Many people claim that cropped sensors are actually better than full frame and larger sensors for macro applications.
Here is an example:http://www.43rumors.com/micro-four-thirds-and-macro-photography-by-eugene-kitsios/
Their argument is that for macro photography DoF is the limiting factor. They say that to get the same DoF, the larger the sensor, the smaller the aperture needs to be, which would offsett the light gathering capacity of larger sensors.
As an example, if we compare full frame vs. 4/3 sensors:
- full frame is roughly four times larger than 4/3 (measuring the surface), thus has virtually a two stop advantage in terms of light gathering capacity;
- anyhow, if with four thirds sensor we need to close the aperture to f/8, then on a full frame sensor we would need to close the aperture at f16 to get the same DoF, thus loosing two stop of light (offsetting completely the larger sensor advantage).
I am not sure if the second point is correct. The comparison shall be done considering different lenses on the two systems:
- if we use a 50mm macro on the 4/3 sensor, for correct comparison (to get the same angle of view), a 100mm lens should be used on the full frame (I know there would be slight differences in the final image due to the different aspect ratio).
I am skeptical about the above argument, anyhow I am unable to tell why it would be wrong.
What do you think, is really a crop sensor better than full frame for macro photography? Or is the full frame better? In the latter case, can you explain why?