In photography many people talk about "fast lenses".. What does this means? Here the definition in Wikipedia:

Lens speed refers to the maximum aperture diameter, or minimum f-number, of a photographic lens. A lens with a larger maximum aperture (that is, a smaller minimum f-number) is called a "fast lens" because it delivers more light intensity (illuminance) to the focal plane, achieving the same exposure with a faster shutter speed. A smaller maximum aperture (larger minimum f-number) is "slow" because it delivers less light intensity and requires a slower shutter speed.

For me there is another aspect of  lens speed: the ability to shoot in low light conditions. And there comes another aspect into the picture: Image Stabilisation. A lens with IS allows you to shoot even at lower speeds. Typically the focal length defines the minimum shutter speed you can shoot without blur... The formula is pretty simple: Minimum shutter speed: 1/f (in seconds).. This means: f=100mm: 1/100 sec. minimum speed.

Image Stabilization offers you typically 4 stops additionally... (Sorry for some calculations now...) What does it means: A lens like the 24mm 1,4L has a minimum speed of 1/24 sec.... But the 35mm lens (which is not an "L"-Lens) offers you 1/4 of 1/35th of a second: theoretical: 4 stops means: not 1/17,5 of a second, not 1/8th of a second, also not 1/4th: it is 1/2 a second... I realized 1/4th... amazing..

Having the lens brand-new I decided to make some test shots... I looked for shooting with open aperture and with lowest ISO possible...

Advent Time decoration

In the forest... the narrow depth of field and a contrastful image...

Just a tree? Bokeh! Nice, or?

Just a Vespa in the forrest...