Why an APS-C Camera Sees Less than a Full Frame Camera with the Same Lens

When it comes to photography and videography, understanding the differences between full-frame and APS-C cameras is crucial. A full-frame camera, named for its sensor being the same size as a frame of 35mm film, has a sensor 1.6 x 1.6 larger than an APS-C (Advanced Photo System - type C) camera. This results in a 2.56 times greater area for capturing images. But what does this mean for the field of view or the angle of view that these cameras offer?

Understanding Sensor Size and Field of View

To grasp why a full-frame camera captures more area compared to an APS-C camera, it's essential to understand the concept of the image circle projected by a lens. A lens, regardless of the camera body it's attached to, projects an image in a circular form. The full-frame camera's larger sensor can encompass more of this image circle, while an APS-C camera captures only the center portion. This is because the APS-C sensor is 'cropped,' hence the name APS-C - it simply captures a cropped view of the image circle.

A Simple Demonstration

To visualize this phenomenon, imagine an A4 piece of paper as a reference to a full-frame 35mm sensor. If you project your hand's shadow using a torch onto the A4 paper, the entire paper will be covered by the shadow. This simulates how a full-frame camera sees the entire image circle projected by the lens.

The APS-C Perspective

Now, if you use the same A4 paper but cut it down to a much smaller size, for example 50% or 60% of the original size, the shadow will only cover the palm portion of your hand. This smaller piece of paper represents an APS-C sensor. Essentially, only the central portion of the image circle is captured by the APS-C sensor, resulting in a narrower field of view or angle of view.

Technical Aspects of Sensor Size

A given lens will project an image circle on the sensor plane. A smaller sensor, such as an APS-C, will capture only a portion of that image circle, typically the center. This phenomenon is known as a crop factor. In the case of APS-C sensors, they usually have a crop factor of 1.5 to 1.6 relative to full-frame sensors, leading to a narrower field of view for the same lens.

Implications for Photography and Videography

The effect of sensor size on the field of view has significant implications for photographers and videographers. For instance:

Depth of Field: Full-frame cameras offer a shallower depth of field than APS-C cameras with the same lens and settings. This means that full-frame cameras are better for isolating subjects from backgrounds. Fisheye vs Standard View: Full-frame cameras provide more of the image circle, which means a photographer can capture more of the scene, especially when using wide-angle lenses. This is ideal for landscapes and architecture photography. Panoramas: Full-frame sensors can capture wider panoramas due to their larger coverage area.

Conclusion

In conclusion, the difference in sensor size between full-frame and APS-C cameras significantly affects the field of view. Understanding this concept is crucial for making informed decisions when choosing the right camera for your needs. Whether you want a wider angle or a more narrow view, knowing how each camera frame size impacts your photography can help you capture the exact type of images you envision.

Keywords: full frame camera, APS-C camera, field of view