300mm zoom lens equivalent

The zoom lens is the lens that allows changing the focal length of the lens by a wide-angle zoom and zoom into a narrower angle for easy shooting from a standing position can expand or narrow the angle, taking to frame more or less scenery. The bigger zoom lens, the image will become more clearly visible.


In other words, Zoom lens is a set of lenses which put together and have the ability to change the focal length (as opposed to the original lens with constant focal length). Zoom lenses are often used in cameras, camcorders, some binoculars, microscopes, telescopes, and other optical instruments.

Some advantages when using 300mm zoom equivalent:

– Lens with a focal length to help people capture from afar – and very far with very long focal length – close-ups (zoom) subjects want to capture  that are not approaching the subject (or can not be approached because a certain reason)

Boat on the sea – very difficult to capture without the zoom lens.


A photograph has extensive background (using short telephoto lenses) can tell viewers know a lot about the environment, the landscape and the circumstances of the main subject, but on the contrary, if using artless, can make the viewer lose focus on the main subject by the more redundancy, which overshadowed the main subject and not giving an impression to the subject. Focal length – with a narrow picture angle – to help focus the attention of the viewer to the main subject by removing fewer details surrounding the subject in the background, making the subject in the photograph is more noticeable.

    Blurred background photo makes the main character was noticed.



These lenses to bring convenient, versatile shooting, very suitable for the photographs of family or tourism. The large zoom lens also helps photographers not to carry multiple lenses at once, and avoid work “risky” as to replace removable lens while shooting.

With the advantages that the lens magnification will promote best when close-up photography, landscapes, portraits and especially about wildlife, animals, …

Focal length is suitable for shooting sports and wildlife often much longer, at least 200 mm, 300 mm or ideally more. Professional photographers shooting sports and wildlife often use 600 mm tube length even further.

Using 300mm zoom lens equivalent to taking the high difficulty level images such as birds flying in the sky


Some disadvantages:

Focal length can lose the circumstances surrounding elements of the subject, that makes subject “lonely” and loses significant association between these factors may be necessary for the photo.

Should you use a 300mm zoom lens equivalent?

For novice photography: it is very suitable and convenient.you should visit the tourist spots to show your abilities.

For professional photographer: you should still use a 300mm lens focal length equivalent to taking pictures outdoor scenes, difficult pictures as wildlife or moving objects such as children play on the grass or play football athletes on the field.

300mm zoom lens equivalent is suitable for both novices and professional photographers.


How to choose a good zoom lens?

Look at the focal length of the lens body: the most appropriate focal length is 70-300mm, also can type up to 400mm focal length. It is suitable for all kind of camera, and it is suitable for all photographers are a novice or skilled because we can zoom from most normal level to the highest level of the lens.

A zoom lens


Aperture is denoted as f/number. It is the ability to perceive the light of the lens, The larger the aperture, the more light in, and better in low light conditions. The lens has a large aperture gives you the clear picture , better background blur. Zoom lenses obviously benefit large, but attached to it is the size of the lens and the lens must be larger, heavier and more expensive.


(link:http://pixelarge.com/wp-content/uploads/2014/09/what-is-aperture.jpeg )

The relation between opening of the aperture blades and f-stops

(link:http://pixelarge.com/wp-content/uploads/2014/09/lens-aperture-f-stop.jpg )

Some kind of common zoom lenses 300mm equivalent today:

Canon EF 70-300mm f4-5.6 IS USM


AF Zoom-NIKKOR 70-300mm f/4-5.6G:


Although in fact, creativity is absolutely no limit, and in theory the photographer can use any focal length to capture any image category depending on your individual creativity, has the focal range to serve this purpose more than for other purposes, such as the ultra-wide angle lenses are often used for capturing vast landscapes or buildings, as well as the lens focal length of about 300mm zoom equivalent is used to capture wild animals. The following table indicates the most common uses, the most common of the large focal range.

Fx full size Dx Crop
85-135mm (1), (2), (4) (1), (2), (4)
135-200mm (1), (2) (1), (2)
200-300mm (1), (2) (1), (2), (3)
300-400mm (2), (3) (3)
Over 400mm (3) (3)
  1.     Narrow landscape, close-up
  2. Portraits, face specification
  3. Birds, animals, wildlife
  4. Insects, bees, butterfl