One of the advantages of being in the CCD fraternity is having the opportunity to look at and review both ranges of vintage lenses and vintage digital cameras that are easily available on the low-end price spectrum of the auction market. Better still is the chance to enjoy the low-noise high-quality images that CCD sensors are acknowledged for. At the same time, cost savings can be factored in if you are moving away from the ever-increasing cost of film for film photography to the CCD format.
I had the chance to do this recently, with a circa 1999 Sigma Asph. IF Zoom 28-105mm 1:3.8~5.6 UC-III with KAF2 lens mount (courtesy of a job-lot buy), fitted to the circa 2008 Pentax K-m (K2000 in the US), which is also a KAF2 lens mount body. The KAF2-mount was Pentax's development sequence for adding auto-focus features to its lenses. The mount allows the lens aperture opening of Pentax A-series lenses to be controlled automatically by the camera when the lens is mounted with the aperture index setting on the lens set to 'A.'
The Sigma Asph. IF Zoom 28-105mm 1:3.8~5.6 UC-III, a total lightweight at 275 grams, is an internal focusing all plastic with a metal mount lens with a 7-blade diaphragm, 13 elements in 12 groups construction with aspherical elements. The lens has a very short focus throw, a closest focusing distance of 50 cm, 62mm filters, and the plastic smooth zoom ring also means you might get some stiffness clunks and nudges as you zoom in and out. On the Pentax K-m the lens is equivalent to 42.8mm - 160.7mm zoom on a 35mm full-frame camera.
The lens is a low-price buy on the auction market, it is not an item on the must-get list, but for what it is worth, the lens enjoys a Sharpness rating of 9.0, Aberrations at 8.8, Bokeh at 7.8, Handling at 9.2, Value at 9.8, and Autofocus at 8.3 on PentaxForums. Acccolades are across the board, ranging from 'a very good Performer, with fantastic IQ for its price,' 'Very good performer lens for such low cost,' to one that broke off its mount while on the way to watch the fireworks.
As I am not a technical boffin on the nuances of qualities of images, color concentrations, aberrations, or such, the images should speak for themselves here:
Initial Initial
My almost standard initial shot when testing lenses currently, a shot from my work table across the room to the ensemble on the dining table, always a nice composition and an indication of the quality of images I will be getting from the lens,
Walking The Zoom
Across the road from outside the door is a small community playground, which I used here to 'walk' the zoom of the lens. Image distances are based on the focal length setting on the lens - at 35, 50, 70, and 105mm. Images were shot in the 'Natural' color setting on the camera, cropped slightly to adjust for tilt adjustment, and tweaked with 'Auto Tone Correction', 'Tone Curve', 'Brightness & Contrast', 'Gamma", and 'Unsharp Mask'.
In The Garden
And, back to my mini garden, a few more shots to really enhance the quality of the lens and its usability both as a normal zoom and as a close-up lens.
Pentax K-m
The Pentax K-m (K2000 in the US), launched in 2008, comes with a 10MP APS-C CCD sensor and is fitted with the Pentax KAF2 lens mount. a follow-up from the KF, KA, and KAF lens mount systems, which was Pentax's development sequence for adding auto-focus features to its lenses. The K-m, a compact entry-level DSLR, shares the same viewfinder and LCD screen with the 10MP CCD sensor K200D and the 14.6 CMOS sensor K20D but has a lighter body and no weather sealing.
No comments:
Post a Comment