[moliuguy]

58mm 遮光罩大約幾銀?
thank you.

[tam_dominic]

It is to avoid bright light other than the main subbject goes into the CCD.

When strong light goes into CCD/film the photo will be foggy and not clear.

Some 'big C' even use an umbrella to shade the whole camera for this reason.

[hkhei]

另一個主要用途係保護鏡頭....

[dclkwok]

The main function is to avoid the sunlight comes in front (behind the main object) of the camera which will directly project onto the lens and hence the picture become "foggy" and not clear. You may put your hand on top of the lens if you don't have a 遮光罩. Um... the 遮光罩 can protect the lens in some way but not the main function.

[hkhei]

對我黎講，遮光罩保護鏡頭o既功用，比擋入光o既功能更重要
如果支鏡頭設計得好，光斑o既情況唔會太嚴重

就正如uv filter一樣...保護鏡頭都係佢o既主要功能