The larger lens has more area to collect light, which actually equates to an image more then twice the brightness at a ratio equal to πr² where r equals the radius of the lens. The image would, however, be no larger since the focal length of the lens is that same.
So, how do different camera lenses affect photo quality? The camera lens has a greater impact on the photo quality than for example megapixels because a camera lens has a direct effect on the background blur, sharpness, level of detail, depth of field and these are just some of the more important parameters.
The diameter of a lens will relate to the focal length, aperture, and what the final imaging circle must be. Generally speaking the more glass(in size or total elements) you have the better a job that can be done redirecting that light without flaws.
When you pay more money for a lens, you're buying features such as build quality, weatherproofing, wider maximum apertures, and improved autofocus—as well as an improvement in image quality. These features are all important, but in practice you may not notice much difference in the final image quality.
Camera Lens Characteristics
The focal length range of a lens is expressed by a number, and that number tells you how much of the scene your camera will be able to capture. Smaller numbers have a wider angle of view and show more of the scene; larger numbers have a narrower angle of view and show less.
The focal length of your film or digital camera lens dictates how much of the scene your camera will be able to capture. Smaller numbers have a wider angle of view and show more of the scene, while larger numbers have a narrower angle of view and show less.
The speed of a lens is determined by its aperture. Fast lenses offer wide apertures, such as f/2.8 and up, while slow lenses usually only support up to f/4. The wider the aperture, the better the lens will perform in low light conditions, and the narrower the depth of field you'll be able to achieve.
Well the standard lens test is based on what's know as 'optical metric scores' which are standard measurements used to rate the performance of a camera lens, such as its sharpness, distortion, vignetting, transmission and chromatic aberration (see image above).
As the focal length value decreases, the lens becomes a wide-angle lens, and as the value increases it becomes a telephoto lens. The brightness of a lens is decided by a combination of focal length and lens diameter. If the focal length of two lenses is the same, the lens with the larger diameter will be brighter.
From Longman Dictionary of Contemporary Englishlens /lenz/ ●●○ noun [countable] 1 the part of a camera through which light travels onto the surface where the image is recorded a standard 50 mm lens → telephoto lens, wide-angle lens, zoom lens2 a piece of curved glass or plastic which makes things look bigger, smaller, ...
The explanation is quite simple – light enters the front lens element through different angles and gets reshaped by other lens elements inside the lens. Hence, it does not affect the image.
Camera lenses are more important than the camera they're attached to, at least in most situations. An entry level DSLR with a great lens will take great photos while a $10,000 professional camera with a terrible lens will take terrible pictures.
An STM lens uses one type of autofocus system, while a USM lens uses another type of autofocus system. These designations have nothing to do with optics, and the image quality of an STM lens vs a USM lens will be completely unaffected.
While a larger aperture diameter might increase the brightness and sharpen the focus, increasing the lens magnification will increase the focal length and thus enlarge an image.
In most photography and all telescopy, where the subject is essentially infinitely far away, longer focal length (lower optical power) leads to higher magnification and a narrower angle of view; conversely, shorter focal length or higher optical power is associated with lower magnification and a wider angle of view.
Lens thickness may dictate your frame style. Thick lenses may distort the appearance of your eyes and face. Thick lenses can add a lot of weight to your eye-wear frame. Strong myopia prescriptions can lead to exceptionally thick lens edges.
The lens is the camera's most important part. More than any other camera component, the lens determines the quality of the image. The most important part of a camera is its lens since the quality of an image is so dependent upon it.
If you want to fit more into your frame, you might want to look into wide-angle focal lengths: 14mm, 20mm, 24mm, 28mm, and 35mm. On the other hand, if you want to get as close as possible to your subject, go for a telephoto lens with focal lengths that usually range from 50 to 100mm.
The more curved the surface of a lens is, the more it refracts the light that passes through it. There are two basic types of lenses: concave and convex. The two types of lenses have different shapes, so they bend light and form images in different ways.
The sharpness of a lens isn't constant; it changes with aperture, focal length (if it's a zoom lens) and the subject distance.
Changing the focal length changes the angle of view. The shorter the focal length (e.g. 18 mm), the wider the angle of view and the greater the area captured. The longer the focal length (e.g. 55 mm), the smaller the angle and the larger the subject appears to be.
Wider angle lenses (shorter focal length) require that the portrait be taken from closer (for an equivalent field size), and the resulting perspective distortion yields a relatively larger nose and smaller ears, which is considered unflattering and imp-like.
If you notice your Canon digital SLR camera lens has the letters USM written on the side, it means the lens has a small motor built into the body. Hence, USM is short for Ultra Sonic Motor. What this means is that your lens will autofocus faster than standard models.
USM. USM (Ultrasonic Motor) is the most widely used AF motor type in the Canon EF lens range to date. Common to all USM motors is the fact that that they convert ultrasonic vibration energy into rotational force to move the lens.