Magic Lantern Forum

Developing Magic Lantern => General Development Discussion => Topic started by: yourboylloyd on September 17, 2020, 01:29:46 AM

Title: Power Usage Comparison/Investigation
Post by: yourboylloyd on September 17, 2020, 01:29:46 AM
Thought that this could be useful for understanding the camera hardware.

Background: A1ex, names_are_hard, and I had a random off topic conversation in the discord chat about overheating on DigicX. We were comparing the 5D to the R6 as far as power draw from the internal battery. Then I realized that I have an accurate way of measuring this and could perform a test!

Test setup:
Using a LP-E6 dummy battery, an AC adapter for the dummy battery, and a TPlink Smart watt-meter. I was able to measure the power of the cameras in their different states. I have the 5D2 and the R6, but this test can be measured on any camera!


The AC adapter naturally uses 0.3W of power. So subtracting that from the readings I get and getting an average

5D2: (+/- 0.5W on all tests)
Power on (no liveview): 2.56W
Liveview on: 7.21W
Recording H.264: 8.4W
Recording 1044p RAW: 8.59W
Recording 2.7K RAW MLV 24fps: 8.35W

EOS R6: (+/- 0.5W on all tests)
Power on (flipped screen into camera): 1.6W
Liveview on LCD screen: 4.1W
Recording 4K 60fps: 10.6W
Recording 4K 60fps with stabilzation on while shaking cam (IBIS): 11.8W
Recording 4K 60fps with AF on (35mm lens) stabilzation on:OVERLOADED (>12.58A)
Shooting in 20fps photo burst mode: OVERLOADED (>12.58A)
Recording at 4k 24p no usb c charger: 9.8W
Recording at 4k 24p with usb c charger plugged in: 9.82W (basically the same)
[(this confirms that the usb c only charges the battery and does not power the camera at any point)]

So the R6 draws significantly more power from the LPE6 batteries than the 5D2. I can only imagine that a R5 recording 8K RAW to a CF express card could draw closer to 16W.

I would love to see this test performed on other cameras! Even the blackmagic4k would be interesting. I'll update this first post if anyone can post a reliable test of this on a camera.
Title: Re: Power Usage Comparison/Investigation
Post by: b on September 18, 2020, 12:28:52 AM
I was encouraged to share my own findings on the M50.

My setup is using a dummy battery as well, but the power supply I have for it has a USB cable and a little step-up converter in the cable, and I have a USB power measuring device meant for testing USB power supplies as well as the power draw of USB devices. This sort of makes comparison vs the kill-a-watt method a little more difficult (for one, the measuring device is measuring at 5V DC instead of mains voltage AC), but it’s still good data.

Additionally, my power meter updates about once a second, which is far from ideal. I had to redo a number of measurements and estimate a little, too.

Anyway, here’s my data, for the Canon EOS M50. The power supply I used varied between 5-5.17V, which is within USB spec, but I am getting the wattage from a nominal 5 volts for sanity/calculation ease.

Camera on, idling: usually between 0.3-0.5A, (1.5-2.5W) but can peak to 0.7A (3.5W)

High speed burst mode at 1/160 shutter and 3200 ISO: peaked at 1.24A (6.2W)

Burst with flash at 1/160 and 3200: peaked at 1.30A (6.5W)

High speed burst at H/51,200 ISO: peaked at 1.34A. (6.7W)

4K@23.98P filming, while racking manual (STM lens) focus back and forth and shaking the camera (IS enabled): peaked at 1.05A (5.25W)

The short answer is that the camera is ridiculously power efficient. It appears that the biggest peaks were due to SD card writes, rather than much on the part of the camera body.

I want to mention that I did my best to estimate worst-case scenarios here. I used a lens with moderately fast STM focus (EF-M 15-45mm STM), I used autofocus and image stabilization on max, and I shook the camera while recording. I also had WiFi enabled and connected to the Canon app on iOS for some of this, though that in particular really didn’t seem to impact the readings at all and I didn’t keep any real logs of that.

But at the end of the day, this is a ridiculously power efficient camera for what it provides.