All zooms change the size of the virtual or effective aperture while zooming, "constant aperture" (really constant f-ratio) simply change the aperture enough to keep the aperture to focal length ratio the same.

Nov 10, 2022 · A fixed aperture lens is sometimes referred to as a constant aperture lens. This means the aperture of the lens does not change depending on the focal length. Being able to change the aperture regardless of the focal length means that the photographer has much greater control over the photo.

Jul 19, 2024 · A fixed aperture lens, also known as a constant aperture lens, maintains the same maximum aperture across its entire zoom range. Whether you’re zoomed in or out, the aperture stays consistent. Consistent Aperture: The lens maintains the same maximum aperture regardless of the focal length.

It’s a constant or what is also known as a fixed aperture lens. How can you tell? It states it is an f/2.8 lens – it’s a single number. A variable aperture lens would be the Nikon 18-200mm f/3.5-f/5.6 lens where two f-stops are listed on the lens. Now what does all that mean?

Sep 15, 2014 · A constant aperture lens must only zoom in front of the aperture stop. To a certain point moving the elements in front of the stop further and further away will increase the focal length of the lens. Bringing them closer to the stop decreases the focal length.

Jun 4, 2021 · With a fixed aperture lens, the aperture functions independently from the focal length of the lens. Meaning, whether you’re zooming in or not, your aperture stays constant until you adjust it either within your camera.

Mar 5, 2010 · With a variable aperture lens, unless you set the aperture beforehand at f5.6 - when you zoom out again, the aperture will recalculate and change the exposure. Variable aperture lens is still perfectly fine if you plan on using a stop smaller than the maximum at the high range (i.e. 5.6 on a f4.5-5.6 lens).

Mar 20, 2018 · Constant aperture is even more important for video. If you are doing a zoom from 28mm to 100mm the aperture will change from F2.4 to F4. And it won’t be smooth.

A constant aperture lens maintains the same aperture throughout its zoom range, meaning that regardless of the focal length you set, the aperture remains the same. For example, an f/2.8 lens will have a maximum aperture of f/2.8 throughout its entire zoom range.

Nov 11, 2008 · The constant aperture zoom lens is desirable for hand-held photography because shutter speed must decrease in proportion to focal length for a given image composition (so the image shifts less than one pixel during the exposure). In fact, it would be better if f-stop INCREASED with focal length.