Tuesday, 26 January 2021

Prudence as a camera - part 2

And now the Big Zoom Contest

Spoiler: There's only one possible winner! But the runner-up was worthy in other respects. Both get a prize, but for different things.

In the red corner, the little Leica D-Lux 4, a compact digital camera launched in 2008. This particular model was bought in 2009. It has (in full-frame terms) a 24mm, f/2.0-f/2.8 zoom lens, which goes out to 60mm (which is only 2.5x). It has a 10 megapixel sensor.  

In the blue corner, the Samsung Galaxy S20+, a large smartphone launched in 2020. This model was bought in 2021. Its lenses were described in the previous post; but in brief, it can zoom from 13mm (0.5x) out to 840mm (30x). It has a 12 megapixel sensor, but can provide 64 megapixels in HD. 

The test involved walking around Lewes, the county town of East Sussex (still in lockdown terms 'local' to me), taking pictures of the same subjects with each device. The object was to capture what each could do with a particular scene, and from that deduce which device turned out the more attractive/revealing/true-to-life/technically perfect picture. It was a bright, clear, late-January afternoon, with sunshine and a blue sky.

I have a consistent tendency to shoot pictures tilted slightly down to the right. So both devices' shots have been corrected so that they seem upright, with a level horizon. 

In theory, Samsung's in-phone algorithms combine to produce a perfect, finished picture - so that the user has nothing more to do. I have therefore made no corrections whatever. The S20+'s shots are just as they were taken, with no post-processing apart from the tilt correction mentioned above. 

The Leica has no such sophisticated software. So I set it up to take a standard, neutral picture which will almost certainly need later correction in some way on the laptop, if only for tilting and sharpening. So the Leica's shots have all been post-processed to make them as good as they can be.


Taken from the Old Needlemakers car park, off West Street. 

Below, and throughout these tests, the Leica's photo comes first, then the S20+'s. First, the basic shot of the Auction Room clocktower at 24mm for the Leica, 26mm for the S20+, i.e. with no telephoto effect at all:

The S20+ puts one closer to the subject throughout, even at this basic setting, with plenty of detail apparent; but with stronger, more intense colours than in real life. (These things are consistently true throughout the tests) 

Now, shots at the Leica's maximum zoom of 2.5x, and the S20+'s 4x setting:

The clocktower isn't much closer in the Leica's shot. But the Samsung's 4x zoom setting spans the distance much better, yielding a sharp and attractive picture, with all the interest you gain when a closer view is possible.


Taken from the approach down Abinger Place. First, the basic shot at 24mm for the Leica, 26mm for the S20+, i.e. with no telephoto effect at all:

As before, The S20+ puts one a bit closer to the subject, even at this basic setting, with plenty of detail apparent; but again the colours are more vivid - and warmer - than you'd see in real life. 

Now, shots at the Leica's maximum zoom of 2.5x, and the S20+'s 4x setting:

The rest of the shots are from the Samsung, at 10x, 20x and 30x:

10x (280mm in full-frame terms) is the most satisfying of these more extreme telephoto shots. The detail is quite sharp and clear, camera shake being dampened enough not to be obvious. I thought that was a golden lion on the wind-vane, but the 10x zoom reveals it to be an Agnus Dei - the Lamb of God. I wouldn't have known that without such a good zoom.

I don't have shaky hands, but I still found it hard to hold the phone steady enough to use the 20x and 30x zoom settings. The view jittered around on the phone screen. As indeed it does when you hold high-powered binoculars, and try to see something through them. 

The results at these more extreme zoom settings are remarkable for a phone, but not good. I'm sure there have been ultra-rapid in-phone corrections to mitigate the wobble, but even so, the pictures are substandard. In my view, it's not worth using the zoom beyond 10x unless the phone is locked onto a tripod. Even then, it's asking too much of a 12 megapixel sensor to capture fine detail with everything made distinct. Smudging is bound to occur. 

It's different (as you will see in the final test) if you use HD and bring 64 megapixels to bear. But then, that's means a really large photo file, and precious memory gobbled up. All right for a one-off shot, though.


Taken from the path that skirts the Ponds and runs down to the River Ouse. First, the basic shot at 24mm for the Leica, 26mm for the S20+, i.e. with no telephoto effect at all:

Now, shots at the Leica's maximum zoom of 2.5x, and the S20+'s 4x setting:

It's not so clear to me that the S20+ wins. I think it does have the edge, but the Leica can do natural foliage better. That's pretty general: where the subject is man-made, and has distinct edges, this phone excels. Where the subject is natural - including people - it may not get it quite right.  


Taken from the road bridge over the river (the Phoenix Causeway). First, the basic shot at 24mm for the Leica, 26mm for the S20+, i.e. with no telephoto effect at all:

Now, shots at the Leica's maximum zoom of 2.5x, and the S20+'s 4x setting:

The interest here is the detail of the obliquely-sunlit brewery building and chimneys, and the stacked stainless-steel beer casks. The Samsung has brought out very crisp detail with the 4x zoom. I like the Leica's rendition too, but it can't compete on sheer clarity of detail. 


