How to adjust parameters when SLR cameras use M-files? This is D3300. Sunny days need apertures and shutters. What's the ios number? What about cloudy and rainy days?

Use IOS 100, shutter 100, sunny aperture 16, sunny1,cloudy day 8, cloudy day 5.6. According to this standard, the shutter is higher, the IOS is higher or the aperture is larger. Specific standards are introduced in old photography books. This method of artificially estimating the exposure of light is called guessing light, which is often used in situations where there is no exposure meter or snapshot. Your digital SLR has an exposure scale, which can help you adjust it accurately.