What : Cowslips at Terra Nova park in Richmond
When: 14 May 2014
Comment: This image was shot with a Canon EOS 60D DSLR using an EF70-200 mm f/4L USM lens at 70 mm and f 4.0, ISO 100, 1/1600 sec. It is impossible to achieve the out focus blur or "bokeh" shown in this image with a compact camera. Good bokeh can be produced with some compact cameras but only if the main subject is less than 20 cm from the camera - hardly a versatile capability. This ability of a DSLR in fact may the the only reason left to use a DSLR for web publishing along with maybe the use of a hot shoe for flash and remote triggering. The reason that compact cameras don't produce good bokeh are as follows:
- Point and shoot cameras have very small sensors. The size of the camera sensor is directly related to depth of field (the area of the image that appears sharp or “in focus”) – the smaller the camera sensor, the larger/greater the depth of field. When compared to film or full-frame digital cameras, point and shoot cameras typically have sensors that are 15+ times smaller in size. Because of this, the area that appears sharp is much larger in size than what it would be on a DSLR camera, making it harder to isolate the subjects.
- The lenses in point and shoot cameras are not optically designed to create good-looking bokeh and are very limited in terms of minimum and maximum apertures and focal lengths. Generally, lenses in point and shoot cameras are wide-angle and have short focal lengths to cover as much of the area as possible, which puts most of the scene in focus. Cameras with optical zoom lenses typically change apertures to a larger number when you zoom in (thus increasing depth of field), making it even harder to separate the subject from the background.
- Most point and shoot cameras are designed to put everything into focus, so that the pictures people take do not turn out to be blurry due to focus issues. That’s why most of focusing in point and shoot cameras is automated, with face and scene recognition systems specifically designed to automatically acquire focus on the right target.
Please visit https://www.photographytalk.com/beginner-photography-tips/7356-a-beginner-s-guide-to-aperture-and-depth-of-field
for further information on DOF and aperture