DSLR Lens Selection

NOTE: The contents of this article has been superceeded by the more complete DSLR Lens Buying Guide.

A quick look at available lenses shows that there are far more lenses to chose from than DSLR cameras, yet there is a lot less information about them. Most people know by now that kit lenses only get you so far, if anywhere at all. Here we discuss how to create a personalized set of lens. Remember, those are not the only possibilities, so feel free to adapt those to your needs.

Remember that photographs are taken by a whole camera system, including the photographer. A weak link negatively affects the end-result. A poor camera, a poor lens or poor photography skills all result in disappointing pictures. The most frequent mistake of first-time DSLR buyers is to spend most of their budget on a camera body and then buy the only lens that still fits the budget - or worst, the kit lens. The first rule for choosing lenses is to allocate enough money. As it goes for choosing a digital camera, the two most important things to consider are your subjects and your medium.

Lets start with the practical. How frequently are you willing to change lenses? Are willing to do it in the field? The less you are willing to change lenses on location, the more generic your chosen lens will have to be. This often results in some compromise on image quality or versatility. One who does not want to change lenses, should not get more than one. Having too many lenses results in many of them left behind.

Are weight and size important? Too heavy lenses often end-up left behind too. The second rule is to think of how many lenses are you willing to have. Even without a single heavy lens, choosing too many results in higher total weight in the field. Bulk may be equally important for certain environments. Watch out, based on your needs, you may have to exceed the number of lenses you want to have.

Next comes the needs. Needs vary in terms of angle of view, maximum aperture and other features like stabilization, tilt-shift, magnification and focus distance projection. Angle-of-view requirements translate into different focal lengths due to different sensor sizes. Examples here are quoted for the most common crop factors of 1.5 or 1.6. The equivalent need for full-frame DSLR cameras is noted as a tool-tip.

Think about the widest and narrowest angle desired angle of view. This is a personal choice. Some people always want a wider angle-of-view and some people always want to zoom further. If you already have a DSLR and lens, think about how often you are at the widest setting and wished to go wider because you cannot back up further. How about at the long end, how often do you feel the need to get closer? With a 1.5 crop, wide-angle requires 19 mmRoughly equivalent to 28 mm in 35 mm terms or less. Lenses starting from between 24 and 28 mmEquivalent to between 36 and 42 are mostly satisfactory. Ideally, portrait are taken with an 60 to 80 mm lensFrom 90 to 120 in 35 mm equivalence. Distant subjects and wildlife are easier to photograph with 200+ lenses.

Lenses also vary according to maximum aperture. A wider aperture means less depth-of-fieldConsequently a more blurry background and more light gatheringConsequently faster shutter-speeds. Remember that lenses are generally sharpest 2-stops down from their widest. An F4 lens is normally sharpest around F8, while a F2.8 lens around F5.6. An important feature is optical stabilization. It is an available on some lenses. Digital SLRs with built-in stabilization like the Sony Alpha and most Pentax K-series are advantaged since they obtain stabilization on all lenses at no additional cost. Most importantly, image quality varies tremendously between lenses. More expensive lenses are generally of higher quality than cheaper ones of similar specifications.

A set of one lens can be very light and fast to use since lens changes are not required. On the other hand, single lenses with long-zoom ranges are of limited quality and have narrow maximum apertures. Here are various single lens kits:

Canon

	Stabilized wide-to-medium Canon 17-85 F4-5.6 IS USM
	Stabilized open wide-to-medium Canon 17-55 F2.8 IS USM
	Stabilized normal-to-medium Canon 24-105 F4 IS USM
	Open normal-to-medium Canon 24-70 F2.8 USM
	Stabilized normal-to-medium Canon 28-135 F3.5-5.6 IS USM
	Stabilized wide-to-tele Canon 18-200 F3.5-5.6 IS
	Normal-to-tele Canon 28-200 F3.5-5.6
	Stabilized normal-to-tele Canon 28-300 F3.5-5.6 IS

Pentax

	Wide-to-medium Pentax 16-45 F4
	Wide-to-medium Pentax 17-70 F4 SDM
	Open wide-to-medium Pentax 16-50 F2.8 SDM Weatherproof
	Open normal-to-medium Sigma 24-70 F2.8 Macro
	Wide-to-tele Pentax 18-250 F3.5-6.3

Sony

	Wide-to-medium Sony 16-80mm F3.5-4.5 Carl Zeiss
	Wide-to-telephoto Sony 16-105mm F3.5-5.6
	Open normal-to-medium Sony 24-70mm F2.8
	Normal-to-telephoto Sony 24-105mm F3.5-4.5
	Wide-to-telephoto Sony 18-250mm F3.5-6.3

Nikon

	Stabilized wide-to-medium Nikon 16-85mm F3.5-5.6 VR
	Open wide-to-medium Nikon 17-55 F2.8
	Wide-to-telephoto Nikon 18-135 F3.5-5.6
	Open normal-to-medium Nikon 24-85 F2.8-4
	Stabilized normal-to-telephoto Nikon 24-120mm F3.5-5.6 VR
	Open normal-to-medium Nikon 28-70mm F2.8
	Stabilized wide-to-telephoto Nikon 18-200mm F3.5-5.6 VR

With two lenses instead of one, it is easier to cover a wider-range of focal lengths or to cover a similar range with higher quality optics. Of course, the hassle is carrying both lenses and having to swap them. Swapping lenses in the field can be minimized by matching each lens to a different subject. This reduces the risk of getting dust on the camera sensor.

Several wide lenses exist to complement medium lenses. One can be chosen either to complement a quality medium lens or a regular medium-to-tele lens. A lens ending with a medium focal length can be paired with a telephoto lens for extending your reach without compromising quality at medium focal lengths. Here are some good lens pairs: