Canon EF-S 24mm f2.8 STM

Canon EF-S 24mm f/2.8 STM — compact, wide range, fixed focal length lens for Canon digital single-lens reflex cameras.

The lens construction has a system for smooth, quiet focusing, so the lens allows to create a video without noticeable noise using auto-focus system. Optimized lens mechanism reduces flares and chromatic aberrations in images. A small focal length allows to make macro shots with the lens from a minimum distance of 16 sm. The price of the lens varies 170 US dollars, so it is a budget lens.

Feel free to discuss this lens, ask questions on usage of it and post your all messages on the topic at discussion page of the article

Advantages
The most important advantages of this lens are following:
 * Compact size and weight - you can have camera in small bags, cases, backpacks due to lens size and the total weight of camera with the lens allows to have it during long trips by walk;
 * The maximum aperture size - because of sufficiently aperture size (f2.8) lens allows to make pretty high-quality images in dark rooms or at night without a flash and fixing camera on tripod;
 * The metal bayonet allows securely attache the lens to the camera, making the entire structure resistant and durable;
 * Justified ratio of price and quality. This budget lens makes photos with good quality: pretty sharp and clear images;
 * Suitable for full-frame and non full-frame cameras;
 * Excellent lens for panoramic shooting;

Disadvantages
The disadvantages of the lens include the following: Such disadvantages are wide spread among many budget lenses. This effects are barely noticeable, and they can be easily corrected by any photo editor.
 * Lens distortion - this effect is hard to detect on images made with this lens. If there is a distortion so it can be easily corrected with special programs for image editing;
 * Not very fast auto focus in dark conditions - Auto focus speed of the lens is often not so fast;

Lens focal length
The focal length of this lens is 24 mm, so the viewing angle equals about 59º10' and that matches with the human eye viewing angle. It is possible to make quite good images in small rooms, landscape and panoramic images as well as portrait photos due to such focal length characteristics. See below the samples of all this kind of photos made by Canon EF-S 24mm.

Lens focusing
Canon EF-S 24mm f/2.8 STM has a quite thin ring for manual focusing which is not so convenient to use to make a proper focus on some object. Canon company suppose that the most of customers of Canon lenses use manual focusing very rarely that's why the company decided to make construction very simple.

Auto focussing of Canon EF-S 24mm lens operates very fine and it takes about 0,15 to focus on some object. The speed of auto focusing can satisfy almost everyone, but please not that it can be a little bit slower and incorrect during dark conditions. Focusing operates soundless due to lens STM system (Stepper motor) so that's why the lens is very good in comparison price / quality.

Lens chromatic aberrations
Chromatic aberrations — also known as "color fringing" or "purple fringing", is a common optical problem that occurs when a lens is either unable to bring all wavelengths of color to the same focal plane, and/or when wavelengths of color are focused at different positions in the focal plane. Chromatic aberration is caused by lens dispersion, with different colors of light traveling at different speeds while passing through a lens. As a result, the image can look blurred or noticeable colored edges (red, green, blue, yellow, purple, magenta) can appear around objects, especially in high-contrast situations. This effect also can be detected at Canon EF-S 24mm lens. The samples of it can be watched below:

Lens bokeh
Bokeh — part of ​​the photo which is out of focus of an object. This effect usually occurs when an object located in front line of the image and a background is out of the focusing area. Each lens has its technical characteristics to make bokeh effect in different ways. Generally this effect doesn't effect on photo quality significantly. The more opened aperture makes more blurred background of the photo, but in this case image sharpness can be reduced.

Bokeh effect can be seen at macro photo shooting and portrait photography, especially if lens is set to maximum aperture, but may slightly decrease the overall sharpness of photo. See examples Canon EF-S 24mm f / 2.8 STM bokeh effect below in the photo gallery of macro images.

Other characteristics
Lens distortion and vignetting