Modern 50mm Shootout: Pentax D FA* 50mm, Samyang 50mm, Pentax DA* 55mm F1.4
Bokeh
Bokeh is a Japanese term which refers to the quality, look and texture of the background blur. It does not relate to the depth of field but to the areas in the image that are beyond the range that is expected to be in focus.
A smoother bokeh is generally perceived as being of a higher quality. Bokeh is influenced by the lens design, with a significant role being played by the aperture. Its shape will influence the look of the bokeh, especially around highlights and light sources.
Modern lenses generally produce pleasing bokeh since this element is often sought after by buyers. The three tested lenses' fast, F1.4 maximum aperture should help with the out of focus rendering, as should their rounded aperture blades.
Bokeh Test
In order to evaluate the characteristics of the background blur, we took pictures at varying apertures, using these test parameters:
|
|
Results are directly transferable to APS-C cameras.
| DA* 55mm | Rokinon 50mm | D FA* 50mm | |
| F1.4 |  |  |  |
| F2 |  |  |  |
| F2.8 |  |  |  |
| F4 |  |  |  |
| F5.6 |  |  |  |
| F8 |  |  |  |
| F11 |  |  |  |
| F16 |  |  |  |
| F22 |  |  |
At the widest, F1.4 aperture, there is little to differentiate the three lenses. The D FA*'s blur seems creamier, particularly at the bottom right. For all three lenses, highlights are well formed and no harsh patterns are visible. The differences between the three lenses are subtle at best.
Even when the aperture closes, highlights preserve their round shape and the out-of-focus texture remains creamy for the three lenses. All three produce superb bokeh.
More examples can be found in our Samples Gallery.
Verdict
The three lenses under test produce pleasing bokeh, with creamy textures devoid of harsh shapes, and well-formed highlights. The D FA* has a small advantage over the other two lenses at the widest aperture values.
