Light Transmission Comparisons
Theoretically, all lenses, when set to the same f/stop, should deliver the same amount of light to the film/sensor. In practice, there are differences in effective light transmission, due to different optical designs, and different materials and coatings.
Below find a table of observations of differences between lenses. Since most of us don't really have the equipment to do these tests scientifically, we'll do them in terms of comparisons between lenses.
Rules:
- Shoot under the same conditions
- At the same subject
- At the same or similar focal length
- With the same settings. (Meaning, bracket shots with each lens covering the same range of settings, adjusting ISO or shutter consistently.)
| Lens 1 | Lens 2 | Results | Observer | Sample Set/Thread |
| 35mm f/2 O | 35mm f/1.4 AIS | 35mm f/1.4 AIS 2/3 stop faster at f/2 | Kukkurovaca | Link |
| 50mm f/1.4 S | 35mm f/1.4 AIS | 35mm f/1.4 AIS slightly faster at f/1.4 | Kukkurovaca | Link |
| 105mm f/2.5 K | 55-200 VR | 55-200 VR roughly 1/3 faster at f/5.6 | Kukkurovaca | Link |
| 50mm f/1.8 AF-D | 18-55 | 18-55 faster at f/5.6 | Eddie Barksdale | Link |
| 180mm f/2.8 P | 55-200 VR | At f/5.6, minimal difference. At f/11, 55-200 somewhat (1/2-stop?) faster. | Kukkurovaca | Link |
| 35mm f/2.8 S | 50mm f/1.8D | 50mm f/1.8D roughly 1/2 stop faster at f/2.8 | David Chu | No Pictures |
| 50mm f/1.4 S | 50mm f/1.8D | f/1.8D very slightly (less than 1/3 stop) faster at f/2. | Kukkurovaca | Images pending |
| 35mm f/1.4 AIS | 50mm f/1.8D | 35mm f/1.4 as fast at f/2 as the 50mm f/1.8 AF-D at f/1.8. | Kukkurovaca | Images pending |
| 300mm f/4.5 Late non-AI | 400mm f/5.6 ED AIS | Very little, if any, difference in transmission | Kukkurovaca | Images pending |
page revision: 8, last edited: 12 Aug 2009 20:07