Taken from the Eastgate car park, opposite the Brewery, with the river in between. First, the basic shot at 24mm for the Leica, 26mm for the S20+, i.e. with no telephoto effect at all:

Now, shots at the Leica's maximum zoom of 2.5x, and the S20+'s 4x setting:

Next, shots at the Samsung's 10x, 20x and 30x zoom settings:

And finally, a Samsung shot at 6x, but in HD:

With regard to the 10x, 20x and 30x shots, it's much as with Test 2, the church. The HD shot is however decent enough, certainly a usable option if 4x doesn't get one close enough. It would definitely be my choice if a subject were particularly far away, and I wanted to capture as much detail as possible. I will be testing it out soon on my tripod, with the phone aimed at the Rampion Wind Farm out to sea. But for ordinary purposes, I stand by my previous judgement that the 4x zoom is the nicest and easiest to use.

So which device wins this zoon contest?

It's a no-brainer. The Samsung Galaxy S20+ beats the Leica, hands down, on zoom capability. 

That said, the Leica produces very good pictures from its smaller sensor and its much more modest zoom range. And there's the advantage that its colours are true. The Leica also gives me pictures that can be worked on - either subtly improved, or taken away into artistic territory. Whereas the Samsung's shots are almost processed to death, and there isn't the same scope for further tinkering. 

But well done, both! 

I always carry my phone. So henceforth I will whip Prudence out to take any kind of zoom shot, mostly using that excellent 4x zoom. 

Otherwise, the Leica remains my go-to photographic device. It's especially good where colour matters, as in taking shots of food, where the wrong rendition can make a tasty meal look unappetising. Compare these shots, and guess which were taken by the Leica, and which by Prudence, my S20+:

Those were only small potatoes!

I hope you see what I mean about how you can make a meal look a bit off, if the coloration makes it look over- or under-cooked.  

Monday, 25 January 2021

Prudence (my new Samsung Galaxy S20+ phone) as a camera - part 1

Now the bit everyone will want to know about. (Although if you managed to afford one of these phones during the last eleven months, you'll already guess what I'm going to say. Just skip this post)

The Samsung Galaxy S20+ has three camera lenses, the main one having a 26mm focal length (in full-frame terms) and an f/1.8 aperture, which yields a 12 megapixels image. That's the lens to use most of the time. There is also a 28mm-840mm f/2.0 zoom lens, also 12 megapixels - although you can switch to 64 megapixels instead, which gives you High Definition, good for very distant subjects. Then there is a super-wideangle lens, with a 13mm focal length; I'm not sure about its aperture, nor how many megapixels. Presumably f/1.8 and 12. 

There are optional one-tap zoom presets for speedy operation.  These produce pictures at the following focal lengths (in full-frame terms):

0.5x, as if using a 13mm prime lens

2x, as if using a 56mm prime lens

4x, as if using a 112mm prime lens

10x, as if using a 280mm prime lens

20x, as if using a 560mm prime lens

30x, as if using a 840mm prime lens

If using the HD setting, the S20+ can manage a 6x zoom, as if using a 168mm prime lens, but nothing longer. But then all those extra pixels allow additional magnification, or cropping without much falloff in quality.

The S20+ achieves these zoom settings partly by optical means, partly by amazing in-camera processing. The intention is clearly to produce a finished picture that needs no further attention before instant (maybe even automatic) sharing on social media. Nothing wrong with that aim. It's what many people want, after all. To create a shareworthy or publishable picture, however, various enhancements are made to make the shot look bright, clean and crisp. Every shot is a composite of a rapid burst of shots: the phone analyses what it captures, selecting only the 'best' pixels from each part of the picture, and binning what seems indistinct. The technique produces shots that are undeniably pleasing. 

But a conventional camera would capture all the little things that have been discarded. Such as subtle facial blemishes. Samsung's phone cameras will smooth most of those away. Does it matter?  Not if you want a flattering shot! But if you're brave enough to want a totally honest and truthful rendition of a face that age has withered and custom has staled - your own, it may be - then a 'proper' camera like my little Leica is the one to use. Putting that differently, if I wanted my doctor to have a clear and realistic shot of a rash or cut, I'd use the Leica. If I wanted to convey the true colour of a piece of fabric, or a carpet, I'd use the Leica. 

It's horses for courses. I'm impressed with Prudence's zoom abilities, up to 10x anyway. I intend to use them when I need a closer view, and it's inconvenient or impossible to move myself nearer

But for nearby shots that don't need a zoom, Prudence has little advantage over the Leica. The Leica's output is definitely more natural-looking, with more accurate colours. And at all times, the Leica is the better device to hold and operate. 

On my first evening with Prudence, I took a few shots, just to see what she could do in the subdued lighting conditions close to midnight. Here are two of them.

I corrected those two for tilt, but the rest of Prudence's shots below haven't been altered in any way. They are exactly as they were taken. 

To begin with, I merely experimented with the phone, to find out what the picture-taking experience was like. The answer? Much as before with my previous phone - meaning that it would be no disaster if I ever had to fall back on Prudence and use only her. The camera is that good. Here are some indoor shots at home, showing a variety of colours and textures:

Nothing to complaint about in those shots. But then it's easy for any camera to take good pictures of inanimate household objects! Let's continue.

Then I decided to try out the zoom, starting at 4x.

Well that looked interesting! I decided to explore the zoom more. Yesterday I was in Storrington, and took these shots of the Tesco Express filling station there. 4x zoom again. It was less than an hour before sunset, and the light wasn't all that good.

This zoom business needed a structured examination. So today I went down to Lewes and took a series of careful comparison shots with the Leica and the S20+. It was a perfect, sunny, blue-sky afternoon. The results, and my overall verdict? 

Next post. Tomorrow.