Specifications
Outline
Specifications



NANOHAx5(E),NANOHAx5(M)


About NANOHA F number
In NANOHA, the open F number is indicated as F11. This is large number. On the other hand, for example, Canon MPE65mm F2.8 is indicated as F2.8. So you may think it is much brighter lens than NANOHA. But it is not true. The meanings of F number are different in these lnses. In fact, NANOHA is brighter.
F number is calculated at infinity position. If you focus closer, the light to the image sensor is reduced and "Effective F number" get larger. In ordinary lenses, you don't have to think about this point so seriously. But, in macro lenses, it is not unignorable.
These are the Effective F numbers of Canon MPE65mm F2.8 in every magnifications.
Magnification  Effective F number  
1x:  F5.6  
2x:  F8.4  
3x:  F11.2  
4x:  F14  
5x:  F16.8 
Canon MPE65mm F2.8 can take pictures only in the magnification range from 1x to 5x. It means you cannot get actual F2.8 brightness at anytime. At x5 magnification, the Effective F number is larger than F16.
On the other hand, In NANOHA, the Effective F number is F11 at x5 magnification. We indicate Effective F number at x5 magnification. NANOHA is brighter than Canon MPE65mm F2.8 .
The small F number looks good. But, thinking about the fact Effective F number is much useful for ISO and shutter speed setting, we indicate Effective F number on NANOHA.