Author Topic: Intervalometer, Battery Life and long period time-lapse  (Read 850 times)

dlredbaron

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Intervalometer, Battery Life and long period time-lapse
« on: January 22, 2019, 12:31:20 AM »
I am trying to do a long-term time lapse of about 90 days.  I have no experience trying to run a time-lapse longer than an hour or two.  Does anyone know how battery life compares between using the ML intervalometer vs. using an external intervalometer?

Walter Schulz

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Re: Intervalometer, Battery Life and long period time-lapse
« Reply #1 on: January 29, 2019, 08:54:28 PM »
There are indeed key differences.
An external intervalometer has no problems to access the cam and thus ending powersave mode. ML's intervalometer however has to run all the time to do its job. It can not end powersave on it's own. Cam will not even enter powersave mode while intervalometer is active.
Therefore - in your use case - a tremendous difference in power consumption and battery life will occur.

But a word of advice: As an engineer I will never ever trust any software to run unattended over such a period. Proper engineering would involve something called a watchdog to act on software stalling or power failures. They are designed to restart a device in a proper manner after such mishaps. Unfortunately consumer devices are not designed to work with watchdogs in a pleasant way (for an engineer's paranoid mindset).
Instead I would recommend some single board computer (Arduino for example) with control to power input in your setup. It is able to turn on and off power as wanted (requires almost no programming skills) and trigger events (=actuations) as needed.
As long as cam is working and there is some kind of external power supply you are covered.

EDIT: Just realized there is a way to trigger a watchdog by intervalometer. Just by using cam's LED. But it makes little sense to me to use this option if cam's power supply will be switched on and off by this very external device.

If you don't understand a word I'm saying contact your local maker facility (I hope there is) or a friendly tech wizard you may know.
Photogs and videographers: Assist in proof reading upcoming in-camera help!. Your input is wanted and needed!

c_joerg

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Re: Intervalometer, Battery Life and long period time-lapse
« Reply #2 on: January 30, 2019, 08:36:58 AM »
I am trying to do a long-term time lapse of about 90 days. 
I am also trying a  long-term time lapse …
Currently I do that with my Powershoot and CHDK. There I switch between the recordings in the playback mode which saves a lot of energy.
https://chdk.setepontos.com/index.php?topic=9969.540
Would that be possible with ML?
I cannot find the post anymore but with the EOS M3 / M10 there was a function, where you could set the camera for a certain time in standby. Is there something like this with ML?

Instead I would recommend some single board computer (Arduino for example) with control to power input in your setup. It is able to turn on and off power as wanted (requires almost no programming skills) and trigger events (=actuations) as needed.
But especially for long periods you have to pay attention to the Arduino too (millis () overflow after 49 days).
6D

Walter Schulz

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Re: Intervalometer, Battery Life and long period time-lapse
« Reply #3 on: January 30, 2019, 08:55:15 AM »
But especially for long periods you have to pay attention to the Arduino too (millis () overflow after 49 days).

True, but there are routines to master this issue and - as in most such devices - there is a proper watchdog on board.
Photogs and videographers: Assist in proof reading upcoming in-camera help!. Your input is wanted and needed!

a1ex

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Re: Intervalometer, Battery Life and long period time-lapse
« Reply #4 on: January 30, 2019, 10:06:49 AM »
Currently I do that with my Powershoot and CHDK. There I switch between the recordings in the playback mode which saves a lot of energy.
https://chdk.setepontos.com/index.php?topic=9969.540
Would that be possible with ML?

Yes, but these are only useful if you operate in LiveView. Outside LiveView, i.e. in shooting mode with display off, the power draw is lower than in playback mode with display on (both configurations being available in vanilla firmware).

If you operate in LiveView, check the powersaving menu in ML, or try these in Lua:
Code: [Select]
camera.gui.play = true
camera.gui.menu = true
camera.gui.menu = false
lv.pause()
lv.resume()
display.off()
display.on()
-- etc, see api_test.lua for more

Some rough power draw measurements here.

Quote
I cannot find the post anymore but with the EOS M3 / M10 there was a function, where you could set the camera for a certain time in standby. Is there something like this with ML?

Canon menu - you could set the camera to turn off after 30 seconds. It is technically possible to change this timer from ML, but I don't want to get there (had a less than ideal experience when I tried this trick on the 5D3).

Standby - as in pausing DryOS and having the camera react to external events only, like button presses - is something Canon firmware does to save power when you turn off the main display. ML disables this standby mode (otherwise it won't be able to trigger the next image from the intervalometer). This trick reduces the power draw in about half (click for numbers).

In any case, you are not going to get more than a couple of hours with ML intervalometer, on a LP-E6 battery. Maybe about 10 hours (or about 20 without ML) if the camera really does nothing.



Tip: with an external power adapter, if the power switch is left to "ON", ML intervalometer will auto-start at camera startup, so I had no trouble with power outages during my timelapse attempts (the longest one was for 2 or 3 days).



Another tip: if you use the full-res silent picture option for the timelapse, it comes with powersaving out of the box. Just turn off the image review screen, or set it to 2 seconds. Power draw: same as in regular photo mode, minus the mechanical shutter actuations. Remaining battery time is printed on the screen, during the timelapse (with LP-E6 batteries).

c_joerg

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Re: Intervalometer, Battery Life and long period time-lapse
« Reply #5 on: January 30, 2019, 10:56:50 AM »
Yes, but these are only useful if you operate in LiveView. Outside LiveView, i.e. in shooting mode with display off, the power draw is lower than in playback mode with display on (both configurations being available in vanilla firmware).
Yes of course, I forgot this advantage of a DSLR ... 

Tip: with an external power adapter,
https://www.magiclantern.fm/forum/index.php?topic=21660


6D