S20+ Tele Image Resolution is Fake - Only a 1X Optical Lens!

[consultant]

Okay, I understand (what many others don't) that although the S20+ is listed as a 3X-30X zoom, the actual optical zoom is 1.08 so the focal length of the actual lens is basically the same as the non-zoom camera. This is unlike say the S10 5G which the actual lens of the camera is 2X. However Samsung makes up for this by using a 64MP sensor. This basically results in as good or better zoom shots up to about 5X zoom than a phone with a tele-camera with a 2X or 3X optical zoom lens but only a 12MP or 16MP sensor.

This is a bit astonishing considering the number of pixels decreased by the zoom factor squared when using digital zoom. So, the lowest zoom of the tele lens on the S20+ at 3X is essentially a 7MP sensor. 3 squared is 9. 64MP divided by 9 is 7.1MP. Compared to say the S10 5G which has a 2X optical zoom and 12MP sensor. So a 3X zoom for the S10 5G is a 1.5X digital zoom of the 2X optical. 1.5 squared = 2.25. 12MP/2.25 = 5.3MP. So you can see how the S20+ can keep up with other cameras with 2X or 3X optical zoom but only 12MP sensors. It's notable though that with 2X zoom, a camera with a 12MP sensor and a 2X optical zoom has a higher resolution image than the S20+ at 2X zoom since the S20+ doesn't have an optical zoom lens.

What's more interesting is the 64MP sensor on the S20+ has a 0.8um pixel pitch which means the sensor is roughly 9,500 pixels by 7,150. So at 3X zoom the sensor output is going to be digitally cropped to around 3,160 x 2,380. However no matter what zoom resolution you use, Samsung outputs a 4032x3024 size image, basically "faking" the resolution for all images taken at anything over 1X zoom. The file size goes down as the zoom goes up even though the image resolution stays at 4032x3024 because the JPEG compression algorithm basically can see it's a fake resolution (essentially a lower resolution source image interpolated up to a higher resolution.)

I'm not sure why manufacturers do this except for only from a customer satisfaction perspective as people would be complaining why their 10X zoom images are only 950 x 715 pixels. Yes, S20+ users, that is roughly the true resolution of a 10X zoom image from your phone. But consider on a 12MP sensor with 1X optical lens, that true cropped resolution is closer to 400x300!

The bottom line is the S20+ Tele Camera is basically equivalent in resolution to a phone with a 12MP camera with a 2.5X optical zoom because it's not actually an optical zoom lens. So Samsung's advertising it as a 3X "hybrid optic zoom" isn't a total lie, but 2.5x would be closer to accurate as far as the equivalent of an optical zoom on a 12MP sensor.

In reviewing tests images, to get the best images on this camera you just want to use one of the 3 cameras without manually zooming in. If you do zoom in on the tele camera, try to not go above 5X.

 

[Hadron]

OhGod I'm confused, so which phone has the best camera in the end?

The one whose pictures you like best.

That's not a joke or a glib answer. I personally dislike over-saturated colours, smearing to eliminate any trace of noise and excessive sharpening to create a false impression of detail. So whenever a reviewer praises a camera for producing images that "pop" I know that I don't want that camera. But others like bright, vibrant images even if they aren't as realistic a record of what you actually saw. People have different tastes in these things, and the "best" camera for you is the one whose images you like, which may not be the same one that I prefer.

There's no substitute for looking at the actual images taken by a phone and deciding whether you like them. Other people's opinions, or junk marketing tools like DxO ratings (a collection of metrics combined with an arbitrary and changing weighting to give a pretense of objectivity), are not good ways of deciding this.

As for the S20+, yes, "digital zoom" is always as described: crop then scale up. Same on any phone and even pocket cameras that have such a feature. And the deceptive marketing description of the S20+'s "hybrid optical zoom" was flagged up in reviews (e.g. GSMArena called it "a bit deceitful") and subject to some discussion at the time. But unless someone raises a formal complaint with the regulator in your country that results in them having to withdraw this description most people will just take the marketing claim at face value.

 

[consultant]

The website DXOMark is considered the authority on evaluating digital cameras including the ones in phones and assigns them a score. The best phone cameras are in the flagship phones of the Chinese brands but unfortunately those phones can't use the Google Play Store due to U.S. regulations which is a deal breaker for many people (including myself). Basically the iPhone 12 Max Pro has the best cameras and then for Android, the Samsung S20 ULTRA has the best. You can see some comparison photos in their review. The Ultra is more expensive, bigger and heavier, and some users have had some autofocus issues. But those are "the best" right now disregarding your budget. The Ultra has an actual 3X optical zoom lens not a fake 3X digital zoom like the plus. Combined with a 108MP instead of 64MP sensor makes it's zoom capability superb. the 100X zoom is a joke though. All these phone cameras the zoom is really only usable up to about 1/3 their zoom range as the photos look like crap beyond that.

Why Samsung didn't put the 2X optical zoom lens in the plus from the S10 5G and then use the 3X optical on the Ultra is just beyond me but my guess is they wanted to create a bigger difference in specs to justify the higher price of the Ultra. Even crazier is they put the same 3X optical lens on the S20 FE as the Ultra! Although the FE is only an 8MP sensor, if you find comparison reviews you'll see the FE zoom images are slightly better than the plus. They essentially tied one hand behind the S20 Plus's back by using the 1.08X optical lens on the zoom camera instead of the 3X lens they used on the FE and Ultra.


https://www.dxomark.com/samsung-galaxy-s20plus-camera-review/

 

[Hadron]

It's funny how you post that just after I say why I don't respect DxO scores . Many of the individual tests that go into their scores are fine (though there are questions you could ask about some of them), but the overall score they give is worth very little, since that relies on an at best subjective (I'd personally say arbitrary) combination of those constituents. And of course they work with and take money from manufacturers on these scores, which is another reason for scepticism.

I stand by my answer: look at samples, decide what you like, ignore marketing BS.

 

[consultant]

I don't take the DXO Scores as the Bible of Camera ratings, but I find it useful as an information source for relative comparisons between devices. A lot of phone users, especially the younger generation, tends to get very caught up in spec numbers and ratings. Very few people actually fork out $1000 for a new phone. They just pay their monthly fee to cover their service and phone payment and pay $1500 for the phone over 2 years.

These same people might take a DXO score of 120 compared to 116 as an indication the 120 phone is significantly superior to justify in their mind the reason they should upgrade, when in reality the average user wouldn't tell any difference. It reminds me when digital camera sensors started advertising more and more megapixels. The buyer going into Best Buy gravitated towards the camera with more MP, "more is better" is the general way people think and the manufacturers gear their designs and marketing towards that. Later, people digging deeper come to find out, in most cases, more megapixels = more noise. The latest marketing spec hype is the 120hz screen refresh rate in phones and the talk that "oh no, the new iPhone is still only 60hz!" And you go onto YouTube and find all these comparison videos where they have to show the comparison with the video shot at 120fps and slowed down to 1/4 the normal speed to see the difference and talk about how much more "buttery smooth" the phone is! (Umm reality doesn't happen at 1/4 speed.) In most cases, the user would be happier if they left the phone at 60Hz and gained an extra hour of battery life. LOL. But 120hz sounds better than 60hz. More is better.