Bulb setting on 400D

Started Aug 14, 2007 | Discussions
noahk New Member • Posts: 2
Bulb setting on 400D

Hi all,

I was just wondering if there was a way to keep the shutter open in bulb setting on the 400D without having to keep my finger on the shutter button, and without using a remote. I would buy a remote but I'm in an isolated location for the next 3 weeks so I can't, yet I want to take photos of the sky!


balloonchasers Veteran Member • Posts: 3,189
Re: Bulb setting on 400D

Short answer.. No.

Depending upon how "isolated an area" there is the option of making your own:

Do a google search for (DIY, 350XT remote) and you will find some ideas such as this one:


Hope this helps.


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Feel free to use any of these additional letters to correct the spelling of words found in the above post: a-e-t-n-d-i-o-s-m-l-u-y-h-c

Bytec Forum Member • Posts: 69
Re: Bulb setting on 400D

No, you have to keep shutter button pressed.

sez Forum Member • Posts: 54
Re: Bulb setting on 400D

As far as I know you need the remote to keep the shutter open. Actually you might use a strong enough rubber band around the grip with something like a piece of cork between the band and the shutter release button. Theoretically the band might create the pressure for the cork to press on the shutter release. But I would'n do that, and I thing you wouldn't do it either - it could press too much and damage the button. And if you want a remote and can't get it right now check out my home made very cheap alternative. You may have the parts needed.

I emptied the inner parts of a 9V battery and installed the switch inside. Works flawlessly

It should fit the 400D right?

OP noahk New Member • Posts: 2
Re: Bulb setting on 400D

thanks for the answers- I'm at an observatory in Chile in the middle of the desert which is why it's difficult for me to get the remote. I'll look into this DIY remote though, thanks! otherwise I may give a try to the cork and rubber band alternative

rayfound Forum Member • Posts: 84
Get a remote $10

Get a $10 RC-1 Remote on ebay. Press once to open. Press again to close - Perfect.

Colin Peart Regular Member • Posts: 193
Re: Bulb setting on 400D

You haven't got the circuit quite right, though it will work on manual, and with manual focus just fine.

The actual remote would keep the AF circuit closed while closing the shutter switch -- that would prevent the AF from causing camera shake. When you close just the shutter circuit, the camera does try and activate the AF breifly before closing the shutter (unless you have it on MF, or if the AF is locked.)

Besides, for doing shots at the observatory, you might want to activate mirror lockup which needs a momentary contact on both circuits to activate. So, try this:

Connector (2.5mm mini stereo plug):

Tip Common
~ ~
o~== ===[======]

Tip connected to common = shutter
ring connected to common = AF

T(Shutter) ------(switch)---------~

The common line switch is normally in the closed (on) position.

When you want to take a long exposure photo, without mirror lockup,

first you activate the AF line, and when the camera is settled, activate the shutter line. Open (turn off) the shutter line to close the shutter.

If you activate mirror lockup in the custom functions menu, then you first activate the AF line, then the shutter line. This will lock the mirror up. Now, turn off the common line switch to ready the camera for the exposure. Turn it back on to release the shutter. You might want to use a NC push button instead of a switch on the common line, because it only takes a moment to lock the mirror up and settle before the exposure, however, an NC (normally closed) pushbutton may be hard to find -- most are NO (normally open).

The only other option you might like is an NO pushbutton in parrallel with the switch for the shutter. This will allow you to easily take a single exposure when the exposure time is something the camera can handle by itself.

P.S. No warranty on this... I based this on the various other sites on home made camera remotes, and my own experiments. If you break the camera, it's your problem, not mine. As a programmer, we sometimes say #include

rayfound Forum Member • Posts: 84
Re: Get a remote $10

Sorry - I missed the part about not having access to get one... but really, when you get home, the little IR remotes are nice.

Michel Pyck Contributing Member • Posts: 913
Re: Bulb setting on 400D

it is in manual mode
just dial to the left so your speed decreases intil it reaches 1", 2" ,.... BULB

when you press the shutter to take the picture keep holding it down as long as you want; you will see the time of exposure on the lcd panel

 Michel Pyck's gear list:Michel Pyck's gear list
Canon EOS 400D Canon EOS 7D Canon EOS 70D Canon EOS 7D Mark II Canon EF-S 10-22mm F3.5-4.5 USM +6 more
sez Forum Member • Posts: 54
Re: Bulb setting on 400D

Yes you are right, the camera does want to focus just before shutter. Actually it has never caused bad photos, but since you mentioned it I think I found the workaround - just activate the mirror lock up in Custom functions menu. In that case you press the switch for shutter once - it locks the mirror, AF and exposure. Then you release and press again - the photo is taken. My version is just a simple solution and works for me, still I would love to see your diagram with clearer explanation as well. (I didn't quite understand the ASCII diagram, sorry :))

Colin Peart Regular Member • Posts: 193
Re: Bulb setting on 400D

Is this diagram more clear:

In case the text is too small to read:

To Activate the AF circuit: Flip the AF switch on.

To take an extended exposure without mirror lockup: first activate the AF circuit, then use either the shutter switch (hands free) or the shutter button (hold it) for the exposure.

To take an extended exposure with mirror lockup on:

First activate the AF, then activate the shutter switch. This will engage the mirror lockup. Next, push the mirror lockup trigger down and release it to open the shutter. Turn off the shutter switch to end the exposure.

The mirror lockup trigger is a push button that normally keeps the circuit connected, unless you push it. When you push it, it disconnects the circuit.

The reason for the switch on the common portion is that mirror lockup requires the AF and shutter circuits to be both opened and closed again to take the picture. That last button will simultaneously release both circuits, and when you release the button, activate them both again.

sez Forum Member • Posts: 54
Re: Bulb setting on 400D

That's great, thanks very much!!

Colin Peart Regular Member • Posts: 193
Re: Bulb setting on 400D

I just wanted to add a note -- I noticed while playing with the bulb setting that to close the shutter, both the AF and Shutter circuits need to be released -- that NC button on the common line might be a better choice if you need to cut the shutter quickly -- no fumbling there. It might be worth wiring it so that there is a seperate AF button, but have the shutter switch/button also connect the AF line, so you can release the AF switch first, and then release that shutter switch, opening both circuits at the same time.

stews Forum Member • Posts: 66
Thanks for the tip!

sez wrote:

think I found the workaround - just activate the mirror lock up in
Custom functions menu. In that case you press the switch for shutter
once - it locks the mirror, AF and exposure. Then you release and
press again - the photo is taken.

Thanks, I'm looking to take some Bulb shots tonight and the manual didn't explain the Custom Function to lock the mirror up well at all! This will be perfect, as whatever shake I cause when closing the shutter will happen for such a brief time that I can't imagine it will register.

Here's my second attempt at shooting the stars last night. It was for 30 seconds and I had to increase the exposure in the computer by 2 full stops! So I'll try your suggestion instead.


stews Forum Member • Posts: 66
Where's the link?

Dang it cut out the link to my photo on Flickr.

Here's the web page: http://www.flickr.com/photos/stewstryker/1375652071/

I can't get the to include the image even though I'm registered (free, is there a paid version?).

stews Forum Member • Posts: 66
Last try

I looked up how to post these in the Open Talk forum and it looks dead simple. Yet every time I post the JPEG URL, it gets cut. What's the deal???

Should have photo here:

And URL here:


This time, it all seemed to work. Sorry for the billboarding! :-/

Finally, Flickr requires that when posting an image on an external site, you post the link to the original Flickr page too. So trying to be a good Flickrite, here's that:


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