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How to Choose the Function of a Light-Shielding Ring

Release Date:

2020-07-27 11:43

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How to Choose the Function of a Light-Shielding Ring

　　A lens hood, as the name suggests, is a device used to block stray light. There are many types of lens hoods, but the most common ones are flower‑shaped, cylindrical, and square. Many beginners purchasing kit lenses don’t get a lens hood—likely because entry‑level kits emphasize affordability, and adding a hood would significantly increase the cost.

　　How do you choose the function of a lens hood?

　　1. Lens hoods are also among the most frequently purchased accessories. They help minimize stray light that can degrade image quality during shooting. Nowadays, most telephoto compact digital cameras come with a lens hood as standard, whereas owners of manual‑focus point-and-shoot cameras may not enjoy this benefit.

　　2. When purchasing a lens hood, it’s best to bring your DSLR along, as some excessively long hoods can produce four distinct vignetting effects when the lens is used at its widest angle.

　　3. Therefore, DCs with wide-angle lenses are best equipped with petal‑style lens hoods, while other DCs can use ring‑type hoods; there are also foldable soft‑rubber hoods that allow you to adjust the hood’s length to strike a balance between the two.

　　4. Lens hoods come in various sizes; you should choose one that matches your lens’s focal length. The shorter the focal length, the wider the angle of view, and the shorter the hood will be. For example, if you attach a standard‑focal‑length lens hood to a wide‑angle lens, it will inevitably result in vignetting—areas around the edges of the frame will fail to capture an image.

　　5. Conversely, it will fail to provide the intended shading effect. When using a zoom lens, it is best to equip it with a retractable lens hood that can be extended as needed.

　　6. Lens hoods are widely used in backlit photography and generally help prevent flare. However, if the light source is close, flare may still occur.

　　7. At this point, you can use your hand to partially block the lens hood on the side where the light source is located. Whether the flare has been eliminated should be carefully checked through the viewfinder.

Four things to keep in mind when using a lens hood.

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