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Astro-Landscape & Long Exposure Timelapse Testing For Mirrorless Cameras: External Battery Power

Since acquiring one of the most amazing compact super-zoom digital cameras ever, the Sony RX10 mk2, I have been earnestly testing Sony’s USB power input. All of of the newer (mk2) A7-series mirrorless full-frame bodies, for example, can run off a 5V power bank using a USB cable. (Previously, the Sony USB port could only charge a battery while the camera was off, apparently.)

My goal is to see just how ready (if at all) mirrorless cameras are for all-night astro-landscape timelapse shooting.

TLDR: using the highest capacity external battery sources, so far I am very impressed and moderately excited about mirrorless cameras finally being ready for astro-landscape timelapse work! Unfortunately a few quirks do still exist that may be show-stoppers, for the time being.

Sony RX10 II Moon

Nightscape Timelapse Testing Details

  • The Sony RX10 mk2 uses the same battery as the full-frame and APS-C mirrorless systems, the Sony NP-FW50. It’s ~7.2V and a paltry 1020 mAh. (A Nikon EN-EL15 is 1900 mAh)
  • Thanks to the much smaller sensor, the Sony RX10 mk2 is actually CIPA rated to get slightly better battery life out of the NP-FW50 than, say, an A7RII. (400 vs 360)
  • Unfortunately, all mirrorless cameras gobble up those mAh much faster than OVF DSLRs do, and this puts mirrorless cameras at a huge disadvantage for battery life, period.

Considering all these relevant details, the RX10 mk2 gets about 60-90 mins of continuous, back-to-back 30 sec exposures on a single NP-FW50. That is about 1/3 or 1/4 what a FX or DX DSLR would get. The DSLRs are able to operate without live view running continuously, this saves a ton of power. And even though some of the newer mirrorless cameras allegedly have options for turning off the LCD and EVF while shooting, the bottom line is that the Sony NPFW-50 battery is also about half the capacity of most DSLR batteries.

wigwam-motel-rialto-09Sony RX10 mk2, 30 sec @ f/7.1 & ISO 100, 3-image panorama

Using External Power With Mirrorless Cameras For Timelapse Work

First, I bought an Enerplex QuickCharge 8000 USB battery and ran an all-night timelapse to see just how long 8,000 mAh would carry the RX10 mk2.  Theoretically, if it can do ~1 hr on ~1,000 mAh, it should be able to do ~8 hrs on 8,000 mAh.

The first attempt was 990 30 sec exposures at 47 sec intervals, which would yield nearly 13 hours of shooting.  The 8,000 mAh battery pack died some time during the night, and the RX10 mk2 was not able to switch to its in-body battery to continue the timelapse apparently. But, at least the external battery lasted for almost the entire 13 hour duration / 990 exposures.

The second test was again 990 (this is the limit of the built-in timelapse app that you can buy for $9.99; hopefully they’ll have an update that can change this!) 30 sec exposures at 33 sec intervals, yielding ~9 hours of essentially continuous sensor….sensing. The external battery pulled off the 990 exposures no problem, then the camera sat idle for ~3 more hours after sunrise, and still had somewhere between 30-50% charge left. (I slept in. I hope the Sony timelapse app also gets an update to allow the camera LCD to sleep after a timelapse is complete!)

Enerplex QuickCharge 8000

Note, this is a 5V, ~1 amp output device, and the cameras operate at ~7.2V.  (They claim the QuickCharge is capable of 1.5A output, however, Amazon reviews state that this basically operates at 1A to avoid overheating) Either way, going from 5V to 7.2V is, simply put, a bit wasteful. The limitation of 1A instead of 1.5-2 is probably not helping either. (You can buy 7.5V-12V battery packs for various other purposes, however, 5V USB power banks are by far the most popular because that is what most folks use to charge their phones and tablets on-the-go. Also, most variable-voltage battery packs are much more expensive, like, 5-10 times more expensive!)

Eastern Sierras Hot Springs Moonlight Star TrailsEastern Sierra Hot Springs By Moonlight
Sony RX10 mk2, 40 mins worth of 30 sec exposures @ f/2.8 & ISO 800

Anker PowerCore 20100

Clearly, a single 8000 mAh battery pack would be enough for 1-2 simple nightscape timelapses of 4-5 hrs each, and if you’re on a roadtrip with AC power access in a vehicle during most of the day, this might be all you need.  But, what about backpacking in the middle of nowhere for 3-5 nights? I decided, go big or go home, and bought the Anker PowerCore 20,100 mAh USB battery pack.

With this battery pack, I wanted to perform a different kind of test first.  Instead of powering the camera directly from the battery pack, I wanted to see how many re-charges I could put into the Sony NP-FW50 itself while the camera was off. (If a Sony camera is turned on while plugged into external power, it directs that external power straight to camera operation, and does NOT charge the battery while the camera is operating.  You can only charge the NP-FW50 in-camera via USB if the camera is turned off)

NOTE: Again, this is only the case for newer, mk2 versions of Sony mirrorless cameras. The older cameras, such as the A7R or A7S, cannot run directly off a USB power pack, and they can only charge the internal battery if the camera is off.

Considering that the NP-FW50 is ~1,000 mAh, at first glance you might hope that the Anker PowerCore 20100 would put ~20 full 100% charges into the Sony RX10 mk2.

In simple terms, you lose a lot of juice when charging one battery with another battery. (Even in Anker’s official spec sheet, the 20,100 mAh battery is only spec’d to charge a Samsung Galaxy S6 five times, and 2850 x 5 = <15,000 mAh.)

