The water level in a Bain-Marie should be filled to about halfway up the sides of the inner cooking container. This allows for gentle and even heating of the food without the risk of the water boiling over and into the food. It's important to monitor the water level during cooking to ensure it doesn't evaporate completely and cause the Bain-Marie to overheat. **

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 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. **

For animal photography, a camera with a fast autofocus system and high burst rate is essential to capture fast-moving subjects. A good choice would be a DSLR or mirrorless camera with at least 20 megapixels for high-quality images. As for the lens, a telephoto lens with a focal length of 70-200mm or longer is recommended to get close-up shots of animals without disturbing them. Additionally, a lens with image stabilization can help reduce camera shake when shooting handheld in low light conditions. **

For wildlife photography, a camera with a fast continuous shooting speed, high resolution, and good low-light performance is ideal. Cameras like the Canon EOS 90D, Nikon D500, or Sony Alpha a6600 are popular choices. When it comes to lenses, a telephoto lens with a focal length of at least 300mm is recommended to capture distant wildlife without disturbing them. Lenses like the Canon EF 100-400mm f/4.5-5.6L IS II, Nikon AF-S NIKKOR 200-500mm f/5.6E ED VR, or Sony FE 200-600mm f/5.6-6.3 G OSS are great options for wildlife photography. **

The best camera for wildlife photography is typically a DSLR or mirrorless camera with a high resolution sensor, fast autofocus system, and good low-light performance. Popular choices include the Canon EOS 5D Mark IV, Nikon D850, or Sony A7R IV. For lenses, a telephoto lens with a focal length of at least 300mm is recommended for capturing wildlife from a distance. Some popular options include the Canon EF 100-400mm f/4.5-5.6L IS II, Nikon AF-S 200-500mm f/5.6E ED VR, or Sony FE 100-400mm f/4.5-5.6 GM OSS. Ultimately, the best camera and lens will depend on your budget, specific needs, and personal preferences. **

Centrifugal force is considered a fictitious force because it only appears to act on objects in a rotating reference frame, such as a spinning carousel or a turning car. In reality, the object is moving in a straight line, but it appears to be pushed away from the center of rotation due to inertia. On the other hand, centripetal force is a real force that acts towards the center of rotation, keeping an object moving in a circular path. This force is necessary to maintain the object's curved motion and prevent it from moving in a straight line. **

One can do moon photography with a Lumix MFT camera using a telephoto lens with a focal length of at least 200mm. This will allow for capturing the details of the moon's surface and its craters. Additionally, using a teleconverter can further extend the focal length for even closer shots of the moon. It's important to use a sturdy tripod to minimize camera shake and achieve sharp images. **