Nexus 6P HDR+ Auto, does it work for you?

After trying on the Nexus 6P with HDR+ always on yesterday, I wanted to evaluate HDR+ Auto in typical situations where you want multiple exposures to recover shadows or highlights.

As you can see from the samples shared here the result is clear: HDR+ Auto simply doesn't work.
In all my attempts today, HDR+ Auto was unable to identify scenes with dynamic range challenges and in need for some tone mapping.
I remember that yesterday HDR+ Auto turned HDR+ On at least once but I was unable to reproduce that today in real world scenarios.


– The 6P camera exposure system can easily underexposue a central subject. It is common that you need to aid the exposure system by tapping on your subject (hopefully your subject won't be of dark color)

– HDR+ sometimes increases contrast and reduces the final dynamic range instead of extending it, giving the opposite result to what's desired. It does so unpredictably.

My tip would be to activate HDR+ as forced On since HDR+ Auto doesn't activate it in the obvious conditions requiring it on, unless you need to shoot several images quickly.
Then since the automatic exposure can't be trusted outdoor, you it is recommended to tap on subjects to expose for them, while the preview will often seem overexposed, HDR+ should usually re-expose the final image rendered and recover highlights in the process.

HDR+ in general needs work to avoid being counter productive randomly, and HDR+ Auto is useless as it is now.

#supercurioBlog #camera #Nexus #Nexus6P


In Album Nexus 6P HDR+ auto

Source post on Google+

Published by

François Simond

Mobile engineer & analyst specialized in, display, camera color calibration, audio tuning

18 thoughts on “Nexus 6P HDR+ Auto, does it work for you?”

  1. I feel that when I first got the 6p the auto HDR+ used to activate HDR+ more often than it does now.. I think it just auto activate when in extreme low light situation, but from my short trial I also think that I should force HDR+ if I am in an extreme low light or extreme contrast situation, otherwise it will just take longer and use more power to take the shot. This is not the same as I used the Nexus 5 that I think that all HDR+ shots would be noticeable better than those without HDR+ mode, in any situation.
    I also made a few 4k recording with OpenCamera app (not limited to 5 or 8 minutes) but I think most of the time I had an underexposed image even taping in subject but I had screen too dimm when recording not to overheat or waste battery so I didn't noticed at the capture time..

  2. And even with HDR+ forced on it still performs in interesting ways. I'm a Nexus 6 owner and the Google Camera V3 update brings an algorithm upgrade to it. HDR+ used to be multi-frame lucky imaging like and didn't have much thing to do with HDR. The tonal curve is nearly identical with some highlight compression taken from a lower exposure picture and much higher SNR with the averaging method. It also evaluates the area that is under full-well condition and compensates by using the darker exposed picture as the base so that you can bring up the shadows in post.
    V3 update finally brings some tone mapping. But it still mostly follows the old way of evaluating exposure. So it decreases the exposure to prevent hitting sensor's full well capacity. To force it do a decent amount of tone mapping, hit the darker area while leaving some over exposed areas. It is able to pull back some amount of highlights while preserving the shadow details. Though it introduces some annoying HDR ringing artifacts in areas of large dark edges.
    Leaving too little bright areas may cause HDR+ completely ignoring it.
    I think it does pretty well when capturing dynamic scenes. It's able to mask out moving parts in the processing and maintain good overall looking while the moving part has a significantly lower SNR.

  3. +Shinya Kougami thanks for sharing, my experience confirms your detailed observations.
    I'm gonna play with it again today with these guidelines to see if it performs reliably this way.

    I wish I had a Galaxy S6/Note 5 on hands as well for comparison. Samsung HDR implementation works like magic whereas Google's is so useless if you don't manually circumvent it's limitations.

  4. Thanks for the test. The results don't surprise me: traditional DSLR makers like Canon and Nikon have much more room to fit in such a feature and it does not work always neither. Suddenly here comes Google with a software solution that does all the magic in an instance. Yeah, yeah.

  5. +Shinya Kougami​​​ yes, BTW as a developer you can use Samsung hardware accelerated Tonemapping through their Camera SDK API.

    HDR+ is focused on improving the SNR on the Nexus 5X/6P (and does so brilliantly), focused on the amount of detail/resolution on Nexus 5.
    But they could absolutely tune its priorities to improving the dynamic range on on outdoor sunny scenes.

  6. +François Simond All features this set of solution provides are simply amazing. Actually increasing SNR is the base for greater DR and texture preservation. The loss of details on N5 is due to the noise reduction basically.
    They can actually use some shadow gain before saving the final JPG since the high SNR guarantees the shadow performance.

  7. Oh BTW, I just know the fact that Google Camera 3, which ships with 6p and is available on 6 as an update, is actually pulling RAW images instead of jpegs. This explains why Nexus 6 gets a huge improvement. Also that's why the color looks different when HDR+ is on. Stacking RAW images on a phone is really an awesome thing. However Google still have to put more efforts into scene detection and parameter tuning. There is still some room for improvements right now.

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