This Soligor 2x converter is similar of the earlier version of Kenko converter. I use this converter mainly with my canon 200f2.8L usm lens. I tried on a canon 50/1.8 as well, the results unlike with the Kenko 1.4 dgx are very bad. Usually the converters works best with prime telephoto lenses. The 2x teleconverters autofocuses normally only with f2.8 lenses on consumer or prosumer bodies. I used this converter mainly for birding and wildlife photos. I had a Soligor 100-400 lens before and use this converter with that lens as well, with not so good quality results, but the magnification was very interesting, I can make pictures of Great Egrets which I haven’t seen with my eyes. This 2X converter doubles the focal length of the lens, while steals 2 stops of light. This means the 200mm lens going to be 400mm, the 300 mm lens going to be 600mm, and so on. The f2.8 lens becoming f5.6 lens, the f5.6 lens going to be f11 lens. Wide open this converter makes soft images, this means that resulution is good, but contrast is quite reduced. With my canon 200/2.8L I need to stop down the lens to f4.5 to have the best results.(f9 with the converter). This converter doesn’t report to the Camera body so in Exif data the real focal length and aperture doesn’t appear.
Build quality: Built quality of this converter is quite ok, no wobbling, stable but not so built like the tank as the canons. The converter is much smaller and lighter than the canon 2x MkII.
Autofocus operation: With the canon 200L autofocus operation is quite quick, with good precision. In fact it is much quicker and perhaps more precise, and not so hesitant than the canon.
Optical qualities: With a good lens can produce acceptable results. See galleries below. With an average lens more of a fan to play with the long focal length.
Compare to Canon 2X converter: The canon is better wide open, and canon colours and sharpness are better. The canon is much more expensive. The canon cannot attach to normal lenses, because of the protruding front element, see below. The Soligor can attack almost to any lens without problem.(better check perhaps exotic lenses if the lens has rear parts). The Soligor is overexpose 2/3 compare to the canon. (It came out when I made a comparison shots.)
Stack with 1.4 converter: In good light I like to stack this converter with a Kenko 1.4 dgx converter, resulting an 560mm f8 autofocusing combination. This combination is a fun to use in good light, because of the added reach, see pictures below. With this combination some post processing needed to make acceptable results. (Added contrast, perhaps sharpening.) This combination tend to overexpose with 2/3 stops as the converter itself, so I set up exposure -2/3 stops. The main difference this combination is the reduced contrast, and sharpness compare to the 1 converter combination, but in good light possible make surprising results.(see my review about teleconverters).
My pictures with the 200f2.8L and the Soligor converter below :