In this article we'll talk briefly about the types of lenses and mounts on different cameras available in the market,
Types of Lenses
In this post you would get introduced to different types of lenses, based on their focal length. This would help you decide your future lenses as per your photography needs.
A Standard Lens has an angle of view similar to that of the naked eye, thus resulting in photos which matches what our eye sees. The focal length of a standard lens is 35-50mm on a 35mm film camera and a full frame DSLR camera. The standard lens is also known as 'normal lens' as the angle of view that you get through the viewfinder is normal to your eyes, as that is exactly what your eyes normally sees. These lenses are ideal for street and travel photography.
A Wide-angle lens has the focal length shorter than 35mm on a 35mm film camera and a full frame DSLR camera. The wide-angle lenses are further classified into three categories: Wide, Ultra-wide and Fish-eye lens. As the name suggests, the ultra-wide angle lenses are much wider and have focal length of 20mm or shorter, but have less distortion as compared to the fish-eye lenses. The fish-eye lenses are much wider than the ultra-wide angle lenses, and produces photos with 'fish-eye' effect which creates circular effect. Wide-angle lenses are ideal for landscape, cityscape and event photography.
A telephoto lens has the focal length longer than 50mm on a 35mm film camera and a full frame DSLR camera. These lenses help your camera to capture distant objects without going closer. Telephoto lens can help you achieve shallow depth of field, thus eliminating your subject from the background. The telephoto lenses can be used for wildlife and candid photography as it lets you get closer to the subject without moving much.
Digital SLR lens formats
In this part of the article we would be discussing about the various lens mounts available in Canon, Nikon and Sony digital SLR cameras. In all the digital SLR cameras, the camera's format refers to the size of its image sensor. The DSLR cameras can be classified into full frame and crop sensor camera formats. The full frame sensor is the larger of the two as it is of the size of a 35mm film frame.
The full frame DSLR camera has a bigger image sensor, which is approximately 36mm x 24mm in size. Featuring bigger image sensor as compared to that of a crop sensor DSLR camera, the full frame DSLR camera can cover wider angle of view. Why so? The angle of view is determined by two factors: the size of the sensor and the focal length of the lens used. The bigger the sensor, wider would be the angle of view. Similarly, the wider the focal length, the wider would be the angle of view and vice-a-versa.
As the crop sensor DSLR camera has a smaller image sensor, the angle of view would be narrower as compared to the full frame DSLR camera.
Now that we have discussed about the DSLR camera formats, let's now get to know the various lens mounts available in the market to support the respective camera format.
Nikon DSLR lens mounts
(Image courtesy: imaging.nikon.com)
If you are a Nikon DSLR camera user, you can get access to DX and FX mounts lenses depending on the camera format you are using.
Nikon FX mount lenses are manufactured to be paired with Nikon full frame DSLR camera, as it features a bigger image sensor which measures 36mm x 24mm. An FX mount lens can also be used on a crop sensor DSLR camera. Being superior in quality, the FX mount lenses usually cost much more as compared to the DX mount lenses.
The focal length mentioned on a lens is actually measured as per the 35mm film format, thus provides the similar angle of view while used on a full frame DSLR camera. But when the same lens is used on a crop sensor body, the angle of view changes (discussed in details below).
Nikon DX mount lenses are especially designed to be used on a crop sensor (APS-C) DSLR camera, sensor size of which measures 24mm x 16mm (slightly larger than the Canon APS-C sensor). Though the Nikon DX mount lenses can also be used on a full frame camera, but the angle of view would be same as that on the crop sensor camera when the crop factor feature is activated.
You can identify an DX lens by looking at the full name of the lens, such as the 'AF-S DX NIKKOR 18-300mm f/3.5-5.6G ED VR'. You can also spot 'DX' printed on the lens.
As we had discussed, the focal length mentioned on a lens (both FX and DX mount) is measured as per the 35mm film format. So when you mount a DX or FX lens on a crop sensor DSLR camera, the angle of view narrows because of the smaller sensor size and gives 1.5x crop factor. Which means that if you are using the 50mm lens on a crop sensor body, you will get the angle of view of 75mm. But when you use a DX lens on a full frame body, you will have to use the camera on 1.5x crop factor mode otherwise you will witness hard vignetting.
To summarize, the FX mount lenses can be used on full frame sensor as well as crop sensor body. But the FX lens will give 1.5x crop factor on a crop sensor body. The DX lenses can also be used on full frame sensor as well as crop sensor body, but it will give hard vignetting on the full frame body as it is not designed to be used on it. Hard vignetting can be avoided by switching the full frame camera into the 1.5x crop factor mode.
(Image courtesy: budgetvideo.com)
Canon offers wide array of lenses for their DSLR cameras which are categorized into: EF-S and EF lens mounts.
EF mount lenses are designed to be used on a full frame Canon DSLR camera. The best part about EF mount lenses are that the same can be used on a Canon crop sensor DSLR camera as well. EF mount lenses have a red dot near the mount and consists of more lens elements, thus costing more than EF-S lenses.
But, when the EF mount lens is used on a crop sensor body, the angle of view gets narrower and the focal length gets multiplied by 1.6x (crop factor). As the Canon APS-C sensor size is a bit smaller than that on a Nikon, the crop factor is 1.6x in Canon APS-C camera body.
EF-S mount lenses are designed to be used on a crop sensor (APS-C) DSLR camera and unlike Nikon, the EF-S mount lens cannot be mounted on a full frame body. If you try to do the, this may damage your camera. The EF-S mount lenses can be identified by the white dot/square marked near the lens mount.
So, in case you are using an EF mount 50mm lens on Canon 600D (crop sensor) body, your camera will multiply the focal length by 1.6x and make it 80mm. If you own a crop sensor body and want to capture sharp and rich colored images, try and invest in EF lenses as they are superior in quality. But if you are looking for budget lenses, then you should definitely go for EF-S lenses.
Sony DSLR lens mounts
A-Mount lenses are designed to be paired with the full frame Sony DSLR camera, which has a 36mm x 24mm sensor. Just like the Nikon FX mount lenses, the A-mount lenses can also be used on a crop sensor camera body, but the focal length will be multiplied by 1.5x crop factor. So if you are using the Sony 50mm f/1.4 Alpha A-Mount Standard Prime Lens, on a crop sensor Sony DSLR camera you will get the angle of view of 75mm.
A-Mount DT lenses are manufactured to be mounted on the crop sensor Sony DSLR cameras. If you wish to use these lenses on a full frame Sony DSLR camera, it would fit on it but would introduce hard vignetting.
Summarizing the above lines, if you want to acquire high-quality optics for your Sony DSLR camera then you should go for A-Mount lenses. But if you are looking for light and pocket-friendly lenses, then invest in A-Mount DT lenses.