Canon RF100- vs SIRUI
Updated July 2026 — full head-to-head comparison.
Overview of the Canon RF100-500mm and SIRUI 20mm T1.8 Anamorphic Lens
The Canon RF100-500mm F4.5-7.1 L IS USM Lens is a super-telephoto zoom lens priced at $2,898.95, designed for the EOS R series mirrorless cameras. In contrast, the SIRUI 20mm T1.8 1.33X Anamorphic Lens is a compact autofocus lens available for $599.00, targeting video creators with its cinematic capabilities. The key difference in their purpose is evident: one is tailored for long-range photography, while the other excels in video production with a wide-angle perspective.
Design and Build Quality
The Canon RF100-500mm lens features a robust L-series construction that ensures durability and resistance to dust and moisture, making it suitable for challenging conditions. The lens incorporates advanced optical technology, including one Super UD and six UD lenses, ensuring high image quality. On the other hand, the SIRUI 20mm lens is notably compact and lightweight, weighing only 1.06 lbs, which makes it perfect for handheld and run-and-gun shooting scenarios. The choice between these lenses will largely depend on whether you prioritize ruggedness and versatility or portability and ease of use in your shooting environment.
Optical Performance
The Canon RF100-500mm boasts a versatile zoom range of 100mm to 500mm, which is ideal for capturing distant subjects in sports, wildlife, and aviation photography. Its optical image stabilization system allows for up to 5 stops of shake correction, enhancing clarity in images taken at long focal lengths. In contrast, the SIRUI 20mm T1.8 lens offers a 1.33X squeeze factor that allows for immersive cinematic visuals with a 2.35:1 widescreen ratio, ideal for filmmakers looking to achieve a unique aesthetic. Both lenses deliver impressive optical performance, but their applications cater to different creative needs—photography versus videography.
Autofocus Capabilities
The Canon lens features high-speed Dual Nano USM autofocus motors, ensuring smooth and quiet focusing, which is critical for capturing fast-moving subjects. This lens excels in dynamic environments where rapid autofocus is necessary. Meanwhile, the SIRUI 20mm T1.8 lens is equipped with a precision STM stepping motor that allows for both manual and autofocus capabilities, with added eye-tracking features. The autofocus switch provides filmmakers with greater control over their shooting process. Thus, while both lenses offer strong autofocus systems, the Canon lens may be more suited for photography, while the SIRUI lens caters to videographers seeking flexibility.
Price Comparison
The Canon RF100-500mm is priced at $2,898.95, making it a significant investment for serious photographers or professionals. In comparison, the SIRUI 20mm T1.8 lens is priced at $599.00, which is about 79% cheaper than the Canon lens. This price difference highlights the disparity in their target markets, with the Canon lens aimed at professionals requiring high-end telephoto capabilities, while the SIRUI lens is targeted at budget-conscious filmmakers looking for quality in the anamorphic category.
Versatility in Use
The Canon RF100-500mm lens is designed for a range of applications, particularly in sports and wildlife photography, where its long focal length becomes a crucial asset. Its minimum focusing distance of 3.0 feet allows versatility in composition, even at significant distances. Conversely, the SIRUI 20mm lens shines in scenarios requiring wide-angle perspectives, such as landscape photography and indoor shooting. Its T1.8 ultra-fast aperture allows for effective low-light performance, which is beneficial for night scenes or events with limited lighting. When considering versatility, the choice depends on whether the user needs telephoto capabilities or wide-angle flexibility.
Target Audience
The Canon RF100-500mm lens primarily targets professional photographers and enthusiasts who demand high-quality images in challenging environments. Its features cater to those invested in wildlife and sports photography. In contrast, the SIRUI 20mm T1.8 lens is tailored for filmmakers and content creators who require a compact, lightweight solution for dynamic shooting scenarios. It serves those who prioritize cinematic visuals and creative control in their video projects. Therefore, each lens appeals to distinctly different user bases based on their respective creative pursuits.
Which should you buy?
Choosing between the Canon RF100-500mm F4.5-7.1 L IS USM Lens and the SIRUI 20mm T1.8 1.33X Anamorphic Lens comes down to your specific needs as a photographer or videographer. If you're focused on capturing distant subjects with exceptional quality, the Canon lens is the clear choice. However, if your work leans toward filmmaking and you desire a versatile, wide-angle lens that maintains quality in low-light conditions, the SIRUI lens is the better option. Ultimately, your decision should align with your primary photographic or videographic goals, budget, and the types of situations you often find yourself shooting in.

