Canon RF-S 3.9mm f/3.5 Dual Fisheye
The RF-S 3.9mm f/3.5 Dual Fisheye is a high-performance RF-S standard prime lens engineered for Canon EOS R system mirrorless cameras. Features STM autofocus, and premium optical coatings.
The Canon RF-S 3.9mm f/3.5 Dual Fisheye stands out in the Canon RF lineup as a versatile prime lens. At just 290 g (10 oz), its remarkably compact design makes it an easy addition to any camera bag.
When mounted on a high-resolution R-series body, the image quality simply speaks for itself. The STM motor ensures smooth, quiet focusing adjustments, particularly beneficial during video capture. While lacking L-series weather sealing, its build quality remains robust and practical for everyday shooting. It features Canon's Air Sphere Coating, virtually eliminating flare and ghosting when shooting into backlit golden-hour light. Specialized UD (Ultra-Low Dispersion) glass elements are employed, delivering edge-to-edge contrast and color accuracy.
It strikes a brilliant balance between performance, usability, and value for the modern creator. It pairs perfectly with a 70-200mm to complete your kit.
✅ Strengths
- Ultra-compact and lightweight design (290 g (10 oz))
- Customizable Control Ring for aperture, ISO, or exposure compensation
⚠️ Considerations
- No professional weather-sealing gaskets (use caution in rain or dust)
- No in-lens optical stabilization (relies on camera body IBIS only)
- Stepping motor (STM) autofocus may be slower than USM for fast-action tracking
Full Technical Specifications
| Lens Model | Canon RF-S 3.9mm f/3.5 Dual Fisheye |
| Lens Mount | Canon RF |
| Sensor Format | APS-C |
| Optical Construction | 8 elements in 6 groups per optical path |
| Special Glass & Optics | 2 UD elements per lens, Air Sphere Coating |
| Min. Focus Distance | 0.20 m (7.9 in) |
| Max. Magnification | 0.03x |
| Image Stabilization | Electronic VR stabilization |
| Diaphragm Blades | 7 |
| Autofocus Motor | STM |
| Filter Diameter | Rear Gelatin Holder |
| Dimensions (D × L) | 112 mm (4.4 in) × 53.5 mm (2.11 in) |
| Weight | 290 g (10 oz) |
| Lens Hood | Built-in / None |
| Release Date | 2024-06-11 |
| Series Classification | Standard |
| Estimated MSRP | $1,099 |
Features & Optical Technology
Recommended Photography Genres
Frequently Asked Questions
Q: Is the RF-S 3.9mm f/3.5 Dual Fisheye weather sealed?
A: No, this lens does not feature professional weather sealing. It is recommended to use caution or a rain cover when shooting in wet or dusty conditions.
Q: What size filter does the RF-S 3.9mm f/3.5 Dual Fisheye use?
A: The lens features a Rear Gelatin Holder front filter thread. Any circular filters (like UV, CPL, or ND) will need to match this Rear Gelatin Holder diameter.
Q: Can I use this RF-S lens on a full-frame Canon EOS R camera?
A: Yes, you can mount RF-S lenses on full-frame RF cameras. The camera will automatically enter a 1.6x crop mode, capturing a cropped image with a field of view equivalent to 6mm.
✓ Includes configurable electronic Control Ring for aperture, ISO, or shutter speed.