Connections and equipment

As the most important function, the bayonet must secure a lens safely to the camera. To change the lens, however, this connection should also be released quickly and easily on the other side. For this purpose bayonet connections have been established since the 1970s and the older screw connections have been replaced. The lens is inserted into the housing and fixed by turning. After detaching the lock and turning it in the opposite direction, the lens can be removed.


Connections – what should you pay attention to?


Lesetipp: How modern lenses work


Features of lenses


Unfortunately, you can not operate any lens available on the market with any camera. For the bayonet and the control contacts, the camera makers cook their own soup. As a result, you must ensure that it is compatible with your own housing when selecting the lens. The most common connections of SLRs are EF- and EF-S bayonet (Canon), F-bayonet (Nikon), K-bayonet (Pentax), A bayonet (Sony) and Micro Four Thirds (Olympus, Panasonic). The largest selection of lenses is available for market leaders Canon and Nikon. But for other cameras as well, there is a satisfactory to good range of powerful lenses.


What are the advantages of light-weight lenses?


There are also a number of manufacturers who produce lenses with different bayonet connections and which are often a more favorable alternative to the lenses of the camera manufacturer. Sigma and Tamron are the largest of these foreign manufacturers, others are Tokina, Zeiss, Walimex and Schneider Kreuznach. And as the ColorFoto lens tests show, these lenses can capture the images well with the originals.


Old lenses on modern cameras


The price range for lenses is great. A lens with very simple equipment is already for under 200 euros to have, a light-strong telephoto lens for professionals can, however, already approach the 10,000 euro mark or significantly exceed it. For example, the Sigma 2,8 / 200-500 mm costs almost 24,000 Euro as much as a brand-new VW Golf. The most important question is therefore always: What is the objective of the lens? In addition to light intensity and focal length, there are other distinctive features.


An autofocus motor is almost always a feature, but as an ultrasonic motor it operates faster and quieter. Especially when it comes to speed, as with sports and animal photography, such an optics can score points. The so-called Steppermotoren - small stepping motors, which are also fast and quiet and work better with the contrast auto-focus measurement of the mirrorless models

Despite the excellent autofocus, some photographers prefer to sharpen by hand - even if there are no logical arguments for this. In this case, it is important that the focus ring on the lens is handy, easy to move and does not have too much play.


An integrated image stabilizer allows shake-free recording even in poorer light conditions. If the camera itself has an image stabilizer, it is dispensable in the lenses, otherwise, especially with long focal lengths a must. Lens elements which are particularly shaped (so-called aspherical lenses) can help to avoid image defects. In addition, there is a complex coating that suppresses reflections without swallowing light (compensation).


The mechanical value should be an issue especially when a lens is frequently used. A bayonet made of metal not only fits better and rests more beautifully than one from plastic - it also has less abrasion and is therefore more durable. A very not insignificant criterion when buying a lens is also the close-setting limit - the shortest distance, where a subject is still sharp. A low focusing distance can significantly extend the photographic possibilities. Macro lenses are specifically designed to capture images that are close to the lens.


To make it clear again: even high-quality lenses are not free from imaging errors - the errors are only much smaller. And whether the lenses come from the manufacturer of the camera or a foreign manufacturer such as Sigma or Tamron, Zeiss or Tokina, genausowenig plays a role. Foreign producers often have special focal lengths (especially zooms) on offer that you can not find in the opulent assortments of Canon or Nikon in vain, and can often offer their products even more favorably by producing larger series with the most diverse connections. There is no general difference in quality in any case. Here, too, the ColorFoto lens database is available to you in the individual case - which makes every manufacturer equally objective.


One way to work with low light without flash is to increase the ISO number, but the picture noise increases. The only alternative is a light-fast lens. This allows you to shoot good pictures even in relatively dark rooms. Many normal zoom lenses have a light intensity of 1: 4, but a light-stable normal lens with a fixed focal length of 50 mm has a light intensity of 1: 1.4. Since the light quantity per doubling of the aperture is always doubled, then eight times as much light reaches the sensor when the aperture is open.


Light-weight lenses have almost only advantages, but the most important drawback quickly becomes the KO criterion: they are expensive. Even a 50-millimeter lens with light intensity 1.4 with 300 euros costs about twice as much as a lens with light intensity 1.8. And in the telephoto it is really expensive, if one for animal or sport recording high light intensities is needed. For a 300 telephoto with a light intensity of f / 2.8 one often pays more than 4,000 euros, for a 500 tele with f / 4.0 usually more than 8,000 euros. In the case of long focal lengths, light-weight objectives are also significantly larger and heavier than those with low luminous intensity


For many high-speed lenses, the image quality in the corners is not optimal when the shutter is photographed. Fading significantly improves the quality. In practice, it has proven useful to close the diaphragm by one step as far as possible. As less light-emitted lenses have to deal with similar problems at the initial opening, the advantage of the light intensity is maintained.


Lesetipp


As a rule, more light is incident on the AF sensor by means of light-stable objectives, which benefits the autofocus speed. And, of course, light-weight lenses offer the photographer more creative freedom, such as working with selective sharpness.


Lesetipp: This is how modern AF drives work


It is often a characteristic of high-quality zoom lenses, if the light intensity remains the same over the entire focal range. For more favorable models, it decreases with increasing focal length.


Lab tests always confirm that a lens achieves its best performance as soon as it is dimmed by about two levels. Although an aperture with a continuous aperture of 1: 2.8 can be used without hesitation even with an aperture being open, the imaging performance reaches peak values ​​at about aperture 5.6.


If you have old lenses, you can usually use them on a digital SLR camera from the same company. Anyone who owns a larger lens palette will have to pay attention to this compatibility when choosing a new housing. On the other hand, there is no reason to object, but you should be aware of the limitations.


If the new housing is accompanied by a format change (for example, from the analog image to the APS-C format), the crop factor must be considered. Missing contacts to control the lens often restrict the automatic functions, so that you often have to adjust all settings manually with older lenses. This also applies to shooting. If an old lens does not have an autofocus or if it is not controlled by the camera, you have to focus manually.


Also another problem of old optics should not be underestimated. Since it was irrelevant in the film at which angle a light beam hits the silver halide crystals, light beams here often do not strike the film plane perpendicularly. Today, however, there is a sensor, the pixel of which is the best light when it hits the right angle. This effect provides a slightly inferior imaging performance of a lens in the digital setting. Last but not least, the old lenses were expected for film, their resolution is just too bad for modern sensors.


So to put it clear: To a modern DSLR belongs a suitable lens and not an oldie. This should at least be considered for the focal lengths, with which one works most frequently. Pleasant side effect: modern optics are often smaller and lighter thanks to improved materials and designs. Special objectives such as microfotography or some supertele have always been connected via adapters. Such optics can usually also be used on the new DSLR.


In order to get a picture of the differences, it is often worth taking a walk to the retailer. Take your old lens and ask him to take a few shots with this old lens and a current lens in the shop. Look at the pictures at home in silence at 100% display size on the monitor. If you do not see any big differences, it is good - but the differences will probably be clear. Then look at an overall view of the respective pictures, because this is the only way to recognize the edge dimples of the lens. Usually, you make all the test recordings from the tripod with remote trigger, which prevents jiggers.