The debut of the Canon RF 15-35mm f2.8L represents a pivotal moment for the EOS R mount, serving as its inaugural ultra-wide lens and a cornerstone within the system. Boasting the hallmark performance expected from premium RF lenses, it excels in capturing subjects at various distances, whether for photography or videography. Its primary competitor, the Canon 16-35mm f2.8L Mark III, is a formidable contender. Physically akin to its EF predecessor, the RF version maintains a compact form factor and comparable weight. Through rigorous testing, the RF lens consistently demonstrates results akin to its predecessor, with minor distinctions such as a slightly wider zoom range at shorter focal lengths and the inclusion of optical stabilization. While modest in its effectiveness, this feature enables sharper handheld shots at slower shutter speeds, particularly advantageous for both photography and videography. Despite a marginal increase in price over the EF variant, the RF model offers significant value, boasting wider coverage, a customizable control ring, and smoother, quieter autofocus performance. For EOS R users seeking an ultra-wide f2.8 zoom lens, the Canon RF 15-35mm f2.8L emerges as a highly recommended choice, blending optical excellence with innovative features tailored to modern imaging needs.