Sigma 28-105mm f/2.8 ART: B&H Photo / Amazon / Adorama
Sigma has just had a new patent published (JP 2025-182227) which appears to contain the optical formula for the recently released 28-105mm F2.8 DG DN | Art, along with a few other fascinating sibling lenses that haven’t hit the market—yet.
The patent, published on December 15, 2025, describes a “Variable Magnification Optical System” designed to be compact while maintaining a large aperture (F2.8) and high zoom ratio. While one example matches the specs of the 28-105mm F2.8 almost perfectly, the other examples hint at alternative “standard zoom” concepts Sigma was exploring, including a wider 28-85mm and a portrait-focused 35-150mm.
Here is the breakdown of the optical formulas found in the patent:
This appears to be the optical recipe for the shipping Sigma 28-105mm F2.8 DG DN Art.
This is an interesting “what if” lens. Instead of reaching to 105mm, it trades telephoto reach for a more compact design. In the real world, this would likely be marketed as a 28-85mm F2.8. This would have been a direct competitor to classic standard zooms but with a unique range.
This looks like a direct competitor to the popular Tamron 35-150mm. It provides a highly versatile range for portrait and event photographers who want to avoid changing lenses, all while keeping that constant F2.8 aperture.
Takeaway It is common for manufacturers to patent multiple variations of a lens design during development. It seems Sigma decided the 28-105mm offered the best balance of size and versatility for the market, leaving the 28-85mm and 35-150mm on the drawing board—for now. Would you have preferred a 28-85mm F2.8 or a 35-150mm F2.8 over the 28-105mm? Let us know in the comments.
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