Thursday, February 4, 2010

Learnings (Part 2): Time-lapse battery, shutter and aperture life

Time-lapse movies are cool.  Especially when they are really professional looking.  Some of my favourite time-lapse movies are made by these people:
I've made a couple of time-lapse movies which you can find in high-definition on YouTube.  Perhaps not in the same league as those guys, but it's still fun and rewarding anyway.

I hope to do a lot more, and have recently learnt some new techniques to maximise battery life and minimise wear on the camera.

On a SLR camera, every photo causes the mirror to flip up, the shutter opens and closes, then the mirror flips back down.  Being moving components, the mirror and shutter have a finite lifetime.  During a time-lapse you may be taking thousands of photos, therefore reducing the life expectancy of your camera.

These techniques can be used with the Canon 7D and 5D mk II cameras (and possibly others) to reduce mirror and shutter activations.

Live View mode eliminates the mirror flapping since the viewfinder is disabled.  Unfortunately as I found out here, under normal Live View operation (Silent shooting Mode 1) the shutter is activated twice for every photo.  If you select Silent shooting Mode 2, then a sensor reset is used instead of a first-curtain shutter meaning that only a single shutter activation occurs.  Eliminating mirror flapping not only extends the life of the mirror mechanism, but also saves on battery power consumption.

Using Live View in itself does use more power because the LCD is lit between each photo.  Here is a technique to turn off the LCD, simply connect the supplied A/V cable to the AV Out/Digital socket (the weird USB socket) on the side of the camera.  This will trick the camera into thinking you're using an external monitor instead of the LCD monitor and switch it (permanently) off.  Note using a HDMI cable doesn't work.

The battery life is (apparently) very long when the camera is used in this manner.  But, I'm yet to try it.

For every photo, the camera will also switch the aperture between two positions (except if you are using your lens wide open).  Surprisingly, people report success by half unscrewing their lens which results in the aperture staying in the desired position.  Instead, a better solution is to operate in Movie mode instead of traditional Live View.  This might result in a longer aperture life and/or some power saving.  The real gain from this technique though is to reduce flicker in the time-lapse image sequence.  Flicker can occur where the aperture does not open to the exact same position every time.

I hope these techniques work for you.  Please post links to your time-lapse movies.

Read about other things I've learnt here.

6 comments:

serkantoros said...

Hello firstly i wanted to thank you for your posts...secondly i wanted to warn you about something.

When shooting in Live View mode, sensor is continiously active, which (also mentioned in the manuals as "camera's internal temperature may become high during prolonged Live View or Video shoot" etc) will become hot, and may shut down the camera after some time, there is probably no risk of buring the sensor but it definately shortens the lifespan of the sensor which will eventually result in more noise..etc and when sensor becomes hot it also means more noise or incorrect exposure, WB etc...

so in my opinion using regular viewfinder shoot and disabling the review functions are safer than using live view tricks :)

-Serkan Toros
http://behance.net/serkant/frame

Mark Stead said...

@serkantoros: Thanks for your feedback. I hadn't considered possible impact on the lifespan of the sensor.

I guess taking time-lapse photography with a DSLR is then a choice of mechanical wear versus sensor wear.

Shooting a time-lapse of the stars, or when the aperture is forced to be stopped down may be relatively safe, but shooting sunsets is clearly going to heat up the sensor a lot more.

I guess Canon needs a new silent shooting mode, where the mirror is locked up (permanently) in non-live view. Basically the viewfinder & lcd would be inactive. The sensor would only activate when shutter curtains open/close during an exposure.

Hopefully Magic Lantern make progress on their 7D firmware replacement.

Carolyn Turner said...

Very interesting post indeed. You really did a good job on this one. Thanks!

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ade123321 said...

Magic Lantern has power saving mode which I believe turns off the sensor in between shots in live view. So that may remove the 'sensor always in' issue.

Mark Stead said...

@ade123321: Great, I'm keen to use Magic Lantern. I'm just waiting for Magic Lantern to leave Alpha status on the 7D.

STV TATCHER said...

Hi Sir,

Im having some trouble with my 5d mark ii recently while im doing time lapse using magic lantern and i just cant figure it out,Before while doing time lapse i use to see an image live view on my monitor either on photo or movie mode,and now when i switch intervalometer on its goes directly on movie mode it does`nt make photos it does only movie,,,can you please help me Sir

Thanks
Stvsky