Shutter, aperture, and sensitivity are the fundamental operations of photography, and it's important to grasp their settings and how they interrelate.

1. Shutter

The camera shutter functions as a tool to manage exposure time. Think of it as a tiny dark room with a window – it determines how long sunlight can pass through that window. This is essentially what the shutter does.

In photography, exposure refers to capturing and freezing a moment in an image. The shutter regulates exposure time. A fast shutter instantly captures an image, avoiding blurriness.

On the other hand, a slow shutter, with an extended exposure time, captures the trajectory of moving objects, resulting in a natural blur in the photograph.

To prevent blurriness, the shutter needs proper adjustment. Cameras have a "safe shutter speed." When using a full-frame camera, the safe speed is the reciprocal of the focal length. In simpler terms, your shutter speed should not drop below 1/35 second when taking handheld pictures to avoid blurring.

Keep in mind, that the "safe shutter speed" serves as a reference. Faster shutter speeds minimize the risk of handshake-induced blurriness. For creative tasks like capturing light trails, a tripod is essential.

2. Aperture

In reality, the aperture comprises adjustable metal sheets within the lens that form a hole. Adjusting this aperture hole's size controls the light reaching the camera's sensor.

In simpler terms, the aperture's size influences the amount of light entering the camera. Cameras rely on the concept of small hole imaging, akin to having cardboard with small holes on a wall, with the wall representing the light-sensitive component.

Unlike fixed holes, a camera's aperture hole is variable, allowing aperture size adjustment.

Aperture size is denoted by "f/value." A lower value after "f/" corresponds to a wider aperture, while a higher value indicates a smaller aperture. For instance, f/4 has a larger aperture than f/8.

The formula for aperture f-value is lens focal length divided by aperture diameter. Notice the relationship: these values change by a factor of 1.4.

With other settings constant, a larger aperture yields a brighter image. More light exposure per unit of time results in a brighter image.

Conversely, the shutter and aperture have optimal values. In various aperture settings for a lens, one setting typically presents better image quality – often around the middle aperture level (e.g., f/8, f/11).

Adjusting the aperture not only controls brightness but also influences imaging quality and the sought-after bokeh background effect.

3. Sensitivity (ISO)

ISO, or sensitivity, pertains to how light-sensitive the camera's element (CCD/CMOS) is. Higher ISO values correspond to heightened element sensitivity.

Like shutter and aperture, ISO also employs numerical levels – 100, 200, 400, and so forth. The ISO value can be calculated using the formula: ISO = 0.8 / exposure.

However, maintaining photo quality necessitates avoiding excessively high ISO settings.

In essence, the shutter controls exposure time, the aperture governs light entry, and sensitivity determines the level of light sensitivity. These elements jointly impact correct exposure and overall photo brightness.