Power use of the E-3

About a year ago I tested the power usage of the E-510, which was interesting to me because I was planning a trip to africa at the time where every drop of battery juice counted. Hawing switched to the E-3 since, I've decided to run the same tests for the heavier camera.

While perhaps a bit esoteric for some, knowing how much power your camera actually uses in different configurations can be essential in stuations where you need to get the most out of your battery. Minimizing power usage can also speed up focussing with some lenses.

Note: While this article is about the E-3, many of the observations can be carried over to other Olympus cameras. In fact, most of this article was copied straight from the power use of the E-510 article, with just the numbers changed.

Setting up a baseline

The baseline is the starting point used in comparisons. It is a configuration with most options turned off. During this article if I say that a certain power usage is +20% of base it means that the camera is using 20% more power in that configuration than it did in the baseline configuration.

The baseline configuration is as follows:

• Shooting mode: P(rogram)
• LCD info: off
• Live view: off
• AF mode: S-AF
• Lens: ZD14-54mm II at 14mm
• AF Pattern: center-point

Note that these settings result in about the lowest power usage available. If you really need to save batteries, this is the configuration for you.

Conclusions

These are the detailed conclusions that I have reached based on this testing. If you just want the spicy bits there's a summary below. For the data these conclusions are derived from, look even further down.

Influence of autofocus mode

Focus mode matters considerably for power drain. The MF modes (AF-S+MF, AF-C+MF and MF) use about 25% more power than the baseline. This means that if battery life is an issue you should not leave the camera on these modes unless you have a good reason.

This MF difference did NOT apply to my Sigma 135-400mm. Presumably this is due to the mechanical coupling of the AF ring. This makes me believe the same will be true for ZD lenses with direct coupling like the ZD12-60. It is theorized that this may be due to the body having to continually poll the lens's focus-by-wire mechanism.

In ready state after a restart, S-AF and C-AF use the same power. However during a half-press S-AF will go to 56% over baseline (296 mA) and C-AF will go to 84% over baseline (350 mA). After the half-press, S-AF will return to the baseline but C-AF will go to a state that's still 13% over baseline! It will stay there until you restart the camera or switch to S-AF and back. Interestingly this residual power difference of 24 mA is exactly the same on the E-510.

There is no difference between S-AF+M, C-AF+M and MF during a half-press.

Influence of IS mode

Having IS on in ready state uses about an extra 9% of power, depending on the lens. However taking an actual picture with IS on makes this difference a lot bigger, see the live view section for some examples.

Noteworthy is that turning IS on and then off again sometimes leaves the current drain slightly higher than before until you restart.
Both IS modes use the same amount of current in ready state.

Live view

Live view yielded some interesting results.

For Most lenses, live view uses about 260% more power than the baseline (690 mA, that's about 3.6 times as much power).

This was true for my 14-42mm, my 135-400mm and my 9-18mm. It was not, however, true for my ZD 14-54mm II, which used the regular 680 mA at 54mm but used a whopping 810 mA at 14mm. This focal length dependant effect could not be replicated with any of the other lenses I listed, including the 14-42mm which has an otherwise similar view.

Using the x7 blowup in live view increases current drain to 252% over baseline (668 mA). This was true on both ends of the 14-54mm II. Note that this is slightly less than normal lievview power usage (for the E-510 it was an increase)

Live view power drain is independent of the amount of light in the scene. Bright lights and a closed lens-cap produced the same results.

Live view + IS

Just turning IS on during live view does not significantly increase power drain (just a few mA difference). However using the IS preview function (keeping the IS button pressed) gives us some interesting data on the IS usage.

Here it becomes clear that IS1 uses a LOT more power than IS2. There was a consistant difference of 70-80 mA between the two modes. For most lenses this meant a current drain of about 890-895 mA total for LV+IS1 and about 820 mA for LV+IS2 or about 260-270% higher than the baseline.

The outlier was again the 14-54mm at 14mm, which required a whopping 940 and 1010mA respectively for the two modes. The latter was by far the highest value that I recorded, though I saw some peaks going beyond even that

Compared to the E-510

I previously tested the E-510 in the same setup. Keeping in mind environmental aspects may influence the tests (they were performed a year appart after all, though with the same equipment), the E-3 still consumes considerably more power than the E-510. The measured difference between equivalent settings ranged from +7% (ready state with info showing) to +45% (IS on in liveview (but not previewing IS).  Speaking relatively, the differences between IS1 and IS2 preview have decreased since the E-510, as has the effect of using liveview magnification (which now actually reduces power).

Other findings

• Changing settings can make the baseline current drain go up. Turning the camera off and on again resets this.
• P/A/S/M has no effect on baseline
• Different Metering patterns (spot, highlight, ...) have no effect on baseline
• Baseline mostly independent of lens (difference of +-5%)
• Sleep mode (the one that triggers after about five minutes) lowers power drain to less than 10 mA, which is off for most practical purposes.
• Picture review in S-AF mode used avout 22% more power than the baseline. This is independant from AF mode, so if you're using one of the manual focus modes picture review actually lwoers power consumption.
• The choice of AF pattern had a small and probably statistically insignificant difference of about 1%, with single-point being the lowest and multi-point being the highest.

Summary of findings

For those who don't want to read through all the text before, here's a  summary of the more interesting findings.

• AF-S+MF, AF-C+MF, MF modes use 25% more power than the baseline (ca 50mA)
• The above was not true for my Sigma lens, possibly cause it has mechanical coupling
• Half-press uses about 56% more power than baseline for AF-S, 84% more than baseline for all others.
• After Half-press on AF-C power useage remains higher than before
• IS modes use about 9% more power in ready state (not taking a picture) than the baseline. This was the same for both modes
• Power usage remains higher even after turning IS off, until restart.
• Live view uses about 3.6 times as much power as the baseline for most lenses and most focal lengths
• The 14-54mm II uses a lot more power in live view at 14mm than any of my other lenses. At 54mm it uses the same as the others. Difference between 14mm and 54mm: about 20% power.
• All other lenses use more or less the same independent of focal range
• Live view power usage is independent of the amount of light in the scene: Brightly lit or lenscapped made no difference.
• using the 7x blowup decreases the power usage compared to normal liveview. This is the opposite behaviour from the E-510.
• IS1 uses more power when active than IS2 (about 40mA more)
• Highest power drain measured was 1010 mA, this was using IS1 preview in live view on the 14-54mm at 14mm. Same operation on other lenses (or at 54mm) used about 890mA
• Changing settings can make the baseline current drain go up. Turning the camera off and on again resets this.
• Even with that, power drain creeps up over time, presumably as things heat up
• Choice of AF pattern had an insignificant effect (1-2%), even in C-AF mode

Measured Data

This is (a subset of) the data as measured. Generally every line is the average of 5 or more measurements. If you want you can skip to the conclusions below.

 Columns

• #: Line number
• IS: Image Stabilizer setting used. Can be Off, IS1, IS2 or IS1/2 (meaning same resulst for both modes)
• LV: Live View: can be on or off
• Display: What was being displayed on the back LCD. Can be Off, Info bright, Info dim (when the LCD is in lowpower mode) or LV (live view)
• FL: Focal Length
• Current is the power drain in milli ampères( mA)
• delta is the difference with the baseline. Note: +100% means power use was twice that of baseline.
• Half-press: current whiel the shutter is half-pressed, in mA