What is a kit lens?

If it’s your first time to buy a digital SLR most probably it is bundled with a lens already. It’s called KIT lens. It is an entry level lens that comes with the camera when you purchase it. It’s a kit because it contains everything you need in order for you to start immediately taking photos. It contains the lens, the camera body and most of the time it comes with a free memory card, plus all the basic accessories like battery, strap, manuals and if you are lucky enough another third party strap like Crumpler strap.

For Canon DSLRs, the common kit lens is the 18-55mm lens. When I bought my EOS 40D, it came with the old 18-55mm lens, this model has no IS or Image Stabilizer feature. In the new models like the EOS 550D, you have the option to get the 18-135mm or the 18-55mm. Although I saw in few stores that you also can choose to have the 18-200mm as a kit lens. This model however can be a good walk around lens already. It is under the category of standard zoom lens.

In addition, one professional photographer describes a kit lens as a variable aperture zoom lens – it is so because, the aperture value gets smaller as the lens is zoomed from wide to telephoto. And typically the aperture values are not very fast – f3.5 to f5.6 and fast is like the value of f2.8 or lower i.ed f2.0 and f1.8

As for me, I have sold my kit lens already; replaced it with a not-so-expensive third party lens. A Sigma 18-200mm f3.5-5.6 OS, it is now my walk around lens. I can shoot at 50mm for a portrait style, 18mm wide and at 200mm telephoto.