Sirui 135mm T2.9 1.8x (Sony E Mount) vs Canon RF 135mm F1.8L IS USM
Sirui 135mm T2.9 1.8x (Sony E Mount) vs Canon RF 135mm F1.8L IS USM
When comparing Canon RF 135mm F1.8L IS USM and Sirui 135mm T2.9 1.8x (Sony E Mount), which one is better?
1. Lens Mount Comparison
The lenses each feature different lens mounts — the Sirui 135mm T2.9 1.8x - (Sony E Mount) features a Sony E while the Canon RF 135mm F1.8L IS USM features a Canon RF — and because of this the preference varies. If you have a compatible camera, then of course that lens will be a better choice for you.
Winner: Tied — It depends on your gear
Regarding lens mount: Popular lens mounts are Canon RF and EF, Micro Four Thirds and Nikon Z. Different lens mounts lets you connect different lenses to camera bodies, but some might not be compatible. This can be helped by using an adapter, like a Canon EF to RF adapter.
2. Largest Aperture Comparison
The Canon RF 135mm F1.8L IS USM has the largest aperture of the two lenses at 1.8 compared to the 2.9 aperture of Sirui 135mm T2.9 1.8x - (Sony E Mount). This means that you get more light to your sensor using Canon RF 135mm F1.8L IS USM wide open, and therefore it might be a better lens in dark situations.
Winner: Canon RF 135mm F1.8L IS USM
Regarding largest aperture: A lower aperture number means that the widest aperture on the lens is larger. This means that more light will hit the sensor and also that the depth of field will be shallower, better separating your subject from the background.
3. Anamorphic Comparison
Winner: Sirui 135mm T2.9 1.8x (Sony E Mount)
Regarding anamorphic: Anamorphic lenses are usually used on cinema cameras and squeezes the image when its recorded, which gives the final, stretched out, image oval bokeh and a different angle of view. The most common lenses, however, are not anamorphic but spherical, which gives a spherical bokeh and is a much cheaper lens design.
Specifications
Full specifications table of Sirui 135mm T2.9 1.8x (Sony E Mount) and Canon RF 135mm F1.8L IS USM:
| Sirui 135mm T2.9 1.8x - (Sony E Mount) | Canon RF 135mm F1.8L IS USM | |
 |  | |
| Brand | Sirui | Canon |
| Weight | Missing | 935 g |
| Lens Mount | Sony E | Canon RF |
| Focal Length | 135 mm | 135 mm |
| Largest Aperture | 2.9 | 1.8 |
| Anamorphic | Yes | No |
| Anamorphic Squeeze Factor | 1.8 | Missing |
| Minimum Focus Distance | Missing | 70 cm |
| Type | Missing | Prime |
| Aperture Range | Missing | 1.8 - 22 |
| Filter Thread Diameter | Missing | 82 |
| Aperture Blades | Missing | 9 |
| Lens Groups | Missing | 12 |
| Lens Elements | Missing | 17 |
| Image Stabilization | Missing | Yes |
| Autofocus | Missing | Evet |
| Macro | Missing | No |
| Weather Seal | Missing | Yes |
| Full Frame Coverage | Missing | Yes |
| Lens Hood Included | Missing | Yes |