Sony FE 400 mm f2,8 GM OSS vs Sirui 135mm T2.9 1.8x (Sony E Mount)
Sony FE 400 mm f2,8 GM OSS vs Sirui 135mm T2.9 1.8x (Sony E Mount)
When comparing Sirui 135mm T2.9 1.8x (Sony E Mount) and Sony FE 400 mm f2,8 GM OSS, which one is better?
1. Lens Mount Comparison
These two lenses use the same lens mount, the Sony E. This means that both lenses are compatible with cameras that use this mount.
Winner: Tied
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 Sony FE 400 mm f2,8 GM OSS has the largest aperture of the two lenses at 2.8 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 Sony FE 400 mm f2,8 GM OSS wide open, and therefore it might be a better lens in dark situations.
Winner: Sony FE 400 mm f2,8 GM OSS
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 Sony FE 400 mm f2,8 GM OSS and Sirui 135mm T2.9 1.8x (Sony E Mount):
| Sony FE 400 mm f2,8 GM OSS | Sirui 135mm T2.9 1.8x - (Sony E Mount) | |
 |  | |
| Brand | Sony | Sirui |
| Weight | 2895 g | Missing |
| Lens Mount | Sony E | Sony E |
| Focal Length | 400 mm | 135 mm |
| Largest Aperture | 2.8 | 2.9 |
| Anamorphic | No | Yes |
| Anamorphic Squeeze Factor | Missing | 1.8 |
| Minimum Focus Distance | 270 cm | Missing |
| Type | Prime | Missing |
| Aperture Range | 2.8 - 22 | Missing |
| Filter Thread Diameter | 40.5 | Missing |
| Aperture Blades | 11 | Missing |
| Lens Groups | 23 | Missing |
| Lens Elements | 17 | Missing |
| Image Stabilization | Yes | Missing |
| Autofocus | Evet | Missing |
| Macro | No | Missing |
| Weather Seal | Yes | Missing |
| Full Frame Coverage | Yes | Missing |
| Lens Hood Included | Yes | Missing |
| Stabilization Type | Sony Optical SteadyShot (OSS) | Missing |