减焦镜效果计算器 — 公式
## Focal Reducer Effect
A focal reducer shortens the effective focal length, widening the FOV and making the system faster.
### Formulas
**f_eff = f * R**
**N_eff = N * R**
where R is the reduction factor (e.g., 0.63).
The speed gain (for extended objects) scales as 1/R squared, because the same light is concentrated into a smaller image.
A focal reducer shortens the effective focal length, widening the FOV and making the system faster.
### Formulas
**f_eff = f * R**
**N_eff = N * R**
where R is the reduction factor (e.g., 0.63).
The speed gain (for extended objects) scales as 1/R squared, because the same light is concentrated into a smaller image.
计算示例
1000 mm f/10 scope with a 0.63x reducer.
- f_eff = 1000 * 0.63 = 630 mm
- N_eff = 10 * 0.63 = f/6.3
- Speed gain = 1 / 0.63^2 = 2.52x faster