[bfsiu]

Is there any A 快門 ? What is the difference between the two ?

[wtfgary]

B 快門 - for you to keep the shutter open. Take 300D for example, I used B 快門 it to take some photos of stars, so I pressed and hold the shutter button, then the shutter kept open for 150 seconds or so ...

[b_kid]

係咪有人用B 快門開啟 shutter 來 clean DSLR CMOS/ CCD?

[philip5cf]

wftgary，點解唔用搖控呢？又唔貴！好方便！

[wtfgary]

philip5cf, yes, actually I was using *"shutter cable control" to hold the B 快門 that time.

* Sorry, not sure about the correct term in english.
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"係咪有人用B 快門開啟 shutter 來 clean DSLR CMOS/ CCD? "
Actually is no need, cause there is a build-in function for this.

[b_kid]

有些時侯唔適合用 remote，如影煙花、閃電，用 remote 會捕捉唔切，有錯請糾正 ^_^"

[embu31]

"B" stands for "bulb". This setting lets you to control how long the shutter opens. It is used when the light is very dim or for night shots when you use smaller aperture for maximum depth of field and the camera cannot properly calculate the time it takes to give the effect you want. At this setting, you will mount your camera on a tripod and use wired shutter cable to control the shutter release.

IMO, when you're experienced in shooting fireworks or lightning, you will point your camera at the right angle, open the shutter at any time you want and hope for the best. By the time you "see" the lightning, you will never be fast enough to press the shutter release and capture the picture!

BTW, you can use the remote control (e.g. Canon RC-1) to release the shutter. First time your press the button, the shutter opens. Second time you press the button, the shutter closes. Remember to use rc and mirror lockup to minimise camera shake.

Don't try to use "blub" for cleaning the CMOS/CCD, because if you accidentally hit the shutter release or the power goes out, your cleaner will damage the shutter curtain! Use "CMOS/CCD clean" setting to manually override the shutter release to prevent any accident!

[philip5cf]

b kid, 有線果隻 remote 係同你按快門一樣反應暨！有錯請指正！謝謝。