Lens Speed or how fast a lens is actually closely related to the maximum aperture is owned by the lens. Aperture is the size of the lens opening when the shutter button is pressed (or how much light enters the camera). Aperture is denoted by F (f-stop).
The smaller number makes wider aperture, and there will be more light coming in at one time. This means the shutter speed becomes faster. Lens speed should you know due to:
- Lens "fast" with a maximum aperture of f/1.4 allows you to shoot in relatively dark place better than the lens has a maximum aperture of f / 4 or f/5.6, but that does not mean a slower lens is not good.
- The "fast" lens allows you to retrieve the moving object without getting motion blur.
- Lens "fast" allows you to get the depth of field of thinner / narrower. This means that when you focus on a subject in the foreground the background will be blurry or out of focus. Having a lens 'fast' of course means it is possible to get focusing a little more 'tricky', given the depth of field is used very thin / narrow. For example, when photographing portrait of a face with f/1.4 aperture and focus on the eyes, then most likely you will find the nose a little out of focus.
- The 'fast' lens is usually more expensive than a slower lens.
- The faster lenses would be helpful in terms of flash photography in recording or taking ambient light.
- Lens speed aperture lens with f / 4 is usually good for general purpose photography with good lighting conditions
- f/5.6 requires good lighting or features image stabilization (IS / VR)
- If you shoot indoor without flash, then at least use a lens with f/2.8, and
- If you are shooting indoor sports then at least use f/2.0 or 'faster'.
Focal length is length of the lens. This measurement is the distance between the middle of the optical lens to the focal point on the camera sensor. What you should know is that the focal length of a lens inform you when photographing subjects how much will be enlarged. Focal Length also inform the angle of view.
This is the measurement between the end of the lens with the closest point of object. This is useful when shooting in macro or close-up photography, because this type of photography requires a very close distance of the object to end of the lens.
This feature is useful for minimizing vibration or shaking the camera (Camera Shake). Most DSLR lenses is now equipped with image stabilization (the Canon lens known as IS, and the Nikon lens is known as VR).
Camera Shake is a movement that occurs when the shutter is opened. This incident had a greater impact on the photos when we use slow speed, no tripod, and when use a lens with a longer focal length.
Image Stabilization helps photographers reduce camera shake at low light levels, but it does not freeze the moving subject. Basically IS allows us to take photos at lower shutter speed which the camera aperture open a little longer.
IS features mean additional cost on a lens, so you need a consideration of whether the activity of shooting with lenses that require this feature or not. Example: Do you frequently shoot in low light conditions using a long focal length without a tripod?
Considerations in buying lenses when going to upgrade is the cost. Most people agree that "we get what we pay", and we prefer to upgrade the lens than replace the camera body (depending on conditions). A little wary of the 'kit lens', in many circumstances these lenses are good, but we think it would be better if we buy only the camera body and then choose a better lens than the kit.
There are so many opinions say that to produce great photos should use a lens with the same brand with the camera compared to using cheaper third party lenses. In our opinion, for the first time try to find the same brand lens with the camera body, if you can not find try to find the lens of a third party. The fact is that every lens manufacturer has produced good and less good lenses that have been circulating in the market. Do your research before buying a lens through websites and forums that provide a review and comparison.
To be continued...here