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一个变焦镜头在一个焦点段的锐度和十月21日拍的月亮

xia23 2024-10-23 05:56:28 ( reads)

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 softerthis 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 rangemost 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

2. 相片:#690

Shutter Speed: 1/100 s

Aperture: f/8

 

3. 相片:#691

Shutter Speed: 1/100 s

Aperture: f/9

Exposure +0.81 EV

4. 相片:#692

Shutter Speed: 1/100 s

Aperture: f/10

Exposure +0.76 EV

5. 相片:#697

Shutter Speed: 1/50 s

Aperture: f/11

6. 相片:#703

Shutter Speed: 1/30 s

Aperture: f/13

7. 相片:#722

Shutter Speed: 1/20 s

Aperture: f/18

8. 相片:#730

Shutter Speed: 1/8 s

Aperture: f/20

9. 相片:#739

Shutter Speed: 1/8 s

Aperture: f/22

 

10. 相片:#749

Shutter Speed: 1/8 s

Aperture: f/25

11. 相片:#758

Shutter Speed: 1/3 s

Aperture: f/29

12. 相片:#767

Shutter Speed: 1/5 s

Aperture: f/32

 




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跟帖(6)

位酷哥

2024-10-23 06:54:55

真有钻研精神,佩服! 建议所有照片crop成200%-400%,此篇再贴摄坛。

xia23

2024-10-23 11:40:49

谢谢。怎么做?什么是200%-400%的定义?用尺子,用软件,那个软件?再次谢谢。

位酷哥

2024-10-23 15:04:33

中间挖1块就行(放大了才看得清),只要尺寸一样就能比较了

xia23

2024-10-23 13:49:55

你看我用Photoshop elements 2024做的,这是400%吗?98%,398%,没锐化的。#688

JoyAnna.

2024-10-25 05:07:02

人要学会在寻常甚至无趣的时候,寻找生活的乐趣

xia23

2024-10-25 05:52:49

我的兴趣是别人看到又没有仔细看的东西或者仔细看又没有仔细研究的东西。