一个变焦镜头在一个焦点段的锐度和十月21日拍的月亮

先得谢谢位酷哥，位酷哥让我找的我的镜头的锐度，没他的帮助是不可能有这篇文章的。我愿意加他为作者。

什么是锐度：

Google的AI回答：

"Sharpness of a lens" refers to the ability of a camera lens to capture fine details in an image, meaning how crisp and clear the subject appears, with a sharp lens producing distinct edges and textures, while a less sharp lens might result in blurry or soft details; it's essentially a measure of the lens' resolution and is often judged by how well it can render fine lines and patterns across the entire image frame, from the center to the corners.

For most lenses, sharpness in P-Mpix is typically between 50% and 100% of the sensor pixel count, and differences smaller than 1 P-MPix are usually not noticeable. The best resolutions are usually achieved by prime lenses at apertures between f/2.8 and f/8.

变焦镜头的锐度在不同的焦段是不同的：

Google的AI回答：

In a zoom lens, sharpness typically varies across the zoom range, with the best sharpness usually found in the middle of the zoom range, while the extreme wide and telephoto ends tend to be slightly softer; this means a zoom lens is often not as sharp at its maximum zoom as it is at a middle focal length, and is generally considered less sharp than a prime lens with a fixed focal length due to its complex internal mechanics.

For a zoom lens, the aperture at which you find the best sharpness at a specific zoom range is usually not fixed across the entire zoom range; most zoom lenses have a variable aperture, meaning the maximum aperture changes as you zoom in or out, so you may need to adjust your aperture depending on the focal length you're using.

位酷哥建议我用ISO12233去查锐度。

我刚刚从aliexpress order了一个：

位酷哥建议在没有锐度表的情况下可以用不同的aperture拍照片试一下。我用50-500mm变焦镜头在500 mm的焦段从f/6.3到f/32拍了12张照片，找到f/9是最清晰的光圈 (第三张相片）.

注意这只是在500mm焦段的最佳锐度，其它的焦段，例如50mm,我还没有试。到用时再试，最简单的事情是来了锐度表再试。

以下是硬件和软件：

Camera: Nikon D300s

镜头：Sigma 50-500 mm

三脚架：Manfrotto 501HDV

Size: 3216x2136 pixels

ISO：200

Mode: M

Focal length： 500 mm

Sharpen: by Corel AfterShot pro 3.0

以下是 12张照片，10/21/2024 9:45:31 pm 开始第一张, 9:56:21 pm结束最后一张。

查看第2，3，4和5张相片里的红圈，我看是第3张，f/9最清晰。你们同意吗？

1. 相片：#688

Shutter Speed: 1/100 s

Aperture: f/6.3