Understanding Field of View with a 45mm Mirrorless Camera Lens
For those interested in photography, the field of view (FOV) is a critical factor that determines the image captured by your camera. Understanding this concept is especially important for users of mirrorless cameras, as the field of view can vary significantly depending on the sensor size. In this article, we will discuss the characteristics of a 45mm lens on a mirrorless camera, and how it affects the field of view.
What is a 45mm Lens?
A 45mm lens, whether used on a mirrorless camera or a DSLR, is a fixed focal length lens. Often referred to as a prime lens, a 45mm lens does not offer zoom capabilities. Zoom lenses, on the other hand, have a specified focal length range (such as 35–105mm) and a zoom ratio, which is the ratio of the longest focal length to the shortest focal length (in this case, ( frac{105}{35} 3 )).
Field of View and Sensor Size
The field of view (FOV) of a lens is greatly influenced by the sensor size of the camera. Different camera systems have different sensor sizes, which affects the FOV of equivalent lenses. Let's break down the aspect for both Micro Four Thirds (MFT) and Full Frame sensors.
Micro Four Thirds System
On a Micro Four Thirds (MFT) system, a 35–105mm lens typically offers a diagonal field of view ranging from 7° to 34°. This wide range is due to the variable focal lengths of the lens. However, when we look specifically at a 45mm lens, the FOV is notably narrower. For a 45mm lens, the diagonal field of view on an MFT sensor is approximately 20° to 22°. This means that the 45mm lens captures a more narrow angle of view compared to a 35mm lens, which would typically provide a diagonal field of view of around 34°.
Full Frame Camera
On a full frame sensor, a 45mm lens will provide a significantly broader field of view. The diagonal field of view for a 45mm lens on a full frame sensor is approximately 44°. This is much wider compared to the MFT, making the full frame sensor’s 45mm lens a more versatile option for capturing scenes with a wider perspective.
Practical Considerations and Usage Recommendations
While the concept of field of view is important, it can be challenging to guess the exact angle of view just by looking at the focal length. Therefore, it is recommended to experiment with the lens on your specific sensor type to determine the perfect focal length for your needs. For example, if you are more interested in capturing close-up details with a more narrow field of view, you might want to use a 45mm lens on a full frame sensor for its broad FOV. Conversely, if you prefer a more controlled and detailed shot, the 45mm lens on an MFT sensor can offer a more focused and intimate perspective.
Conclusion
In summary, a 45mm lens provides a specific field of view that is influenced by the sensor size of your camera. Understanding the differences in field of view between MFT and Full Frame sensors can help you choose the right lens for your photography needs. Experimenting with the lens on your camera will provide the best understanding of its capabilities in different scenarios.