Pentax smc DA 50 mm f/1.8
11. Summary
- excellent image quality in the frame centre,
- very good image quality on the edge of the frame,
- perfect correction of chromatic aberration,
- negligible distortion,
- very low astigmatism,
- moderate vignetting,
- great work against bright light,
- functional manual focus ring.
Cons:
- too weak image quality near the maximum relative aperture,
- distinct coma,
- too much plastics in the casing,
- disastrous autofocus,
- high price.
When it comes to optics, the Pentax 1.8/50 is a very solid lens which compares favourably with its competitors. It would be difficult to find a flaw here; if only the lens performed a bit better at the maximum relative aperture and had a better coma correction, we would be completely satisfied. However it’s worth emphasizing that none 1.8/50 lens doesn’t fare well at the maximum relative aperture so the Pentax certainly doesn’t lag behind its rivals. In many categories (chromatic aberration, vignetting, astigmatism, work against bright light or distortion) it actually is the best in its class or at least among the best instruments available.
Please Support UsIf you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free. |
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Three serious problems can be found somewhere else. First – the build quality. A plastic mount seems to be a standard solution in this class as such you can find also in the Canon and the Sony. On the other hand the very well-done Nikkor AF-S 1.8/50 comes with a metal mount. Second – the autofocus. The tested lens deserves to be called a manual lens because the inaccurate, whirring noisily autofocus mechanism is good for nothing. Third – the price. I really don’t know what were the reasons of Pentax when they set it on the level of 1100 PLN. If you add just 300 PLN more you can buy the full frame Pentax 1.4/50 which is faster, with a much better build quality. Apart from that the Nikkor, equipped with an ultrasonic autofocus motor which, contrary to the mechanism you find in the Pentax really works, is also cheaper than the tested lens.
Does the autofocus of the tested lens reflects the quality of the whole series? I really don’t know. Such are the rules of our tests that we deal with an instrument which was sent to us by a shop or a distributor. More general assessment about the quality control can be made only after many tests of products from the same producer. Anyway the conclusions concerning Pentax are not good. If the autofocus works so badly in all 1.8/50 models the situation is very bad. If we got a faulty specimen once again it means we either are extremely unlucky, because it is the next problem Pentax lens, or the quality control in that company is far from perfect…
Sample shots
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/1.8, exp. 1/2500 s, ISO 100 File: JPEG, 4928×3264 pix, 8.87 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/1.8, exp. 1/4000 s, ISO 100 File: JPEG, 4928×3264 pix, 8.22 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/1.8, exp. 1/1000 s, ISO 200 File: JPEG, 4928×3264 pix, 8.07 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/1.8, exp. 1/800 s, ISO 200 File: JPEG, 4928×3264 pix, 7.74 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/1.8, exp. 1/5000 s, ISO 100 File: JPEG, 4928×3264 pix, 7.04 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/1.8, exp. 1/125 s, ISO 400 File: JPEG, 4928×3264 pix, 7.59 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/1.8, exp. 1/8000 s, ISO 100 File: JPEG, 4928×3264 pix, 8.82 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/2.0, exp. 1/1600 s, ISO 100 File: JPEG, 4928×3264 pix, 7.83 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/2.2, exp. 1/50 s, ISO 400 File: JPEG, 4928×3264 pix, 8.51 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/2.2, exp. 1/640 s, ISO 100 File: JPEG, 4928×3264 pix, 7.53 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/2.2, exp. 1/1250 s, ISO 100 File: JPEG, 4928×3264 pix, 7.35 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/2.0, exp. 1/3200 s, ISO 100 File: JPEG, 4928×3264 pix, 8.7 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/2.8, exp. 1/800 s, ISO 200 File: JPEG, 4928×3264 pix, 11.52 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/2.8, exp. 1/5000 s, ISO 100 File: JPEG, 4928×3264 pix, 9.8 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/2.8, exp. 1/4000 s, ISO 100 File: JPEG, 4928×3264 pix, 9.21 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/2.8, exp. 1/320 s, ISO 200 File: JPEG, 4928×3264 pix, 7.98 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/2.8, exp. 1/800 s, ISO 100 File: JPEG, 4928×3264 pix, 9.8 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/3.5, exp. 1/2500 s, ISO 100 File: JPEG, 4928×3264 pix, 9.83 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/4.0, exp. 1/1600 s, ISO 100 File: JPEG, 4928×3264 pix, 7.25 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/4.0, exp. 1/1000 s, ISO 200 File: JPEG, 4928×3264 pix, 9.51 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/4.0, exp. 1/400 s, ISO 100 File: JPEG, 4928×3264 pix, 9.79 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/4.0, exp. 1/800 s, ISO 100 File: JPEG, 4928×3264 pix, 9.61 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/5.6, exp. 1/200 s, ISO 160 File: JPEG, 4928×3264 pix, 8.51 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/5.6, exp. 1/500 s, ISO 200 File: JPEG, 4928×3264 pix, 9.16 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/5.6, exp. 1/320 s, ISO 200 File: JPEG, 4928×3264 pix, 9.54 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/5.6, exp. 1/80 s, ISO 200 File: JPEG, 4928×3264 pix, 9.45 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/5.6, exp. 1/1000 s, ISO 100 File: JPEG, 4928×3264 pix, 9.67 MB |
 |
 |
 |
|
Camera: Pentax K-5 Parameters: 50 mm, f/8.0, exp. 1/800 s, ISO 100 File: JPEG, 4928×3264 pix, 9.72 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/8.0, exp. 1/400 s, ISO 200 File: JPEG, 4928×3264 pix, 9.81 MB |
Camera: Pentax K-5 Parameters: 50 mm, f/8.0, exp. 1/320 s, ISO 100 File: JPEG, 4928×3264 pix, 9.09 MB |
