Battery Life... it isn't what they say it is...

So one of my cameras I use a lot is my Sony A6300. One of the common knocks against it is that it has horrible battery life. And in many ways, I would agree, that you are well advised to carry a spare with you. But that is if you shoot not thinking about saving battery life. Web reviewers will say two things about the camera. 1) It can't shoot sports. 2) the battery runs out way too fast. Typically after 300-350 images. For sports that can be limiting.

But here is the real story on number 2. It just depends. I am one who doesn't shoot automatic, almost ever. Last night I shot a women field hockey game for a local university, and at the end I had 971 images captures, and 67% of the batteries life left. Why the big difference? I shoot manual. I still use autofocus, but that is it. With an EVF I can see how I am doing on exposure every single shot. If lighting conditions change, I make the changes myself so I can control exactly the compromises I am making. Doing so has dramatically changed how much battery burn off I have. I easily get 3 to 4 times the published battery life.

The fact is that modern cameras a small computers. And as such, the less you ask them to do, the less energy they consume. The other side effect of doing so, the draw on the battery is a lot less, and so the amount of heat the battery is creating is a lot less. I've had over heating issues with my camera only three times in the three years I've been shooting with it. All three of those have been when shooting video, and I am not good enough with video to shoot it manual yet.

So the net of this is, the more thinking you do, the less the camera has to do, and the less battery drain you will have. I am not sure if this holds up for Canons or Nikons. I used to shoot 1D cameras, and battery life was never an issue. With he 7D and 50D, 20D, 40D, and 10D I shot, I did carry spare batteries. Im not sure if manually shooting would have helped them because I wasn't confident enough back then to shoot manual all the time. But I wouldn't be surprised to see them have the same results.

Anyway... my take away from this is if you are in a situation that your battery is getting low, a way to preserve it is to move to manual mode, if you shoot with Sony. Making the camera do less, saves a lot on battery. Keep only critical functions in auto... and do everything else manual. Even focus if your are shooting static subjects. You might be surprised by the change in your milage....

Croasdail wrote in post #18934646
I had 971 images captures, and 67% of the batteries life left. Why the big difference? I shoot manual. I still use autofocus, but that is it. With an EVF I can see how I am doing on exposure every single shot.

Your observations/conclusio​ns are very surprising to me.

As far as I can figure, the only electronic thing you are not using by shooting in manual mode is the light meter. . I would have thought that the light meter would barely use any battery at all.

Back in the film days, with my Nikon FE, the only thing the battery powered was the light meter. . Every other camera function was mechanical, not electronic. . I would stick that tiny little watch battery in my Nikon to power the light meter, and it would last for several months. . That is how little power a light meter uses.

With your Sony in manual mode, you're still using the EVF, which seems like it would use 100 to 200 times more battery power than the light meter. . I can't help but to think that there is something else going on within your Sony that causes such a big difference between manual exposure mode and the auto exposure modes.

It would be helpful if someone who designs camera electronics for a living would get on here and explain exactly what electronic components are being used in your Sony A6300 when shooting in auto exposure modes.

.

I agree about puzzlement that shoothing in Manual has that much effect on the Sony battery usage, especially in view of the the fact

• that the electronic display is always used,
  
• the sensor is always energized, and
  
• the main data processor always has to convert sensel data to pixel data, both for viewfinder purposes and for recording JPG files.
  

" I am getting at least 500 shots per battery using AF-C and shooting 8fps usually. Last weekend I took close to 2000 shots(started off RAW+jpeg but switched to RAW early on) at an airshow with two batteries. "

..to which another A6300 owner responded

"The more burst shooting you use, the less time chimping and reviewing shots, the less playback, the less video, etc. will all impact the battery life greatly."

Back in the day of the mercuric oxide cell in otherwise mechanical mechanisms, one battery would last a full year powering a light meter, even if you never switched it off! In fact, a number of those cameras had no on/off switch.

Tom Reichner wrote in post #18934680
Your observations/conclusio​ns are very surprising to me.

As far as I can figure, the only electronic thing you are not using by shooting in manual mode is the light meter. . I would have thought that the light meter would barely use any battery at all.

Back in the film days, with my Nikon FE, the only thing the battery powered was the light meter. . Every other camera function was mechanical, not electronic. . I would stick that tiny little watch battery in my Nikon to power the light meter, and it would last for several months. . That is how little power a light meter uses.

