for scenes and a mid-telephoto to long zoom lens to zoom in close to subjects in the distance (eg; 18-55mm & 55-200mm Zoom Lenses). There are plenty of other lenses, limited only by your pocketbook.

    Have a great trip! You have a fine camera and I’m sure you’ll take plenty of memorable photos.

  • I am looking for buying a telephoto(?) lens  for my Nikon D80 camera to be used during our tour of our National Parks this summer?  Don’t know much about lenses to know what I need-tele/zoom/whatever.  Please help.  Thank you.