Pentax-DA 18-55mm F3.5-5.6 WR Review

Flare

Lens flare is an effect caused by stray light reflecting internally on the various optical elements of a lens. The result in the image can be an overall decrease in contrast (veiling flare) or the presence of unwanted artifacts in the composition (ghosting). 

Lens manufacturers use various strategies to reduce the lens flare. In the case of the lens at hand, it includes the SMC (Super Multi Coating) feature and a lens hood. The removable lens hood helps to prevent light from getting into the front element at angles outside of the field of view, while the SMC coating is an antireflective coating that attempts to reduce internal reflections within the lens' structures. While these two measures can help immensely, the effects of lens flare can only be minimized and not entirely eliminated.

For the test, we will try to intentionally induce lens flare by taking images with the sun just outside of the field of view (in this case, the upper left of the frame). We perform this test with and without the lens hood installed. Click on the image for a larger version.

At 18mm, with lens hood	At 18mm, without lens hood
At 55mm, with lens hood.	At 55mm, without lens hood.

Verdict

In both ends of the zoom, there are very little veiling flare and ghosting, even without the lens hood. With the lens hood installed, there is observable reduction in the veiling flare (upper left corner) in the 18mm image, but there is no difference in the 55mm image. This is because the lens hood has to designed for the widest focal length of the lens, otherwise it would obstruct the field of view.

We conclude that the DA 18-55mm WR is very resistant to flare. Although flare is not completely absent, it is only present in negligible amounts thanks to the lens design and SMC coating.