.

Lens Focal Length & F-Stop Focal Length and F Stop are basic indicators of lens performance Focal Length affects magnification and angle of view, while F-stop affects brightness While a wide variety of lenses are available, they are broadly grouped by focal length and F-stop. Lenses with short focal lengths will have a wide angle of view, while longer focal length lenses will have stronger magnification, creating what is called a telephoto lens. The F-stop value shows how bright the lens is, i.e., how much light will pass through it when the aperture is opened to its maximum. The smaller the aperture value, the brighter the lens. A brighter lens gives a photographer more freedom in a variety of situations. What is Focal Length? Focal length is the distance from the center of the lens to the imaging point (focal plane) where the light for the image is collected. When a lens is described as a "50mm lens," it is referring to its focal length. Different foc...

The pound hasn't been this strong against the euro since 2008. Is this as good as it gets? We ask leading thinkers in the world of finance Skiers and owners of holiday homes in Europe want to know what the future holds for the euro exchange rate   By  Richard Evans 05 Dec 2015 As thoughts turn to skiing trips or visits to holiday homes in Europe or further afield, it’s time to ask whether now is the best time to buy foreign currency. In recent years the foreign exchange markets have been very volatile, with the pound appreciating dramatically against the euro but losing some of its value against the dollar. These moves are being driven by strong forces at work in the global economy. The key global trading blocs are all at different stages of their recovery from the financial crisis. As a result, they have different plans for interest rates, and other tools of economic control such as “quantitative easing”, also known as QE or s...