Companion Suitable for General Use:
OM System M.Zuiko 12-40 mm f/2.8 II Pro

The smaller and more compact structure of mirrorless cameras compared to DSLR bodies allows them to be carried easily both in daily use and during travels, and thanks to the fact that they are produced with the latest technology, they can also be used successfully in many photography subjects.

The OM System 12-40 mm f/2.8 II Pro lens, announced with the OM System OM-1 model, is one of the best alternatives for general photography and especially in low light conditions. Thanks to the Micro Four Thirds system with a 2x optical multiplier, this lens sees from the angle of view of a 24-80 mm lens and is a smaller, lighter and more economical alternative to the 24-70 mm professional lenses available from many brands. Thanks to its water and dust proof feature, it also gives the opportunity to use it in all conditions with the OM-5 and other MFT bodies.

In laboratory tests, shots were taken at 12 mm and 40 mm at 2.8 apertures. In these tests, no problems were encountered in corner sharpness, and it was observed that there were no problems in both center and edge-corner sharpness in the shots taken at 4, 5.6 and 22 apertures. However, I always think that our daily uses are more important than laboratory tests. Therefore, when I examine the shots I took in different lighting conditions and on different subjects, I can see that there is a high quality of sharpness at almost every aperture value. I can say that I have had very successful results in previous photo album and exhibition prints.

Chromatic Aberration
Again, in laboratory tests, very small (0.003%) chromatic aberrations were observed at different aperture values in shots taken at 12 mm - 30 mm and 40 mm, but this is not important in any photographic work. We do not feel the bad effects of such deviation in our daily use. Vignet
It can be seen that at values wider than 5.6 aperture, there is less than half a stop of darkening in the corners. When the aperture goes above 5.6, these darkenings are not encountered.

No noticeable deformation was observed in the shots taken at different focal lengths. When the lens was used at 12 mm, "barrel distortion" of 0.25% was observed, but when it was increased to 14 mm, this distortion disappeared. If it is 25 mm and above, there is no deformation.

Autofocus (AF)
The M.Zuiko 12-40 mm f/2.8 II Pro lens has a very fast autofocus system. Sharpness changes from the closest sharpness distance to infinity in less than a second. Thanks to the silent AF system, smooth operation can be achieved in video shooting. Since the front elements of the lens do not move when the AF system works, accessories such as Circular Polarizing Filter can be easily used with this lens. Pulling back the front ring on the lens switches the lens to MANUAL focus system. When you push the same ring forward, the AF system is activated. This change you will make is also shown in the FOCUS section on the INFO screen.

Macro Shot
This lens is not produced for macro shooting, but its close focus distance of 20 cm helps to take very detailed photos.

Physical Properties
The M.Zuiko 12-40 mm f/2.8 II Pro lens has an all-metal structure. Thanks to the rubber seals inside, it is water and dust proof. Weighing 380 grams, the lens is almost half the weight of its counterparts on full-frame cameras. Lens diameter is 62 mm. There are 14 lenses in 9 groups within the lens. The diaphragm consists of 7 parts and operates at values between 2.8-22. The L-Fn button (Lens Function) on the lens is a button that can function in the camera menu. Thus, by assigning a feature you use frequently to this button, you will have the chance to use it without entering the menu.
Especially when compared to 24-70 mm lenses used in full-frame cameras, the OM System Zuiko 12-40 mm f/2.8 Pro lens stands out with its solid structure, small and light body, open aperture value, sharpness ability, chromatic aberration and minimal corner darkening. Additionally, its water and dust proof feature is an added advantage. This lens, which can be easily used in general photography, gives very good results in almost all light conditions with its 2.8 aperture.