A 4 cm tall candle is placed in front of a double convex lens. The lens has a focal length of 15.2 cm. The object has been placed 45.7 cm from the vertex….The following video explains the thin lens formula:

A concave lens is a lens that possesses at least one surface that curves inwards. It is a diverging lens, meaning that it spreads out light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia).

Concave mirror is used by dentist, solar furnace, reflector of a torch, etc. Convex mirror is used in rear view mirrors.

How to Pick the Right Camera Lens to Fit Your Needs

1. Aperture. Maximum aperture is stated on all lenses.
2. Focal Length. The first thing to consider when choosing your new lens is the focal length.
3. Fixed or Zoom. For most, the most appropriate choice would be a zoom lens.
4. Crop Factor.
5. Image Stabilization.
6. Color Refractive Correction.
7. Distortion.
8. Perspective / Focus Shift.

Lenses can be classified into subgroups like prime, macro, wide angle, normal, telephoto, and zoom lenses. They’re also rated in regards to f-stop or speed. An example would be a 50mm f/2.0 lens or an 80mm f/1.4 lens.

The four major types of lenses are the short-focal-length lens, the middle-focallength lens, the long-focal-length lens, and the zoom lens.

The two most common types of lenses are concave and convex lenses, which are illustrated below in Figure 1. A common bi-convex lens is considered a positive lens because it causes light rays to converge, or concentrate, to form a real image.

The two main types of lenses are: Convex Lens (Converging) Concave Lens (Diverging)

Better quality lenses tend to have a larger aperture, allowing more light to pass through to the sensor. The aperture size is measured as an f-stop. Confusingly, the larger the maximum aperture of the lens, the smaller the f-stop. Faster lenses are key to capturing sporting events and wildlife.

While lens attachments expand the capabilities of your camera, allowing you to take more interesting shots, they don’t necessarily improve the overall image quality your smartphone camera is able to produce—that is, your 8-megapixel camera isn’t suddenly going to produce 12-megapixel photos.

In photography, we strive to take “sharp” photos. Generally, this means that you want the subject to be in focus with clear lines, crisp details, and no (unintended) blurring. It’s a combination of accurate focus, a static camera, and the properties of the lens you’re using.