I was able to charge the 1020 NP-FW50 only seven times, and it took about ~3.5 hours to charge each time.  Considering you can kill these batteries in just a few hours while shooting, or in about 30-45 mins while shooting 4K video, that’s a show-stopper for anyone who is going to be away from additional power sources for more than 24-48 hours. If you want your mirrorless camera to last a few days, either bring a ton of pre-charged batteries, or be willing to go everywhere and shoot everything with your camera plugged in. (On a tripod, this isn’t so bad, just gaff-tape the Anker battery to one of the tripod legs.)

Anker USB Battery Powering a Sony RX10 II Timelapse

The next test I performed was much more promising, however.  I went with the same 990 shot, 33 sec interval, 30 sec exposure test on a fully charged Anker 20100. This time I managed to wake up right as the timelapse was completing. The whole thing didn’t even put a dent in the Anker’s 4-LED battery life indicator.

Stay tuned for continued testing results!  It seems that if you’re heading into the wilderness with a mirrorless camera and you wish to run some all-night timelapses, you should be good to go with the relatively lightweight (354g / 12.5oz) Anker PowerCore 20100 for at least a couple nights of shooting, and conservative daytime shooting.

However you might get 20-30% worse performance than what I got, if you’re using a full-frame mirrorless camera, so clearly this whole theory will require additional testing. And, for any system, whether it be RX-series, A7-series, A6000-series, you will still want to bring quite a few extra NP-FW50 batteries, simply because recharging them in the field is a rather inefficient option. Unless you plan on leaving your external power source permanently taped to your tripod and plugged into your camera, which may very well be a good option for some. ;-)


Mirrorless Loses Its Advantage Of Weight Savings

For landscape, travel, adventure, or nightscape photographers though, the “mirrorless advantage” is a bit difficult to figure out. Many of the bells and whistles that other mirrorless fans are raving about just aren’t relevant to us. In fact for me, I can only think of two reasons right now that I’d consider using a mirrorless camera for hiking and backpacking: weight savings, and accurate metering at night.

The on-sensor metering of a Sony is incredible, and allows you to shoot day-to-night transitional timelapses with ease. This is a huge advantage compared to a DSLR that seems to utterly fail at metering about 20-30 mins after sunset, which necessitates annoying bulb ramping calculations or constant exposure monitoring.


A #sunrise #timelapse shines on #Catalina Island and #NewportBeach, #California. #SonyRX10 mk2

A video posted by Matthew Saville (@matthewsavillephoto) on

Eastern Sierra Hot Spring Sunset Timelapse, December 2015

A video posted by Matthew Saville (@matthewsavillephoto) on

Unfortunately, the other advantage, weight savings, can cease to exist if you want to shoot lots of timelapse one of the larger sensor cameras like the A7R II. It’s only marginally lighter than a Nikon D750 to begin with, and the extra batteries required to feed the mirrorless camera would put it far beyond the tipping point.

Even if you also use an external battery to power your DSLR, you’ll only need a single 9-10 oz battery, whereas to shoot the same amount of timelapse you might need two 12+ oz USB power banks.

So, mirrorless loses its advantage, unless you’re shooting very conservatively. You could save even more weigh by using one of the older, lighter A7-series bodies, but then again that camera wouldn’t work with a plug-in USB power bank, you’d have to use a dummy battery like with a DSLR, and bring 2-3 external 7.5 volt batteries. (This is something I plan on testing asap) That, plus the fact that the older Sony A7-series mirrorless bodies are completely un-sealed from weather, equals serious hesitance on my part.

Lastly, you could do what I did: opt for a non-ILC compact camera with a 2.7x crop sensor, like the RX10 series. This would certainly save you weight, but it would also be a noticeable compromise in overall image quality. Or, there’s the Sony RX100 series, which currently offers a 24-70mm equivalent lens that hits f/1.8 on the wide end, which is certainly tempting at just 10 oz. Without question, I’d bring such a camera on a backpacking trip if I needed 2-3 cameras on that trip. We’re on a mission to find the best solution for a primary camera, though.

Therefore, it is my conclusion that mirrorless is certainly a viable option for nightscape timelapse work, but there are still a few serious improvements that could be implemented, and the DSLR option is still a great one, even for the weight-conscious photographer. (Although lightweight full-frame body options are a bit limited, I’d still consider them to be adequate for any type of professional work)

More Nightscape Wishes For The Sony Camera System

Before I wrap this up, I might as well collect my current wishlist for the Sony camera system here, including stuff I’ve already mentioned above:

  1. I wish the Sony timelapse app would allow the camera LCD / EVF to sleep (turn off) after a completed timelapse sequence, or even DURING a timelapse.
  2. The existing option in the Sony timelapse app for a dim LCD (“Monitor Bright. during Shoot.”) …does not seem to do anything, and it always resets itself back to “Normal” no matter how many times I set it to “Dim”.  Maybe the feature is broken, or maybe it’s because I already set my camera LCD to -2 for all nightscape photography in the first place.
  3. I wish all Sony mirrorless cameras were able to completely shut off the LCD during longer exposures, instead of just leaving the LCD on, but black / blank. This could really go a long way to increasing battery performance when all you’re doing is back-to-back 30 sec exposures!
  4. I wish the Sony timelapse app would allow more camera settings to be adjusted during a timelapse; currently things like WB, and even the physical EV comp dial, seem to be on lockdown once you start a timelapse.  This would be very helpful when capturing timelapses of the transition of night to day and vice versa.

So, that’s all for now folks!  Stay tuned for more test results.

Data and random notes are collected at:

Matthew Saville’s Adventure Photo Gear Chart

Take care, and happy trails,