16. Lenses In Abundance

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Our two competitors are available in kit form with very similar lenses -18-55mm zooms with the same apertures: f/3.5 at the wide end, which is quite good, and f/5.6 at telephoto, which is less attractive (but common with this type of lens). The range of equivalent focal lengths is 27-82.5 mm, which covers just about all normal needs, even if some may find the range a little short on the telephoto end.

Obviously the construction of these optics is fairly simplistic, with an obvious "light plastic" feel. We give Pentax the clear advantage, since its little zoom has both a distance scale (absent on the Nikon) and a front element that does not rotate when focusing. The importance of this last point becomes clear when you use a filter such as a polarizer that needs to be used in a specific orientation.

For practical performance, on the other hand, we give the nod to Nikon, since the photos it produced had better definition and more homogeneous resolution (except at wide apertures, when the edges and corners showed perceptible loss.) With the Pentax, quality loss was always somewhat visible, even when stopped down. Obviously this will be detectable most of all on large prints. For normal prints (up to 8x10"), it won't be a problem.

Both lenses were capable of very close focusing - around 9.8" (25 cm) from the plane of the sensor, or about 3.9" (10 cm ) from the front lens - for so-called "macro" shots of flowers, insects and other small objects. The minimum field of coverage at the maximum focal length of 55 mm is approximately 2.6" x 1.7" (6.5 x 4.4 cm) for the Nikon and 2.8" x 1.9" (7 x 4.7 cm) for the Pentax. Those are very comparable capabilities and they correspond nicely to amateurs' needs.

The Nikon D50's 18-55 zoom is undoubtedly not ideal for photographing butterflies, but it's entirely possible! 55 mm, aperture priority, 1/100s f/11, ISO 800

Pentax istDL, aperture priority, ISO 200, 18-55 at 55 mm, 1/125 s f/8

Naturally these inexpensive lenses are limited, especially because they are rather slow - they have small maximum apertures, which means it is hard to use fast shutter speeds. You can choose to fit these bodies with brighter lenses, but then the total bill can sometimes rise quickly. You could also go for a wider range of focal lengths; our favorite for that would be the Sigma 3.5-6.3/18-200, which covers focal-length equivalents of 27-300 mm at a very reasonable price and with very good overall quality.