With your Sony in manual mode, you're still using the EVF, which seems like it would use 100 to 200 times more battery power than the light meter. . I can't help but to think that there is something else going on within your Sony that causes such a big difference between manual exposure mode and the auto exposure modes.

It would be helpful if someone who designs camera electronics for a living would get on here and explain exactly what electronic components are being used in your Sony A6300 when shooting in auto exposure modes.

.

I'm surprised as well, Tom. There has to be other factors at play in this scenario.

Croasdail wrote in post #18934646
The fact is that modern cameras a small computers. And as such, the less you ask them to do, the less energy they consume. The other side effect of doing so, the draw on the battery is a lot less, and so the amount of heat the battery is creating is a lot less. I've had over heating issues with my camera only three times in the three years I've been shooting with it. All three of those have been when shooting video, and I am not good enough with video to shoot it manual yet.

I'm a bit surprised and this heating phenomenon you've experienced. Having said that, I don't own a Sony and have no direct experience with them. But I have done a test on an LP-E6 battery which I described elsewhere.

When I do the test I've described above, the battery is barely warm, so it surprises me that you have experienced 'over heating issues with my camera." Something else may be going on that you are unaware of.

John from PA wrote in post #18934847
I'm a bit surprised and this heating phenomenon you've experienced. Having said that, I don't own a Sony and have no direct experience with them. But I have done a test on an LP-E6 battery which I described elsewhere.

When I do the test I've described above, the battery is barely warm, so it surprises me that you have experienced 'over heating issues with my camera." Something else may be going on that you are unaware of.

A number of Sony cameras have been reported in the past to have overheating issues in certain circumstances. A search on the web should disclose under what circumstances the reported overheating occurred. I just did Google on 'Sony overheating' and got 2,270,000 results.

We have, in the past, been warned about long exposure times and the sensor heating effect causing noise in the image...causing me to wonder what has happened since those days, that makes constant use sensor to feed the EVF in mirrorless to become a moot issue (or merely one hidden from the public?!)

I have to admit I wasn’t thinking of sensor overheating; my mind went to the battery since that was part of the original problem statement.

I have had a singular instance of an overheated sensor with my 60D and that was shooting a horse show on an extremely hot day here in the Philadelphia area. Probably 95 deg F and the camera was in the sun continuously. I was shooting short 10 to 15 second video clips and the camera coughed up an overheated sensor warning. I switched to another camera then switched back and forth for the balance of the show without any repeats of the problem.

Wish I knew guys what the difference was, but all I can do is report my results. Your mileage may vary..... but 2,000 matches up well with 900+ on 60 something percent of battery left. Would be interesting to see what impacts CPU usage as you shoot.

I do know comparing old school light meters isn't even close to an apples and apples comparison. You didn't have the camera looking across an array of photo sites to determine evaluative meetings. Those old meters were not calculating in real time color balance... a lot more happening.

But still....

Croasdail wrote in post #18934957
Wish I knew guys what the difference was, but all I can do is report my results.

Did you put any research into your lens?

When I shoot any of my mirrorless or DSLR, there's no question there is a difference due to what lens, the size, its AF needs, and even zooming needs for power.

I would think that in terms of power usage (my guess only) the list would look something like this.
1. Flash
2. Internal circuitry (processors, memory, supporting electronics)
3. Back display
4. Lens/body IS
5. Auto focus
6. Shutter
7. Aperture
8. Sensor
9. EVF
10. exposure meter

Mot sure why setting exposure manually would have such a large effect.

Because modern cameras don't look at images and set values serially, particularly when you are shooting 10 frames a second. Between each frame shot, it has to compute exposure, focus, display image and data around the image in an overlay and produce an image in the evf that is being refreshed 60 times a second, apply color balance, activate stabilization if it senses movement, predicting the next location of the subject, apply color science and decode the image, convert the captured image to its storage format, write the image to a file with metadata, find the subject again and start all over. All in the course of 1/10th of a second.

Computationally that is a lot of calculated information. Each of these is a service running inside the CPU. By turning off some of these service, it reduces the total number jobs running concurrently on your CPU.

Just like your laptop. You can run applications that are CPU intensive, and your laptop battery will go down faster. The fewer jobs you have running in the CPU, the less power draw it requires. Each of these tasks, focusing, setting aperture, setting shutter speed, setting ISO, performing in camera HDR.... is a concurrent job running on the cameras cpu.

