Depth of Field – Full frame sensor versus Cropped Frame APS-C sensor
Many of us love the blur out of focus background of the lens we called ” bokeh” normally generated by very wide open aperture like f/2.8, f/1.8 or even f/1.4 .
However, those lenses are not always cheap (except the 50mm f/1.4 or f/1.8). They do however create very beautiful blur out of focus background if used properly just like the image above.
The effect of the low wide open aperture lenses are even better when attached to the FULL Frame sensor camera. Here is an example of a 50mm f/1.4 lens used on a FULL frame body (left) and on the APS-C body (right). Notice the picture on the right is cropped even-though the distance of the subject was the same. This is called the cropped factor.
How to get ” Bokeh” on APS-C camera ?
There are APS-C lenses with very low aperture such as the Nikon 35 mm DX f/1.8 G . They give less depth of field when used wide open at f/1.8. (But note that the APS-C lenses cannot be used on the full frame body).
If you have APS-C body, the easiest way is to get the ” Bokeh” is either use an APS-C lens with low aperture like f/1.8 or f/2.8 or get a full frame low aperture lens with the same low aperture. Although the effect may not be of much difference between the two lenses, just in case you want upgrade to full frame body one day, you can use the full frame lens.
Benefit of FULL Frame sensor
Full frame sensor is no doubt more expensive, heavier but it has better performance in high ISO and low light. If you don’t need those features, stay with the APS-C sensor.
Example of Full frame sensor from Canon would be EOS 1 DX, 5DMIII, 6D and Nikon will be D3, D3s, D800, D600.
Example of APS-C camera from Canon would be 7D,700D, 650D and Nikon D5200, D7000.
Which camera is better for you ? Depends on what you look for.