HD Pentax-DA Fish-eye 10-17mm F3.5-4.5

General Image Quality

On the following pages we will look in detail at every measurable performance parameter, but for the moment we will consider some subjective elements that can make or break an image.

Field of View

A fisheye’s field of view is what makes it interesting in the first place. In the case of the HD DA 10-17mm, on APS-C at 10mm, the diagonal field of view is a whopping 180°. This means that the lens can image objects which are almost completely to the side of the camera.

At 17mm, the lens still offers a wide field of view of 100° on the diagonal, a pretty large value.

The extreme field of view, coupled with the uncorrected distortion, means the images produced by this lens will have a unique look, which can be pleasing when used with care, but can also yield strange results, as shown on the image below.

Care should be applied when composing. For instance, on the two images below the only difference is the tilt of the camera. A straight line near an edge of the frame will be strongly curved.

However, putting the horizon near the center is not always advisable. As shown below, sometimes it is better to accept some curvature of the horizon to avoid distorting other objects in the frame (see the wires to the top right).

Thanks to its close focusing capabilities, the HD DA 10-17mm is a surprisingly versatile lens. It can also be quite sharp.

On a full frame camera, this new version of the 10-17mm design offers a new capability. By removing the lens hood, one can create almost circular images, creating interesting and innovative results.

Color and Contrast

The HD DA 10-17mm lives up to expectations and produces typical Pentax results, with rich colors and beautiful brightness gradations. Click on the image below for a full size crop of the leaf, showing the colors and detail.

Metering and Exposure

The lens' metering performs correctly, for the most part. However, the enormous field of view means that it is easy to include bright light sources in the frame. In our experience with the K-3, we observed that there was a tendency to underexpose slightly.

Starbursts

Starbursts with the HD DA 10-17mm are better than expected, without breaking new ground. At wider apertures there is nothing to see, but at F8 well-defined starbursts are visible. They tend to flare outwards, making them less defined, but can still contribute to the general quality of an image.

F4.5
F8

Lens Corrections and EXIF Data

The HD DA 10-17mm includes all the necessary data for modern camera bodies to apply in-camera lens corrections when required. Vignetting, diffraction, aberration, and distortion can be adjusted in-camera. Of course, distortion cannot be fully corrected.

EXIF data are complete and accurate, and Pentax camera bodies are able to record every relevant parameter into the file. Note that it is up to your software to properly decode these data when an image is viewed on a PC.

On-Board Flash Usage

When testing on a K-3 (an APS-C DSLR), the wide field of view means that there is a shadow despite the small size of the lens. At 17mm the flash casts a regular shadow, but at 10mm it cannot illuminate the whole field of view of the lens.

10mm
17mm

User Report

Using any fisheye lens comes with a learning curve. One cannot simply mount a fisheye and shoot blindly. Thankfully, the learning curve is short and users are quickly able to use the lens’ capabilities creatively. Also, thanks to the less-distorted 17mm focal length, the HD DA 10-17mm can produce images closer to what a photographer is used to seeing.

When using a fisheye, one must pay close attention to straight lines and composition. A fisheye cannot be used in all situations. When used properly, it is an additional tool in the photographer’s bag.

In the next sections we will look at the optical performances of the HD DA 10-17mm.