Samsung Galaxy S20 Ultra vs. Samsung Galaxy A51: mid-range and top smartphone in comparison

After pitting the OnePlus 8 Pro and the Nokia 1.3 against each other in an unfair duel, it's now time for a comparison in which one of the smartphones is still significantly cheaper, but should have a better chance. This time, both devices even come from the same manufacturer: Samsung's flagship Galaxy S20 Ultra has to prove that the almost fourfold price compared to the mid-range Galaxy A51 model is justified.

Display: Dynamic AMOLED vs. Super AMOLED

The Galaxy S20 Ultra is larger and, at 220 grams, also heavier than the Galaxy A51, which weighs in at 172 grams. This means a difference of 0.4 inches in the display. The S20 Ultra has a 6.9-inch Dynamic AMOLED display and the A51 has a 6.5-inch Super AMOLED display. The edge around the touchscreen is slightly narrower on the S20, which doesn't make it any thicker on the A51.

Holding both smartphones directly next to each other, I notice subtle differences in the colour reproduction. The A51's display appears slightly cooler than the S20. I can't decide which I like better. On the other hand, the S20 can score points for its resolution, which is higher than that of the A51 at a maximum of 3200×1440 pixels. You can also increase the refresh rate from the usual 60 hertz to 120 hertz, making animations smoother. However, this does not yet work in every app and only with a resolution of 2400×1080 pixels - which the A51 also has.

Both displays have a hole in the top centre for the front camera and a fingerprint sensor further down behind the display, which I am not completely satisfied with on either model. Too often they don't recognise my finger. Conventional sensors are more reliable.

Technologically speaking, the Galaxy S20 Ultra has the better and larger display, but the touchscreen on the Galaxy A51 is also excellent.

Which quad camera is better?

Both smartphones have four camera lenses on the back. Even a glance at the data sheet reveals major differences. However, these ultimately relate less to the image quality - at least during the day - and more to the photographic possibilities.

The Galaxy S20 Ultra has a main camera with a 108-megapixel sensor. The software normally always combines four pixels into one. This should improve the image quality and make the files smaller. The same principle is also used in the 48-megapixel main camera of the Galaxy A51. Both smartphones have a wide-angle camera with a resolution of 12 megapixels. Samsung equips the Galaxy S20 Ultra with a telephoto lens, behind which there is a 48-megapixel sensor and a 100x zoom. This is more Marketing than really useful. The camera delivers good results up to a tenfold zoom. The A51 does not have a telephoto lens. Instead, Samsung has installed a macro lens with five megapixels. The fourth camera is a depth camera that provides information so that the software blurs the background in "live focus".

Without HDR mode, the Galaxy A51 finds it much more difficult to equalise strong contrasts. The S20 Ultra not only gets more details in the shaded areas, but also in the clouds, which are overexposed in the A51. With HDR mode active, the A51 shows a number of improvements. The image from the S20 Ultra, on the other hand, remains almost unchanged, but still has the richer, more saturated colours.

When I view the images in their original size, the different colours are still clear, but there are no noticeable differences in the level of detail. The significantly higher output resolution of the S20 Ultra does not have a positive effect here.

Not surprisingly, there are no differences in the level of detail in the wide-angle shots. However, the images are not completely identical despite the 12 megapixel resolution. The colours of the Galaxy A51 appear somewhat stronger and I like them better.

As soon as it gets dark, the Galaxy S20 Ultra outperforms the Galaxy A51 and justifies its high price. Even in conventional automatic mode, the differences in terms of colour and detail are clear. In night mode, both cameras brighten the images, but the colours and details of the S20 Ultra are significantly better. The viewing angle of the A51 is reduced.

The darker the surroundings, the clearer the advantage of the S20 Ultra. To my eye, the playground looked similar to the photo of the Galaxy A51. However, with an exposure time of ten seconds, the S20 Ultra manages to capture the little stray light from the street lighting and compose a sharp image. The picture was taken by hand. No human could hold it steady without software help.

On both smartphones, the front camera is located in a hole in the display. The resolutions are high for front cameras with 40 megapixels on the S20 Ultra and 32 megapixels on the A51. I find the difference of eight megapixels negligible. A look at the pictures also shows that the problem with the A51 is not the level of detail, but the colour reproduction. The attributes "overexposed" and "pale" best describe the selfie - especially in direct comparison to the S20 Ultra.

It gets much better when you activate HDR. I actually like the way the A51 handles the contrasts better here. In contrast to the S20, the cloud in the sky is easy to recognise. However, the S20 Ultra still manages to reproduce the colours better. The image looks fresher.

The colour rendition also remains the plus point of the S20 Ultra when you activate live focus for selfies to blur the background. In contrast, I can't see any significant difference when cropping my head and the level of detail in the shots.

In the dark, the image quality of both front cameras drops significantly. However, I find that the A51 delivers the better night selfie than the S20 Ultra.

You can find the photos here in full resolution.

Clearly better on paper, but not in reality

According to the data sheet, the Galaxy S20 Ultra has significantly more power behind the display. The eight cores of the Exynos 990 are clocked at up to 2.73 gigahertz and have 12 gigabytes of RAM at their side. The eight cores of the Exynos 9611 in the Galaxy A51, on the other hand, have to make do with 4 gigabytes of RAM and reach a maximum of 2.31 GHz.

The theoretical performance difference then manifests itself in benchmark tests:

The figures show that the hardware of the Galaxy S20 Ultra is roughly 2.5 times as powerful as that of the A51. But what does that mean in everyday use? If - apart from exceptions such as Fortnite - the same apps are running on both smartphones, the charging time is a decisive factor. Do you need more patience with the A51 or do you even miss out on photo opportunities? I tested this by opening Google Maps, the camera, the Play Store and PUBG Mobile as examples.

The simplified figures show that the Galaxy S20 Ultra is faster. However, the difference is not so massive that the A51 is unusable. It just seems slow if you have already got used to the speed of a top model.

5G, battery and headphone jack

There are other features that justify the higher price of the Galaxy S20 Ultra, but don't necessarily make it a better smartphone. For example, you can already use 5G with Samsung's top smartphone - if your contract and the radio masts in your area allow it - and the A51 only offers 4G. The S20 Ultra is IP68-certified for dust and water resistance. On the A51, you can still connect headphones via cable to the 3.5 mm jack.

The larger battery of the S20 Ultra - 5000 mAh vs. 4000 mAh - does not provide a significantly longer battery life. In view of the larger display and the more powerful hardware, it is necessary to achieve a similar operating time. The internal memory of both smartphones is 128 gigabytes. There is a difference in the maximum expandability with a microSD card. The A51 can handle up to 512 gigabytes, the S20 Ultra up to 1 terabyte.

Better yes, but worth the price

The Galaxy S20 Ultra is better than the Galaxy A51. Clearly in some criteria, less clearly in others. The camera at night speaks for itself, but you have to look very closely at the display. The S20 Ultra, on the other hand, can hardly "bring the extra performance to the road".

After trying out both smartphones, I think it's okay that the Galaxy S20 Ultra is more expensive. However, paying almost four times as much (as of 26 June 2020) as for the Galaxy A51 is hard to justify to my inner piggy bank. <p