The easiest way to ensure that your camera never runs out of power is to have enough spare batteries. However, when you don’t have enough handy, it’s good to know how to save some power and get more out of the batteries you have. Some advice can be found online, but usually unsupported by any numbers and so I decided to measure myself which settings are the best for power savings on X-T2 usage.
The most savings can be expected from turning off the Boost option in the Power Management/Performance menu. According to the X-T2 manual, it increases Auto-focus performance, provides better viewfinder quality and also increases viewfinder refresh rate from about 60 to 100 fps. So, quite some difference in the power needed is to be expected, let’s see:
And really, comparison of Boost and Normal modes, when the camera is on and doesn’t do anything else, shows that the Boost mode takes significantly more power, up to roughly 50% more when EVF is used. The difference is a bit lower when LCD is used, but is still a very significant one. Interestingly enough, even when neither LCD nor EVF is on, there’s still a lot of current drawn from battery and even more with the Boost mode. I’m not sure why the camera can’t conserve power better in this mode, looks like a poor implementation to me. The implication is, that turning the camera off when you don’t use it, is the only way to save battery, there isn’t any good alternative, like turning the displays off. You can either power off the camera manually, or rely on the Auto Power Off feature, both results in practically zero power consumption.
Another rather obvious way to conserve batteries is to reduce brightness of LCD or EVF. Lower brightness requires less light and thus also less power. The chart compares the lowest, default and highest settings for both LCD and EVF:
Apparently quite some power can be saved by using lower brightness. The +5 settings of LCD consumes about 17% more than the -5 settings. The savings aren’t that significant as in case of the Boost mode, but still very nice. There are cases when high display brightness is not needed, like for night photography, and then usage of the LCD at the lowest brightness can help to conserve some power for longer shooting.
There are few other settings that influence power consumption of the camera. The most important is Pre-AF, which increases the current needed by about 150 mA. So, it definitely makes sense to turn this off when not needed.
Strangely, X-T2 set to manual focus (MF) consumes slightly more power than in AF-S or AF-C mode by up to 40 mA (camera idle, no actual focusing done). I don’t understand why this happens, possibly it’s related to reading of the current focus distance from lens? Anyway, this probably won’t influence your shooting habits.
Then also the ambient light influences the power needed when camera is idle, unlike the ISO settings during exposure, which doesn’t have any effect. However, this fact is hardly of any practical use.
Until now the measurements involved only a camera that’s turned on and doesn’t do any operation. I was also interested in the effect of various modes on exposure though. During long exposures, there’s a countdown timer shown on LCD or EVF, which is a nice feature. Here is what difference it makes for power consumption in different brightness levels:
It’s interesting to see that EVF brightness doesn’t have any effect here, the countdown timer probably doesn’t respect the configured brightness level. Also, LCD configured to the lowest brightness doesn’t consume significantly more than both displays turned off and so there’s a very little reason to not have LCD turned on even for longer exposures.
Note that during exposure, there wasn’t any measurable difference for various ISO settings, Boost mode, Lens image stabilization or any other camera configuration.
For playback, both LCD and EVF modes take about 200 mA for the default brightness, with values ranging from 190 to about 260 mA for different brightness levels.
Compared to other cameras
I was also interested in how X-T2 compares to other cameras in Fujifilm’s lineup — an older X-T1 and also my backup X-M1 body. The comparison involves power consumption during long exposures, which should highlight difference in camera sensors.
The differences are surprisingly high! It looks like the new 24 megapixels sensor in X-T2 consumes much more power than the older 16 megapixels in X-T1 and X-M1, or possibly X-T2 isn’t as efficient as X-T1 is. Even when the same sensors are compared between X-T1 and X-M1, it’s clear that X-T1 is very efficient, there’s probably some better design in X-T1 which isn’t used in other Fujifilm cameras.
When you have enough spare batteries, it’s certainly easiest to leave camera at the optimal settings and don’t care much about its power consumption. However, when batteries are a concern, as can be on a longer backpacking trip, it’s good to know few tricks how to save some power.
Turning off the Boost mode saves a lot of power, while not having almost any negative impact for example on workflow of a landscape photographer. Also decreased brightness can help while keeping the camera perfectly usable in most conditions. It’s also usually more efficient to use LCD instead of EVF. And, the most important — turn the camera off when you don’t need it!
Based on the measured current needed for individual features, here is a checklist of things to do in order to save power (the most useful first):
- Bring enough spare batteries or a powerbank 😉
- Turn off the camera whenever not needed (saves 400-600 mA)
- Turn off the Boost mode (saves 150-200 mA)
- Turn off Pre-AF (saves about 150 mA)
- Use LCD instead of EVF and decrease its brightness as much as possible (saves 20-40mA), but in sunlight, when LCD must be set to higher brightness, EVF might actually be more efficient
If you look for spare batteries for your Fujifilm camera, check out the test the original NP-W126S and several alternative batteries in order to choose those that have the largest capacity and best thermal properties.