The featured image you see in this post was shot with a lens fashioned some 40 years ago: a Super Takumar 50mm f1.8. Composed and shot in low light (dusk) and with a very shallow depth of field, the image is good starting point for a conversation on superior glass (glass, for the neophyte, is photographer shorthand for lenses).
If you’ve picked up an entry-level digital SLR camera, you may have opted for one of the “kit” lens that come as a package with the body. These starter lenses are serviceable tech for the beginner or someone whose intent is simply to get good images for personal use. If you’re just looking to document your family events, a kit lens is probably all you’ll ever need. Heck, as many of you who have been following my blog for awhile know, I’ve managed to get some impressive shots with my T3i and its 18-55mm kit lens. With auto-focus when you need a shot in a jiffy, and image stabilization to boot, it’s not a bad lens by any means. It’s also quite affordable if you’re on a budget.
These are the pros of a kit lens in general. The cons include the quality of the material – plastic housing and cheaper optics – and the relative slowness of these lenses. A “fast” lens comes with a larger maximum aperture, represented by a smaller f-stop number like 2.8, 1.8, or 1.4. (Don’t let the wording fool you. Though we use the word “fast,” the term has nothing to do with the camera’s speed.) The larger aperture allows you a great deal of latitude with your depth of field (see example image below) and better image results in lower light settings.
Many faster lenses with high quality glass offer brilliant bokeh as well. Bokeh is derived from a Japanese word describing how a lens renders out-of-focus points of light. How the background and particularly highlights in the background are rendered can make a tremendous difference in the aesthetic of your image. With the right bokeh, a fast lens and a shallow depth of field can produce ethereal, impressionistic photos.
The Canon 18-55 kit lens has a maximum aperture of f3.6 – 5.6, The f-stop varies because it’s a zoom lens, so f3.6 is available to you only if the lens at a focal length of 18mm. If you’re zoomed in at the maximum focal length of 55mm, your maximum aperture is f5.6. In full sunlight or with a flash, you can shoot at ISO100, 200, or 400 and get sharp, vibrant images with these smaller apertures.
But suppose you’d to photograph something and have it stand very starkly against a background, or capture something in lower light. You’re going need a faster lens, and that’s why I strong recommend that you replace your kits lenses, or at the very least augment your collection with a few lenses of higher quality.
Peruse the Canon website and you’ll very quickly see that superior lenses are going to cost you some serious ducats. If you can afford the modern glass with IS (Image Stabilization) and auto-focus (for those who want it), go for it. Most of us, however, are on a pretty lean budget and $1999 for a lovely EF 24-70 f2.8 is a bit much.
The good news is that if you’re willing to sacrifice auto-focus and image stabilization, you can get some incredibly good glass for a pittance. I’m talking about Zeiss-manufactured optics from reputable brands like Pentax and Vivitar. The lenses are very old, but almost unbeatable in terms of quality. You’ll notice significant improvements in your images, though you’ll still see some limitations with your camera body. (A noisy sensor, for example, won’t be fixed with a better lens).
All you’ll need is an adaptor that fits the Canon mount and the screw lens. For decades, the popular 35mm camera mount was the M42 x 1mm standard, and there are many M42 adaptors available for Canon and other brand cameras. You can pick up adaptors that provide metering information and focus confirmation, too, so even without auto-focus you’re not limited to purely your own instincts about how in focus you are.
The adaptors are roughly $10 apiece, and M42 lenses can run anywhere from $20 – $300 depending on a number of factors. The Super Takumar 50mm prime lens I used for the first image was about $23 – a great bargain for superior glass. When shopping online for used M42 lenses, pay attention to the seller’s descriptions. Common problems with these older lenses include fungus on the glass (which can be cleaned) and oil in the blades. A small amount of dust inside the lens is generally inevitable, but won’t impact your images significantly.
I recommend prime (i.e., fixed focal length) lenses to begin with. A 50mm prime is a nice start, and a rounded glass collection should have a 135 or 200mm for portraits and, if you’re shooting landscapes, a 28mm or less.