Targets for objective Pentax and Samsung
Pentax has abandoned the 24×36 format and has no immediate plans to return there. Accordingly, most of its objectives are limited to small sensors. The arrival of the SDM ultrasonic motors introduced a break compatibility resulting in loss of the Autofocus certain objectives, using the bayonet KAF3 “with the devices prior to K10D, K100D Super and GX-10; goals Sigma HSM suffer the same inconsistency. Other SDM using the bayonet KAF2 “remain compatible with earlier devices.
Wide Angle
Sigma 10-20 mm f/4-5, 6 EX DC
Unlike the Nikon earlier in these pages, the Pentax version of the wide-angle Sigma does not have the HSM engine. The development uses the engine of the camera, more noisy here but not slower. For the rest, the objectives are identical and found the results overall as correct.
Price: 500-650 Euros
Macro
Sigma 70mm f/2.8 EX DG
Surprisingly, the conclusion that our English colleagues came to regard this goal. Once the full opening, the sharpness is excellent on the whole image is higher than that obtained in many of the “official” yet much more expensive. A real success, which would become an easy winner if all mounts had an ultrasonic motors: the Canon and Nikkor equivalents were preferred for their practical aspects, not just their equivalent.
Price : 370 – 470 Euros
Universal
Tamron AF 18-250 mm f / 3,5-6,3 Di II LD Aspherical Macro
Specialist extreme zoom, Tamron past few years has already embarked on a course: 18-200, and 18-250 mm, and very recently a 18-270 mm which is lacking at the moment tests seriously. Let us therefore this modest 14x zoom, covering a field of 27 to 375 mm 24×36! Such a magnitude is not without side effects: the optical quality is the withdrawal of more sober zoom and telephoto lens opening (f / 6.3) may limit the performance of the auto. However, the practical side can prevail and for common use, this offers a very acceptable quality. Note the slightly later abuse the term “macro” (the peak 1:3,5) and the existence of a Pentax, a little more expensive, this goal.
Price : 430 – 490 Euros
Tele
Tamron AF 70-300 mm f/4-5, 6 Di LD Macro 1:2
In the absence of a very good target to 500 euros, we will correct a target to 200 euros. This is the case with this Tamron, who suffers from a bit of weakness beyond 200 mm (it will close the aperture at f / 8), but dominates the Pentax FA J 75-300 mm never adapted to digital and, more surprisingly, the competition Pentax DA 50-200 mm yet designed for APN. Note the excellent performance Close: develop 95 cm in depth zoom, this lens allows photography full part a matter of 5 cm
Price : 140 – 180 Euros
Note
We have noticed the absence of Pentax objectives of this selection. In fact, Pentax has not developed internal targets public and macros 50 mm and 100 mm are goals silver quickly adapted. In the range considered here, the manufacturer proposes objectives often from other manufacturers (Tamron, Tokina …) are not better than the originals. The Pentax range really is a bit more sophisticated, with the objectives to SDM engine and, for those who are not afraid to move to frame an excellent range of optical fixed focal.
