Used at a given distance and aperture, long lenses produce less depth of field than shorter ones. Really long lenses provide minimal depth of field, even when stopped down. And stopping down too far will reduce image quality due to diffraction. So, while bird-in-flight photographers often shoot wide-open, or stopped down a stop or so, from there to get the fastest possible shutter speeds, long-lens landscape photographers usually use intermediate apertures as a good compromise between depth of field and diffraction blurring. Intermediate apertures with a long lens let you focus attention of a sharply-focused plane in the scene, while keeping nearby planes identifiable sharp. Ultimately, the aperture you use is up to your vision—if you need more depth of field, maybe it's worth the loss of definition to diffraction effects when stopping way down, maybe it's not.
While wide-angle lenses are prone to a wide range of aberrations, distortions, vignetting and more, long lenses suffer mainly from chromatic aberrations. So, wide-angle lenses generally need more elements, including some aspherical ones, to correct distortions and non-color aberrations, along with low-dispersion and extra-low dispersion ones to correct chromatic aberrations.
Telephoto lenses generally don't suffer from most of the wide-angle problems and thus, contain fewer elements and no aspherical ones, (except telezooms, which include shorter focal lengths).
All in all, newer telephoto lenses generally produce better results with today's high-megapixel digital cameras than older lenses (which were designed for use with film), and telephotos with low- and extra-low dispersion elements—with such acronyms as extra-low dispersion (ED), extraordinary-low dispersion (ELD), FL, SLD, UD and DO—provide better results than those without.
Image Stabilization: Is It For You?
Nikon 70-300mm ƒ/4.5-5.6G ED IF AF-S VR Zoom
Short answer:Yes, if you shoot handheld. No, if you always use a tripod. Image stabilization in camera bodies and lenses helps you get sharper handheld images, and if you prefer to shoot landscapes handheld, you should opt for it.
Some manufacturers use sensor-shift stabilization in their DSLR bodies (Pentax, Olympus and Sony, for example), while others provide optical stabilization in certain lenses (Canon, Nikon, Sigma, and soon, Tokina).
Canon EF 70-200mm ƒ/2.8L IS II USM
In-body stabilization has the advantage of working with any lens you use on the camera; in-lens stabilization has the advantage of stabilizing the viewfinder image, as well as the recorded one. If you use Live View mode, the live image will be stabilized with either type of stabilization.
It's best to shoot landscapes from a tripod, though, because a tripod can hold the camera steadier than we can (even with stabilization) and will lock your composition in place, so you can carefully examine it and it won't accidentally change as you squeeze off the shot.