At least that is my understanding.

mdvaden wrote in post #18936460
Did you put any research into your lens?

When I shoot any of my mirrorless or DSLR, there's no question there is a difference due to what lens, the size, its AF needs, and even zooming needs for power.

I can see that different lenses would have different draw on the camera's battery based on AF focus system, IS efficiency, etc. Haven't really paid much attention to it since 80% are shot with my 70-200..... but who knows. Nor have i paid attention to if the lease has IS on or off.

EOS R CIPA battery life specs are 350 shots with EVF, 370 shots with LCD.

One day I shot over 2600 pics, saving RAW and Large JPG and also 20 something minutes of 4K video. I did not check remaining capacity.
I was only using EVF and did a fair bit of reviewing. I was using Sigma 500 f4 with 2X TC and IS. 2X TC means more AF racking back and forth as focus misses more often.

Without the 4K Video I probably would have made 10 times the CIPA rating for stills, ie 3500 shots.

Croasdail wrote in post #18936581
Because modern cameras don't look at images and set values serially, particularly when you are shooting 10 frames a second. Between each frame shot, it has to compute exposure, focus, display image and data around the image in an overlay and produce an image in the evf that is being refreshed 60 times a second, apply color balance, activate stabilization if it senses movement, predicting the next location of the subject, apply color science and decode the image, convert the captured image to its storage format, write the image to a file with metadata, find the subject again and start all over. All in the course of 1/10th of a second.

Computationally that is a lot of calculated information. Each of these is a service running inside the CPU. By turning off some of these service, it reduces the total number jobs running concurrently on your CPU.

Just like your laptop. You can run applications that are CPU intensive, and your laptop battery will go down faster. The fewer jobs you have running in the CPU, the less power draw it requires. Each of these tasks, focusing, setting aperture, setting shutter speed, setting ISO, performing in camera HDR.... is a concurrent job running on the cameras cpu.

At least that is my understanding.

Canon cameras activate IS on the lens as soon as the focus is utilized and leaves it on. IBIS would likely be the same, stabilization cannot be turned off/on during a burst.

Also on bursts, I haven't yet seen where each frame was a different set of exposure values, but maybe that is the case on some bodies, usually the metering is locked (again on Canon) upon focus, and then utilized for the burst.

During a Canon burst, only AF and mirror/shutter and sensor readout/processing to a file is occurring.

The largest battery draws, I feel, would be feeding lens power for stabilization and focusing, rear LCD display, a mirror if the camera has one, and GPS/WiFi. The rest is negligible when compared to this.

So if someone uses Wifi/GPS, and/or chimps alot on the screen, or has IS lenses that are activated all the time, or have large lenses, or are doing bursts, their battery life will be significantly different than someone shooting with a small non IS prime, only uses the rear screen in limited situations, and has their Wifi/GPS off.

Mirrorless switches out the mirror mechanics power and replaces it with an EVF drawing power (less of course) and then many more calculations per image than a DSLR, along with continuous AF if turned on, controlling the lens the entire time. The sensor on the R for example, is designed to handle 40x the computing power to handle all the extra programming going on.

Considering the EVF is on most the time where a mirror isn't moving all the time, and constant AF occurring with the sensor as you move around and aim the camera (ie the lens is being controlled), there could most likely be a larger power drain than the mirror. Mirrorless (at least some models) are likely more power hungry than their DSLR counterparts, potentially. This is why there is ECO mode on the Canon, to start shutting down displays, etc after just a small time period of unuse.

I have my M50 set up so that I just keep the rear screen flipped around and I don't use it. I use the EVF for everything. I can get more than the CIPA numbers on that camera too, primarily because of this one fact, I feel. My biggest issue around battery topics on the M50 is its battery life, but also its terrible battery level indicator. It could show 3 bars, and minutes later be flashing the replace battery icon.

Saving raw and JPG doesn't tax the system any more than normal (or very tiny extra). The JPEG has to be generated in all cases anyways, it is just that when you do raw, it doesn't save that out in a separate file.

Batteries aren't all created equal either.

There is no need to even use the JPEG option for output if you are willing to utilize a tool during post processing on all your raws to pull out the JPEG into a separate file at that time.