How can I find the most suitable lens for my DSLR?
A good lens is vital if the photo is to turn out well. The lens also determines the look and quality of the photos. It is a light-gathering optical system for the camera that produces an exact copy of a motif. When it comes to selecting the most suitable lens, there are two prime criteria of importance in addition to the actual purpose that should be taken into consideration when purchasing: focal length and aperture.
Grit Hiersemann (Professional Photographer Jena/Germany) recommends: “When purchasing a single-lens reflex camera, attention should be paid to which brand is chosen. While the majority of the technology is integrated more in the camera housing in the case of Nikon, in Canon cameras the same type of technology is contained in the lens. Attention also needs to be paid to the fact that not every lens fits onto every camera; certain connections are brand-specific.”
Two primary criteria when it comes to choosing the most suitable lens
With the help of the aperture, with which the range of the lens is regulated, the amount of light that should be allowed to go through the opening in the lens is determined.
The ratio of focal length to the width of the aperture opening is described as the exposure time, which is labelled either 1/x or f/x. The larger the number x under the fraction line when calculating the exposure, the less light passes through the aperture to the sensor. This is often called shooting with a closed aperture. If the value of x under the fraction line is smaller, then the exposure time is longer. In this case, the aperture is more open so that more light can hit the camera’s sensor.
Another term that’s often used instead of exposure time is “f-number”. The f-number is the individual value “x” without the fraction. If the term f-number is being used, the previously mentioned rules are reversed. A large f-number translates to shooting with a closed aperture and a small f-number means shooting with an open aperture.
The aperture doesn’t only regulate the amount of light that hits the camera sensor, but also the amount of space that appears sharp in the photo. When using a longer exposure time, such as f/1.8, the amount of area depicted sharply is smaller and there will be a lot of blurriness in the background. If the photo should appear uniformly sharp, then a shorter exposure time such as f/16 is necessary.
When you compare the maximum opening of the lens with the focal length, you end up with the lens speed, which is a sign of the quality of the lens.
Five types of camera lenses
A macro lens for successful close-up photographs
If the photographer would like to photograph food, flowers, small animals or insects, a macro lens is most suitable. With a magnification of 1:2 or 1:1, fascinating close-up photographs are possible. Even though such macro lenses are comparatively a little heavier, such lenses are recommendable for nature photographers. It is ultimately the case that those who photograph with a macro lens find it difficult to go back to not using one.
For those who seldom have to do with macro photography, it doesn’t make any sense for them to invest in expensive extra lenses because with a close-up lens, a reversal ring or an extension tube, standard lenses can be tuned in order to take macro photographs.
Grit Hiersemann recommends: “If you want to save a little bit of money, but still want to photograph an ant or a bee on a flower, you don’t have to spend a lot of money on a macro lens. You can buy extension tubes instead. You can buy a set of three for a relatively low price when compared to the effect achieved. You screw these between your existing lenses and the camera and this creates the exact same effect as with a macro lens.”
A standard lens is the optimum for those getting started because it has all the important focal lengths for the majority of purposes. The majority have an aperture that can be smoothly set using the aperture ring and focus ring making diverse sharpness set-ups possible. Whether photographs of nature or holiday photos, a standard lens can usually be flexibly utilised when a long focal length of 35-55 mm and converging lens are used in conjunction with the input from the sensors. The lens can be safely stored and taken everywhere and can be quickly taken out at the right moment.
- Focal length: 18-55 mm
- Suitable for: Daily situations, nature photography, travel photography
Pros: These lenses are easy to transport, are suitable for just about any motif, and offer very flexible set-up possibilities.
Con: Taking close-up shots from a further distance is not possible.
Portrait lens with a fixed focal length
Portrait lenses in most cases have a set focal length that excludes a distortion of the image, which is actually an advantage with other lenses, but it is not wanted here. Due to the fixed focal length, the image section can only be altered by adjusting the distance between the lens and the motif. The sharp area of the image is also regulated by the opening of the aperture. Due to their design, lenses with a fixed focal length typically have the advantage of larger f-numbers, which makes them faster lenses.
Such a lens is also usually cheaper, faster, and produces particularly sharp photographs. This means, for instance, that for a camera with a crop factor of 1.5 or 1.6, a 50 mm lens can be used as an “all-rounder” because it does not contain a photograph-specific distortion. Fixed focal length lenses of 80-85 mm are also popular in portrait photography. A fixed focal length of 70-105 mm is recommended for full-format cameras.
- Focal length: Between 50 and 105 mm
- Suitable for: Portrait photography
Pro: Photos are more brilliant and sharp.
Con: Very little flexibility in their use due to no zoom function.
The longer the focal length of a lens is, the larger the possible magnification of the object to be photographed. This is the exact purpose of a telephoto lens. Thanks to its high focal length and the limited depth of field, far-away objects, for example at sports events or in nature, can be photographed in good quality. This allows precisely defined photograph sections and a high image quality to be achieved even from a far distance.
- Focal length: 150 - 1300 mm
- Depth of field: Limited depth of field
- Suitable for: Sports photography, concert photography, nature photography, travel photography
Tip: A tripod or stand can be used to keep the image section still and will produce a sharp result.
Pro: Overcomes distances excellently to the motif to be photographed.
Con: Relatively cumbersome and heavy due to their size.
One last tip from Grit Hiersemann: “What I would recommend would be: definitely buy yourselves a bag for the camera. Time and time again I see people on the beach with the camera around their necks and not even a cover on the front of the lens and everyone can see the camera. The camera needs to be packed in the bag; the sensor can otherwise quickly become dirty and it is really expensive to have the sensor cleaned. You can save yourself this hassle by being careful with your equipment.”