In optical jargon, F stands for “focal ratio”. As an example – in your class there are 12 boys and 14 girls. A ratio is used to show the relationship between two numbers. In math, a ratio is written using the : (colon symbol). If we mount a longer lens, the view will be magnified (telephoto).į:2.6 is a ratio. If we mount a shorter lens, the view delivered will be “wide-angle”. Meaning the view matches what we see with our own eyes. These are significant facts because if we fit a lens with a focal length about equal the corner-to-corner measure of the image sensor, the view resulting will be “normal”. In other words, does the lens operate as a wide-angle, or telephoto, or does it deliver a “normal” view of the world. It reveals the properties of the lens such as how big images of objects will be and as well as the angular field of view. The focal length is the most important fact about a lens. This lens has a focal length of 3.8mm (about 1/7 of an inch) about the height of three stacked pennies. We call this distance the “focal length”. The shape of the lens regulates the distance lens to projected image. Now they project an image of the outside world onto the surface a digital image senor (or film) located inside the the rear of the camera. The lens causes these rays to travel taking on a converging path. As these rays traverse the lens their path is changed. It gathers light rays stemming from object. The camera lens is a copycat of the human eye. That is backwards.į:2.6 f=3.8mm engravings on the lens - what they mean. It seems their marketing department needs to learn how the focal length works, since this diagram shows a longer focal length as wider. If you never ever need the zoom than this is probably fine. Even a used old camera is probably better, if you ever need the zoom. My advice is to look for something with optical zoom. The result will be, let's just say, not what you hoped for if you use the digital zoom. After googling I see that the 35mm equivalent is a 37 mm lens.Īlso note that the camera only has digital zoom. In this case 3.8 mm needs to be multiplied with the crop factor of the sensor if you want to get the "35 mm equivalent". This is the number that describes if it's a wide angle lens (like a GoPro) or a telephoto lens (like sports and wildlife photographers use). The f=3.8 mm is the focal length of the lens.
A lower number means more light can hit the sensor.Ī lower number also means you can easier get the background out of focus. The F 2.6 is the f-stop, "speed" or how light sensitive the lens is.
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