a long time, the f/0.95 fast f-number for full-frame stopped around 50mm or longer focal length. Until 2021, the lens manufacturer Venus Optics (Laowa) announced the Argus 35mm f/0.95 FF. This is currently the fastest lens with a focal length of 35mm and the widest lens for f/0.95. Professional lenses for some movie cameras have f-numbers as small as . Stanley Kubrick's film Barry Lyndon has scenes shot by candlelight with a NASA/Zeiss 50mm f/0.7, the fastest lens in film history. Beyond the expense, these lenses have limited application due to the correspondingly shallower depth of field – the scene must either be shallow, shot from a distance, or will be significantly defocused, though this may be the desired effect. Zoom lenses typically have a maximum relative aperture (minimum f-number) of to through their range. High-end lenses will have a constant aperture, such as or , which means that the relative aperture will stay the same throughout the zoom range. A more typical consumer zoom will have a variable maximum relative aperture since it is harder and more expensive to keep the maximum relative aperture proportional to the focal length at long focal lengths; to is an example of a common variable aperture range in a consumer zoom lens. By contrast, the minimum aperture does not depend on the focal length – it is limited by how narrowly the aperture closes, not the lens design – and is instead generally chosen based on practicality: very small apertures have lower sharpness due to diffraction, while the added depth of field is not generally useful, and thus there is generally little benefit in using such apertures. Accordingly, DSLR lens typically have minimum aperture of , , or , while large format may go down to , as reflected in the name of Group f/64. Depth of field is a significant concern in macro photography, however, and there one sees smaller apertures. For example, the Canon MP-E 65mm can have effective aperture (due to magnification) as small as . The pinhole optic for Lensbaby creative lenses has an aperture of just . Aperture area The amount of light captured by a lens is proportional to the area of the aperture, equal to: Where the two equivalent forms are related via the f-number N = f / D, with focal length f and aperture diameter D. The focal length value is not required when