No, Sigma Did Not Make Canon’s New 10-20mm f/4 L IS STM Lens

Canon 10-20mm f/4 L

Late last night, Canon introduced a new wide-angle zoom lens — the 10-20mm f/4 L IS STM — that is unlike any optic it has ever produced. It’s unique, and one publication published a story with quite an incendiary accusation: Canon didn’t actually make it, Sigma did.

The author makes this accusation based on one line in EXIF data found on one of the sample photos Canon provided to media ahead of the public announcement of the lens. That data appears to show that the lens is not the 10-20mm f/4 L IS STM but instead the Sigma 10-20mm f/4-5.6.

From this, the article says only one of two things could have taken place: either Sigma made the lens or the photographer made a mistake and used distortion correction from an older Sigma lens. The author basically immediately dismisses this second explanation, saying that it would be an odd choice because the Sigma lens is designed for APS-C while the new Canon lens is made for full-frame.

Canon RF 10-20mm f/4 L IS USM

“I’d like to believe either answer. Canon is bound to say that it was a mistake because that’s just how Japanese companies are. They tend to bash each other in meetings, but in reality, they’re all using the same components. In truth, probably no camera companies could be completely self-sufficient except for Canon, Sony, and Panasonic. If this were a decade ago, Samsung could also have been added to that list,” the author writes.

Canon RF 10-20mm f/4 L IS USM

The inflammatory nature of these words aside, the author is ignoring one other possibility: it happened by accident and without the photographer even noticing.

As mentioned, Sigma has a 10-20mm f/4-5.6 lens for APS-C DSLR cameras and, if someone popped an image into an image editor that did not include support for the new Canon lens — which, at the time the lens was announced would be all of them — the software could just automatically try to fill in EXIF metadata based on the EXIF data that is recognized — like focal length.

Canon RF 10-20mm f/4 L IS USM

Members of PetaPixel‘s staff have shot with lenses without rich metadata — either pre-release lenses or those from lesser-known third-party manufacturers — and it has seen software just make guesses. This is not unusual.

Looking closely at the metadata across the photos that Canon provided, some do show the exact serial number and lens model as the 10-20mm f/4 L IS USM while others are far more vague. In one case, we see the optic described as “Canon RF 50mm F1.2L USM or other Canon RF Lens,” which backs up the previous statement of about there being limited metadata with prototype lenses.

In order to get enough photos to publish with the announcement, Canon likely sent a few of these lenses of varying age and state of firmware to a small group of photographers. Some of those lenses had the ability to show the right metadata, others did not. This is not unusual.

As if all of this information wasn’t enough to dismiss the outlandish assertion, Canon is also able to clear the air.

“Canon confirms the RF10-20mm F4 L IS lens is a Canon-designed and manufactured lens,” the company tells PetaPixel in an email.

So, no. Sigma did not design or manufacture Canon’s 10-20mm f/4 L IS STM.

Image credits: Canon