| sigma nomenclature
lets be pragmatic about it. in the film era all sigma lenses were full frame, they had to be. the top of the line was the EX series.
when DSLRs first came out, you still bought a film lens because the "digital coatings" were still some time off. so when i bought the Sigma 70-200/2,8 EX and the Sigma 1.4x EX teleconverter this is how the optics were marked.
about 2 years later sigma came out with not only DC lenses for cropped sensors, but also DG lenses, which were full frame lenses with digital coatings. many of their first series were simply the same film lenses with digital coatings.
so what are digital coatings, specially they include coated rear elements to prevent reflections and clouding (reduced contrast) from incident light bouncing off the filter in front of the sensor, which is much more reflective than the emulsion side of film. non digital lenses sometimes have very low contrast when shot on a DSLR or a hazy low contrast donut in the middle of the frame
with the sigma 70-200/2.8 EX (non DG) or with the 1.4 x teleconverter i have never had an issue indicating that sensor reflection was systemic issue with either the lens or the TC
if you are going to purchase a TC today, there is no option for a new TC, you only get the digital one because the standard one went out of production about 14 years ago, but it wont make any noticeable difference in my opinion
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Post #12 by Wild Mark
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