Understanding the Zoom Control Feature to make an application-specific decision

Zoom Feature

Zoom feature is among the most crucial features in many familiar embedded vision applications. Zoom used to be employed in photography to modify the noticeable range between the camera and the subject. However, the idea of zoom has gotten a little bit more nuanced with the development of digital technologies.

You have probably heard of the terms optical and digital zoom if you are searching for a camera, particularly a compact or fixed lens point-and-shoot camera. An optical zoom is utilized to capture a close-up photograph of the subject without physically getting closer. Digital zoom is a feature of digital cameras and camcorders that aids in cropping the entire image and digitally enlarging the size of the viewfinder of the required zoomed-in area.

So, in this post, you will learn everything that there is to understand about zoom, such as the different types, how they each work, and the scenarios in which it could be used.

Different Methods of Zooming in Photography

In the camera, there are two main types of zooming: optical zoom and digital zoom. While digital zoom makes use of scaling technology to magnify a portion of an image, optical zoom makes use of the physical changes in a lens to vary the distance between the camera sensor and the subject.

Digital Zoom

Digital zoom does not necessitate the use of specialized lenses. Rather than relying on lens optics, it is performed by utilizing the ISP or software. It enlarges the image on your screen as well. Digital zoom, in contrast to optical zoom, merely entails cropping the entire image and digitally enlarging the size of the viewfinder of the required zoomed-in area.

Digital zoom interpolates the output back up to the original image’s pixel dimensions while also enlarging the image’s core region to the same size as the original and maintaining its aspect ratio. As was already said, this method involves cropping, therefore the quality and resolution are reduced so that it is inferior to the original.

As earlier discussed, digital zoom can be implemented by using hardware or software. In hardware-based zoom, the Image Signal Processor (ISP) handles the zooming capability. First, the image resolution is cropped from the sensor after which the ISP resizes it. With regards to software-based zoom, the cropping and resizing are both executed in the software.

Optical Zoom

When using optical zoom, the glass components within the lens move to change the lens’s focal length.

A digital camera’s optical zoom ratio calculates how far the lens can really be zoomed in to make objects look closer. A picture may be enlarged via optical zoom while maintaining a high level of detail and sharpness.

The resolution of the image is unrelated to optical zoom since it simply enlarges the topic or the entire image to a specified range. So, the megapixel (MP) of the camera is the sole factor that affects image quality.

The camera enlarges that region to fill the whole picture frame when the zoom function is used. Both optical and digital zoom is available.

Changing the focal length and physically rotating the camera’s lenses is how optical zoom operates. To physically enlarge the subject, optical zoom lenses are extended. According to the user’s instructions, a motor regulates the lens movement.

Which Zoom Lens is Preferrable?

The ability to magnify varies among different zoom lenses. There are two primary characteristics to take into account when choosing a zoom lens. Superzoom lenses are often used to describe lenses having a very high zoom ratio.

Focal Length

Focal Length is really about how the distance between the object and the camera, which is measured in millimeters. Wide-angle lenses and telephoto lenses are at the two extremes of the focal-length range. A telephoto lens has a focal length of at least 60mm and a wide-angle lens has about at most 35mm. The focal length of a lens determines its angle of view and magnifying power. The best lenses to use for capturing objects at a distance are therefore telephoto lenses for far-off objects and wide-angle lenses for nearby objects.

Zoom factor

The ratio of maximum and minimum focal lengths is called the zoom ratio. The maximum and minimum focal lengths are the basis for how zooming in or out is controlled. The zoom ratio is more of a measurement of a lens’s adaptability than its magnification ability, is a fact then doesn’t assume that a high zoom ratio will make it possible to capture extreme close-up visuals.

Which is Better?

In a higher-rated optical zoom camera, the user may take a picture of the subject from a further distance and yet receive a crisp, close-up image. The optical zoom function is analogous to the zoom on analog cameras. Every optical zoom lens has a range, and optical zooms may alter their focal length.

One can reduce or focus the apparent angle of view of a picture using the digital zoom method. To achieve this, crop the image to a central region with the same aspect ratio as the original, and then enlarge the resulting image to match the original’s pixel size. There is no need to change the camera’s optics because this is all done electronically. The Image Signal Processor (ISP) manages the zooming functionality in hardware-based zoom. Enlarging degrades the image quality since it changes the way the camera’s image sensor originally laid out the image’s pixels.

In case of any disputes, optical zoom is recommended to digital zoom because the latter decreases image resolution and, when used excessively, produces pixilated images. For embedded camera applications, digital zoom is preferred nonetheless because it automates the operation.

Summing Up

Hopefully, this article has given you a better understanding of the differences between optical and digital zooming, allowing you to choose the one that best fulfills the requirements of your product.

Vadzo can devise and create custom color USB cameras with digital zoom features. Additionally, we can provide you with a unique camera solution. We design, develop and manufacture camera solutions for various use cases across domains such as healthcare, retail, agriculture, industrial, law enforcement, etc.

If you need assistance incorporating digital zooming into your projects using camera systems, Contact Us