New Sigma patent shows design for a 28-70mm f/2 full-frame mirrorless lens

A new patent suggests that Sigma might have a few new exciting lenses on the way soon for mirrorless cameras. The patent describes six lenses, including 28-70mm f/2 and 14-30mm f/4 DG DN lenses for full-frame and 20mm f/1.4, 23mm f/1.4, 28mm f/1.4 and 33mm f/1.4 DC DN lenses for APS-C. While a patent doesn’t always indicate that an item is definitely on the way, all of these focal lengths would fill holes in Sigma’s current mirrorless lens lineup.

With Sigma’s recent expansion into the Fuji X mount APS-C system, releasing a bunch of new APS-C format lenses designed specifically for mirrorless cameras would not only be inside the realm of possibility but it’d be a damn good idea, too. Sigma currently has only four lenses in its DC DN lineup, leaving a lot of room for growth.

There isn’t a massive amount of information over on Asobinet and they didn’t link to the original patent for us to be able to read more, but here’s what was shared:

Overview

• [Release date] 2022-03-02
• [Filing date] 2020-08-17
• [Applicant]
  [Identification number] 000131326
  [Name or name] Sigma Co. , Ltd.
• PROBLEM TO BE SOLVED: To provide an optical system which achieves miniaturization, weight reduction and high speed of focus drive while correcting various aberrations.
• [0002]
  In recent years, with the increase in the number of pixels of digital cameras and the like, it has become necessary to severely correct various aberrations in the optical system used.
• [0003]
  Further, for high-speed and accurate focus drive and wobbling drive for contrast detection during autofocus, it is desired to reduce the weight of the moving portion during focus drive.
• [0004]
  Therefore, in the conventionally proposed optical system, the light beam of the marginal ray is converged by making the refractive power of the group from the object side to the focus group positive, and the configuration of the focus group is also simple. By doing so, a lighter focus group was proposed.

Example 1

• Focal length: 33.72
• F value: 1.46
• Angle of view: 67.78
• Image height: 21.63
• Overall length: 123.95

Example 2

• Focal length: 28.42
• F value: 1.46
• Angle of view: 79.83
• Image height: 21.63
• Overall length: 123.15

Example 5

• Focal length: 20.00
• F value: 1.46
• Angle of view: 74.82
• Image height: 14.20
• Overall length: 94.00

Example 6

• Focal length: 23.00
• F value: 1.46
• Angle of view: 65.76
• Image height: 14.20
• Overall length: 94.00

Example 7

• Focal length: 28.90-67.75
• F value: 2.07
• Angle of view: 76.73-33.8
• Image height: 21.63
• Overall length: 147.85-11.89

Example 8

• Focal length: 14.42-29.10
• F value: 4.00
• Angle of view: 117.62-71.79
• Image height: 21.63
• Overall length: 96.04-74.39

Interestingly, that last one, the 14-30mm f/4 looks very similar to Nikon’s Nikkor Z 14-30mm f/4 S lens in optical makeup, as Asobinet points out. No, they’re not identical – the Sigma one seems to have one fewer lens element than the Nikon – but they are very close.

A 28-70mm f/2 lens for Sony E and Leica L mounts would likely become a very popular lens. At the moment, the only other lens of that range with a constant f/2 aperture is the Canon RF 28-70mm f/2 L USM. Unlike the 14-30mm f/4 above, though, which seems to take inspiration from the Nikon Z mount lens, the optical makeup for Canon’s RF lens does look noticeably different from that of the Sigma patent.

As always, though, the patents may come to nothing. But these lenses are not only viable for Sigma’s mirrorless lens lineup but are also big gaping holes in their current mirrorless lens lineup. So, it would be nice to see at least some of these come to fruition.

[via Asobinet]