The Portrait mode on the iPhone utilizes the depth information from the dual-camera system to create a depth-of-field effect, blurring the background and keeping the subject in focus. The 0.5x ultra wide-angle camera does not capture depth information in the same way as the main wide-angle and telephoto cameras, so it cannot be used for Portrait mode. The depth information required for Portrait mode is primarily captured by the main wide-angle camera, which is why the feature is not available when using the ultra wide-angle camera.

The standard lens of the Raspberry Pi Camera V2 has a 62.2-degree diagonal field of view. This wide-angle lens allows for capturing a broad perspective in images and videos. It is a popular choice for various applications such as surveillance, photography, and video streaming due to its versatile field of view.

I would recommend the Nikon AF-S DX NIKKOR 10-24mm f/3.5-4.5G ED lens for the Nikon D5300 DSLR camera. This wide-angle lens offers a versatile focal length range, allowing you to capture expansive landscapes and architecture. It also features Nikon's Silent Wave Motor for fast and quiet autofocus, as well as Extra-low Dispersion (ED) glass elements for improved image quality. Overall, it is a great choice for wide-angle photography with the Nikon D5300.

For landscape photography, a camera with a high resolution sensor and wide dynamic range is ideal to capture the details and colors of the scenery. A full-frame DSLR or mirrorless camera with a wide-angle lens would be a good choice for capturing the vastness of landscapes. For street photography, a compact and discreet camera with fast autofocus and good low-light performance is preferred. A mirrorless camera with a prime lens or a high-quality compact camera would be suitable for capturing candid moments and street scenes without drawing too much attention.

Yes, there are webcams available without a wide-angle lens. Some webcams are designed with a standard lens that captures a narrower field of view compared to wide-angle lenses. These webcams are often used for specific purposes where a wide-angle view is not necessary, such as video conferencing or live streaming from a fixed position. Users can choose webcams with different lens options based on their specific needs and preferences.

A macro lens is typically the best choice for product photography. Macro lenses are designed to capture small subjects with great detail and clarity, making them ideal for capturing the intricate details of products. They also have a close focusing distance, allowing you to get up close to the product for detailed shots. Additionally, a lens with a focal length between 50mm and 100mm is recommended for product photography as it provides a natural perspective and minimizes distortion.

A prime lens with a focal length between 35mm and 50mm is typically considered suitable for street photography. These lenses offer a natural field of view that closely resembles what the human eye sees, making them great for capturing candid moments in urban environments. Additionally, prime lenses are often compact and lightweight, which is ideal for street photographers who need to move quickly and discreetly. Overall, a 35mm or 50mm prime lens is a popular choice among street photographers for its versatility and ability to capture authentic moments.

A wide-angle lens typically has a focal length that is shorter than a standard lens, allowing it to capture a wider field of view. The lens is designed with a wider angle of view, which allows it to take in more of the scene in front of it. This is achieved through a shorter focal length and a wider lens element, which allows more light to enter the camera and creates a wider perspective in the resulting image. Wide-angle lenses are often used for landscape photography, architecture, and interior shots, where capturing a broader view is desired.