Taking a slight tangent from the core review coverage of the HP Elite X3, and in answer to numerous requests for a direct imaging head to head with the Lumia 950 XL, now that the X3 has had its camera firmware fixed up, here's a look using our interactive comparator. The winner can probably be guessed, since the X3 isn't claimed to have the best camera, but the device does have a few tricks up its sleeve....

Notes:

1. The Elite X3 still only shoots in 16:9 at 10MP - I'm still expecting a Camera update at some point to add other resolutions and aspect ratios back in. However, 10MP isn't a million miles from the 8MP oversampled images from the Lumia XL, so we don't have to worry too much about a mismatch for our comparator, below.
2. All shots were on full 'auto', except where stated.
3. In each case, in addition to 1:1 crops, I'm showing the scenes as shot by both phones, since colour balancing is often very different.

Note that the interactive comparator below uses javascript and does need to load each pair of images. Please be patient while this page loads, if you see a pair of images above each other than you've either not waited long enough or your browser isn't capable enough! You ideally need a powerful, large-screened tablet or a proper laptop or desktop. This comparator may not work in IE or Edge on Windows phones. Sorry about that.

Test 1a: Sunny scene

The house across the lake, a favourite test subject, here lit by weak winter sun. Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

Of the two, I think I prefer the less 'yellowy' Elite X3 snap. But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

Despite the slightly yellow-ish cast (but then the sun was low in the sky, so...), the Lumia 950 Xl photo definitely has more (and purer) detail, as you might expect. The PureView oversampling (such as it is) does work well, the OIS ensures a stable shot and the ZEISS lens means that nothing is compromised in terms of optics. Down at the pixel level, the Elite X3's shot is too red/brown and definitely has a more 'processed' look.

Elite X3: 7 pts, Lumia 950 XL: 9 pts

Test 1b: Sunny scene, but zoomed

The same scene, but zoomed by about 3x in the new Windows 10 Camera UI. Yes, this software's big Achilles heel is digital zoom and I fully expect both the zoom shots to be pretty terrible. But hey, this is science, so I'll press on....!

To look at the zoomed images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

Both are indeed awful (where's that Lumia 1020 when I need it?), but the zooming on the X3, despite having a lower resolution sensor to draw from, isn't appreciably worse than the Lumia 950 XL's shot. In fact, it might even be better - they each have a different 'impressionistic' quality.

Elite X3: 5 pts, Lumia 950 XL: 5 pts

Test 2: Sunny macro

A vivid red leaf, shot as close as I could, here lit by weak winter sun. Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

What HAS the Lumia 950 Xl done to the colouring here? The leaf is almost pink in its snap! Whereas the Elite X3 camera nails the actual colour of the leaf. And what's oddest about the difference is that the application, Windows 10 Camera, is supposed to be the same - so I have to put the difference down to camera drivers and firmware. Very odd! But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

The strange colouring aside (for which I have to dock the 950 some points), there's not much in it in terms of detail. Both show evidence of sharpening and edge enhancement, along with very good (shallow) depth of field.

Elite X3: 9 pts, Lumia 950 XL: 6 pts

Test 3: Leafy texture

Looking up to a patch of blue sky, artistically, through the leaves. Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

There's not much in the overall shots here, though the Lumia 950 XL saturates colours more, as usual. But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

Definitely slightly more resolved detail in the Lumia 950 XL shot, and we should remember at this point that I'm using the Lumia in its 8MP oversampled mode, i.e. that 16MP mode is also available if I really wanted to capture more detail. The X3 doesn't do badly here, but the lower native resolution and cheaper optics don't do it any favours here.

Elite X3: 7 pts, Lumia 950 XL: 9 pts

Test 4: Sunset HDR

My standard suburban scene, shooting into the weak setting (winter) sun, with HDR forced on in both devices. Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

Neither phone camera was able to cope with the brightest part of the sky. Perhaps not surprisingly. The HDR was more effective on the Lumia 950 XL overall, though. But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

The Lumia 950 XL is simply outclassing the Elite X3 here in terms of its physics. The OIS plus oversampling means that even areas of deep shadow come up with detail and almost zero noise, while the X3's photo is showing artefacts and noise - as you might expect. It's not terrible, but it's also not in the same league.

