Does a 350D use power to keep Shutter Open?

[george_harris3]

Hi Guys,

 

Sorry if this has been asked but I have searched but cant find the answer.

Does my 350D use battery power to keep the shutter open for long exposures? Im

off on my first star trails experiment and thats about the only question I

have left. I just want to know what to be prepared for. I will be away from

power for 4 days and dont want to use all my juice on the first night and not

be able to take pics for the rest of the holiday. If it does use power I will

probably forego the star trails.

 

Thanks in advance for your help.

 

George

 

PS I have a battery grip with 2 canon batteries in there and 2 spare batteries.

[peter_daalder]

Your 350D will most definitely use power to keep the shutter open.<br>For your reference, I have used a canon 5D with fully charged battery to take shots of the night sky. After about 45 minutes, I had taken 35 separate exposures and needed a second battery to continue shooting.<br> 4 days away from power? You will have to decide...

[tommyinca]

Yes. It use juice to keep shutter open. This is the same reason why the camera won't let you clean sensor unless the battery is fully charged. Also You may want to google dark current noise and red pixel in DSLR before planning to do a many minutes exposure. Digital sensor has different characteristic for prolonged exposure then film. You may not like the result you will be reading.

[radu_vadan]

Hi. I've done star trails with a 350D. It does use power to keep the shutter open, but not really THAT much. From what i can remember you can go for about 5 hours with a fully charged battery. Also, my trusty Elan 7e did a whole night on a set of CR123 cells and still had juice left the next day. The main idea is that 4 batteries will be enough if you're not shooting below freezing temperature.

 

Keep in mind the following two points:

- if it's cold the batteries will run out faster

- if it's wet your lens will get dew on it and all you will get will be a fuzzy gray picture

[mr._b]

I'd get two more spare batteries. You can buy them for reasonable prices online.

[jim_karthauser]

Interesting question- I pondered this a while back with my 40D and star trails, but then remembered that obviously the image sensor is 'exposing' therefore it is drawing power, plus the camera's electronics will be fired up as long as the camera is on. How much power this all uses I'm afraid I couldn't tell you. I'd get some cheap batteries from eBay, as many as you can. Then shoot to your hearts content.

[george_harris3]

Thanks Everyone. The answer became so obvious to me when I started to read the posts. Thankyou very much. I have just learnt that it will be a full moon when I am away and rain/clouds forecast. I guess Ill be staying in my warm and cosy tent at night. Thanks Everyone.

 

George

[steve_dunn2]

<cite>the image sensor is 'exposing' therefore it is drawing power</cite>

 

<p>AFAIK, collecting photons is a passive activity; a charge builds up on each photosite in proportion to the number of photons that hit it. Only when it comes time to read that charge (at the end of the exposure) does the sensor do anything active that requires a significant amount of power.</p>

 

<p>I don't know specifically which models need power to hold their shutters open and which don't, but as a general guideline, the pro bodies tend to be more likely not to, and the consumer bodies tend to be more likely to require power. There may be a list somewhere (I used to know of one, dating back to around the late 1990s, saying which bodies up to that point needed power to hold the shutter open); I couldn't find one.</p>