14 DAY TRIAL // After the announcement made by Sigma a few days ago regarding the new Sigma 24-105mm f/4 DG OS HSM Art lens, the Nippon manufacturer seems to have a new patent pending for a 300mm f/2.8 OS sports lens.
A new Sigma 400mm f/2.8 OS lens could also be announced later next year, according to Canon Rumors. Some sources state that these two lenses will be in testing at the 2014 Winter Olympic games in Sochi, Russia.
This new patent provides basic information regarding the aforementioned lens, stating a focal length of 289.90mm in a body measuring 189.94mm. Also, the lens construction features 14 pieces in 10 groups including 1 FLD glass and 5 ED glass elements.
The FLD (or “F” Low Dispersion) element is similar in performance and optical characteristics with the fluorite glass, but comes at a more affordable price. With the addition of the 5 ED (Extra -Low Dispersion) glass elements, the probability of getting chromatic aberrations / color fringing in your photos is lower.
Keep in mind that these numbers can only be used as guidelines for the upcoming lens and are subject to change before the final product is released.