Elite X3: 7 pts, Lumia 950 XL: 9 pts

Test 5: Outrageous autumn colours

I couldn't believe the colour of this tree - it only lasted for a couple of days, but I captured it here in its full majesty. And no, HDR wasn't used on either phone camera - the tree really WAS that red! Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

The X3 nails the colour of the tree, to my eyes, while the Lumia's image is just a little too saturated. But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

There's very little in it in terms of detail and (sharpened) edges, so I'm going to give the win to the X3 because it gets the colour more correctly.

Elite X3: 9 pts, Lumia 950 XL: 8 pts

Test 6: Getting arty

I couldn't resist this arty shot through the trees. Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

At the 'snap' level I much prefer the Elite X3's image, with greener greens, as it were, and artier lens flare. But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

The Lumia 950 XL is clearly edging it at the pixel level with sharper detail, though in fairness, the exact focus point was tricky to replicate, since the leaf was moving in the breeze and I was reaching into the undergrowth to get the shot in the first place. So I'm going to call this one a draw overall.

Elite X3: 8 pts, Lumia 950 XL: 8 pts

Test 7: Indoor close-up

Some candles, lit through a sunny window and with plenty of textual detail to compare. Here's the overall scene, as shot by the Elite X3 (there was no real difference between the shots at this resolution):

Let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

Again, this is where the Lumia's PureView oversampling gets to work to reduce digital noise and artefacts, plus the ZEISS optics produce a clearer image in the first place. A win for the 950 XL, though the X3's image isn't terrible.

Elite X3: 7 pts, Lumia 950 XL: 9 pts

Test 8: Night time

Completely dark, save for the cycle shop staying open late. Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

Quite a difference, though the exposures (1/25s and 1/20s) weren't that different. What you're seeing here is a larger aperture letting in more light on the Lumia 950 XL. But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

A clear win for the 950 XL here, as expected. The Elite X3's more limited lens, smaller aperture and lack of OIS means that night time images look artificial - typical mid-range camera phone fare, while the 950's photo is simply excellent, only blowing out for the very brightest of internal shop lights.

Elite X3: 5 pts, Lumia 950 XL: 9 pts

Test 9: Dead of night

Let'spush light levels right down. Dead of night, with hardly any illumination. Here's the overall scene, as shot by first the Elite X3, then the Lumia 950 beneath:

A huge difference, with the OIS in the 950 XL allowing a shutter time three times as long and with the larger aperture letting far more light in. But let's move on to detail and 1:1 crops.

In case you want to grab the original images to do your own analysis, here they are, from the HP Elite X3 and Lumia 950 XL, click the links to download. And to look at the images in more detail, here are fairly central 1:1 crops, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

You know, that X3 image isn't that bad - it accurately reflected what my eyes could see/make out, while not blurring the image at all despite me shooting handheld (as usual). Either my hands are getting steadier or the exposure of 1/14s was just short enough not to show any hand-wobble problems. The Lumia 950 XL image is, technically, far superior, with genuine colours and detail, at around 1/5s exposure, though it's perfectly reasonable to argue that its image bore no relation whatsoever to capturing reality in terms of light levels. Genuinely, truly, 'turning night into day'!

Elite X3: 7 pts, Lumia 950 XL: 9 pts

Verdict

Although you won't be surprised at the overall winner here, it's instructive to tally the points:

1. Lumia 950 XL: 81/100 pts
2. Elite X3: 71/10 pts

The only surprise for me was how well the Elite X3 did, given its lack of imaging pretensions. I commented as much in my official review part. Quite a bit of the time it gets photos that are more accurately coloured than the top end Lumias, which is surprising since the software is supposed to be the same - I'm suspecting a bit of magic in the HP camera firmware. Look at the details at pixel level though and the X3's images are just a bit too vague, probably down to the generic lens used. Take light levels right down and the X3 struggles more, as you can see above.

The bottom line is that you might buy a Lumia 950 or 950 XL for its camera, but you probably wouldn't make that one of the major factors in choosing to buy an Elite X3. However, just because you bought the latter for its enhanced chipset and Continuum potential, for its durability, for its stereo speakers, doesn't mean that the camera is an also-ran - it's quite good enough in the vast majority of use cases.