Friday, 15 July 2022

HDR photos with a smartphone, built-in versus my own method

On this blog, I have published some examples of HDR photos before, which I created manually by relying on auto-bracketing features in digital cameras and combining the multiple exposure photos using Luminance HDR. One could argue that this is obsolete because pretty much every smartphone camera app nowadays has a HDR feature built-in. As I will show below however, this often leaves much to be desired and it still makes a lot of sense to produce HDR photos the manual way, be it with the smartphone camera or a ‘real’ camera.

My most recent smartphone is a OnePlus Nord, but its built-in HDR is a general nuisance. It only engages when it believes there to be a need for it according to some vague heuristic. Even when it claims to be enabled, sometimes the result shows no HDR at all, probably because it failed to find matches between the images. The latter usually happens when HDR is most needed, when taking photos of sunsets that result in high contrast.

This made me look for an alternative camera app that offers exposure bracketing, such that not only could I make HDR photos when I want to, I can also make them the way I want instead of having to rely on the half-baked algorithm built into the native camera app. I found Open Camera, which proved a great solution.

In this blog post I will compare some HDR photos taken with both the OnePlus camera app (and one with Open Camera's HDR), and HDR photos of the same scene produced with my own workflow, as explained in the article on my website which I recently updated.

Example 1: OnePlus' HDR versus mine. As usual with the built-in HDR tonemapping in smartphones, it tries hard to show details everywhere by pretty much steamrollering the intensities into one flat dull result. The overall image is too bright, lacks saturation, and does not represent the scene how I experienced it. My HDR image might look a bit dark in comparison, but it much better represents the sensation of the actual scene when viewed in its own on a big screen.

Example 2: again, the OnePlus HDR makes things too bright and it looks more like a daytime shot with some colour filter than a shot taken at sunset.

Example 3: same remarks as above.

Example 4: again, the OnePlus HDR makes the sky a dull mess, while all the interesting things are happening there.

Example 5: this time, the OnePlus HDR has roughly the same overall brightness as mine, but local details are lacking, especially in the darker areas where everything is just clipped to black.

Example 6: here I first show the result from the OnePlus camera app, then the built-in HDR of the Open Camera app, and finally my own HDR. The first 2 are similar although the Open Camera result has some artefacts that I sometimes also experience with Luminance HDR when I didn't use a sufficiently large range of exposures to capture all intensities in the scene. But again, the automated HDRs are too bright and have a yellowish tint that does not correspond with how I experienced the scene.

Example 7: again OnePlus versus mine, and again the colours in the OnePlus image are washed out and despite its overall higher brightness, details in the darker areas are lacking compared to my image.

Example 8: (added 2022/08/14) this was a particularly challenging image due to the enormous dynamic range. Obviously, the OnePlus app only takes 2 or maybe 3 photos with a rather limited exposure range, and lost the subtleties in the sky colours. The result looks harsh and overly bright. I switched OpenCamera to 5 shots with an exposure range of ±3 stops, which allowed to capture the scene as it was. I had to tweak saturaton more than usual to end up with a result that matches how I experienced this scene in the real world.


Again, if you want to make HDR photos the same way as I do, check out the article on my website. One of the things that makes it fun to process one's own HDR photos, is the fact that it brings back a bit of the magic that used to be experienced when taking photos on film, and only seeing the results later on when the film had been developed. It is not exactly the same thing, but producing the HDR image from the raw bracketed photos does have a bit of a feel of “developing” the images.

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