I merely wanted to confirm that a 100mm macro lens is just
another 100mm lens, with a really small MFD. But comparing the
100mm macro with the 135mm at the same framing, DoF should be
less with the 100mm macro. +1 but at the same aperture. Focal
length: 135 Focus distance: 10 meters (to get 2X magnification)
Total Depth of field: 0.97m Focal length: 100 Focus distance:
6.75 (to get 2X magnification) Total Depth of field: 0.81m Your
math is wrong. 135mm at 10 m will have a wider FoV than 100mm at
6.75 m. For the same framing as 135mm at 10 m, the 100mm lens
would be at a distance of 7.4 m [i.e. 10 m / (135mm/100mm)].
When you plug those numbers into your DoF Calculator of choice,
you will find that for the same aperture the DoF is identical.
Here's the way it works: when comparing on a given sensor size
(so we can ignore the circle of confusion), three factors
determine DoF. - Aperture: wider = shallower - Focal length:
longer = shallower - Subject distance: closer = shallower When
you are talking about the sa