It seems as though lots of people enjoyed Alvin's viewpoint that the incredibly cheap Lumia 640 now makes a rather excellent little 'lite' version of the flagship 950 - although not mentioned by Alvin in depth, one of the core differences in terms of performance should be the capabilities of the cameras in each unit, and I couldn't resist pitching these two head to head in a real world shootout(!)

Now, with the underlying PureView zoom, the larger sensor and OIS, the triple LED flash, the phase detection auto-focus, the main camera in the Lumia 950 should be head and shoulders above that in the budget Lumia 640 and - you can guess what's coming next - in a real world 'normob' shootout I found the two to be much closer than you might think.

Notes:

• I'm not going into pixel-level detail in this case because the average buyer of a Lumia 640 (or 650, come to that) wouldn't expect anything out of the ordinary. So, with this in mind, I'm going to compare the results from the two smartphone cameras at typical 'social' resolution (I use 900 pixel width here, so do maximise your browser window).
• The Lumia 950 was used with the latest production version of Windows 10 Camera, while the Lumia 640 was used with 'Lumia Camera' and both were left on full 'auto', i.e. automatic flash and rich capture.

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!

Test 1: Sunny subject, unusual angle

Shot at Brooklands Museum on a day out, here's a shot underneath the nose of Concorde, very arty and touristy at the same time. In case you want to grab the original images to do your own analysis, here they are, from the Lumia 950 and Lumia 640, click the links to download. And here are the photos, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

Aside from the slightly wider field of view of the 950 XL, there's nothing to choose between the two shots. Perhaps not surprising, given the excellent light conditions, but still credit to the Lumia 640.

Test 2: Sunny subject, shot against bright sky

Another bright shot, this time of a VC10 tailplane against a blue sky. In case you want to grab the original images to do your own analysis, here they are, from the Lumia 950 and Lumia 640, click the links to download. And here are the photos, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

Again the photos are essentially identical, proving that we're going to have to make things much tricker if we're to catch the Lumia 640 camera out!

Test 3: In gloomy interior

This time inside a Wellington bomber from WWII! In case you want to grab the original images to do your own analysis, here they are, from the Lumia 950 and Lumia 640, click the links to download. And here are the photos, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

The difference here is not so much in the improved optics (though the OIS helps a little here), but more that the Lumia 950 has three times the LED flash power and a much larger aperture, so there's far more light being let in and recorded.

Test 4: F1-tastic

I couldn't resist this rare F1 car from the late 1970s! In case you want to grab the original images to do your own analysis, here they are, from the Lumia 950 and Lumia 640, click the links to download. And here are the photos, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

The lighting in this museum hall wasn't massively bright, but the Lumia 640 camera was still more than up to the job.

Test 5: Up close

More F1, this time with models, macro shots through glass in quite low light. In case you want to grab the original images to do your own analysis, here they are, from the Lumia 950 and Lumia 640, click the links to download. And here are the photos, just wait to make sure the page has fully loaded and then use your mouse or trackpad pointer to compare the images:

Aside from the extra bokeh effect from shallower depth of field, the Lumia 950 photo isn't appreciably better to the casual observer than that from the Lumia 640.

Verdict

So there we go then, proof of sorts that you really don't need a flagship camera these days for most subjects. Five years ago, the difference in quality of images from budget handsets to flagships was vast - think HTC Desire to Nokia N8? From about 2014 onwards though, provided you don't go crazy with needing ultra-low-light shots or zooming, there's not that much difference in the results to the casual observer.

And, if anything, this all backs up Alvin's contention that the Lumia 640 really can be thought of as a '950 lite' - the comments in that article seemed to indicate that the Lumia 640 camera was very weak, but I hope the results above prove that Alvin was right - the 640 camera is much, much better than you might have reason to expect.