HELP! noob with a question!


TPF Noob!
Jan 26, 2007
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A.C.T Australia
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i own a 40d and i simply like to know how you do really long exposures, like 10 minutes long?
do you have to merge a heap of 30 second exposures or can you actually have the shutter open for 10mins or longer?
ive googled it and nothing concerning my question came up.

any help is greatly appreciated
Yes, the 40D has a bulb mode.

You'll need to be in manual mode, manually set the shutter speed to bulb.
I own the D90 and this, too has a bulb mode. I dont mean to jack the thread or anything, but Id like to know what this does. How to use it and what its function is.

what, so i have to just hold down the shutter for 10 minutes?
isnt there a better way?
Mark, bulb is for long exposures.

The shutter will stay open as long as you hold down the shutter button. You can also use a remote shutter release which allows you to hold the shutter open without touching the camera(doing so would probably cause shake and blur your image).

The one use for bulb that I'm aware of is photographing star trails at night. I'm sure there are others but I'm not aware of them.

As far as locking the shutter open, I don't know. I don't think my D60 has that feature, you just have to hold the shutter button down(on camera or the remote) for as long as you want the shutter to stay open. Not sure about the D90 or the 40D.
Most remote shutter controls have a lock position so you can press the shutter release on the remote and push it forward and it will lock the shutter open.

A couple of notes. If you do long exposures like this, your sensor will heat up, so be careful about doing multiple long exposes. Also, long exposures will introduce a lot of noise into your image.
The Bulb shutter speed is used to open the shutter for as long as the shutter release is held closed.

You can hold the shutter button on the camera for the duration ... though this may cause camera shake if you are not careful.

Most users will get a cable shutter release.
Canon has the RS-80N3 remote switch ... I think it has a lock switch so you do not have to manually hold the button down for long exposures.
I'm surprised that you had to google that..;)

My camera came with a book and tells all about "Bulb Exposures". Your camera will also give you a countdown in the display for how long the shutter is open for (1-999 seconds), and a recommendation on the remote release...

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