It always bugs me when companies tout their new smart phones, using marketing phrases like “ultra sharp 4K recording quality”. In reality “4k” image quality can vary a LOT. To demonstrate this, I compared footage taken from my Sony A6600 DSLR camera, my Samsung S20 smartphone and an Annke PoE CCTV camera.
This video also drills into exactly WHY image quality varies so much, even when all three devices produce videos that are 3840 x 2160 pixels:
In short, the camera’s sensor and also recording bitrate matter a lot. My Sony camera’s sensor has a substantially bigger sensor size than the other two devices, for example, and this is clear from my 3x footage tests.
I also discuss why FPS and night vision modes can be important for recording quality.
If you prefer text over video, please read on for the guide/transcript version of this video.
Video Transcript And Guide
Hey everyone, “4k” is meaningless. It’s a myth. An illusion. A con. I mean, TECHNICALLY it’s not – it refers to something that is 3840 pixels wide by 2160 pixels tall. BUT there’s a problem with this definition. THIS is a 4K image. It’s 3840 pixels wide, after all. HOWEVER all I actually did was take footage from a budget full HD camera, and BLOW it up to 4K. The actual “4k image quality” here is useless, because you can barely see any details on my face.
THAT’s the concern I have when companies go out and market “4k cameras” – be it on webcams, smart phones or CCTV cameras. What ACTUALLY matters for image quality is the camera sensor and BITRATE of the recording. I mean, technically there IS more to it as this super smart guy pointed out on Reddit:
But in general, the sensor and bitrate are what matters for the average joe – or average Tristan, in this case!
Annke vs Samsung S20 vs Sony DSLR
To highlight this point, I took footage from my garage’s 4k camera from Annke:
I compared this with my Samsung S20 phone and also my Sony Alpha DSLR camera:
My Annke records in 4K resolution with 3 and a half megabits per second bitrate (it actually supports up to 6 megabits, but it averages out closer to 3 and a half):
My Sony camera is recording at 56 megabits per second bitrate, while my phone records at 40 megabits.
I did a few tests here. The first one is me leaving the garage door open and this confused my Sony camera – partly because I left it in auto mode, so the backlight then flooded the scene and meant my face was barely recognisable… which isn’t ideal. But IN GENERAL when you do try and pick out some detail like this box of screws that I’m holding up, the Sony camera is MUCH better than the Annke and Samsung devices:
The detail and quality varies a lot here despite all three recordings are being marked as “4k”. My Annke CCTV camera and Samsung phone often result in SIMILAR image quality, maybe with my phone being SLIGHTLY ahead – but not enough to justify 11 times more bitrate. In other words, my phone’s recordings take up a LOT more disk space than the Annke camera:
Second Garage Test
While that first test didn’t show my Sony in the best light (get it? Light – the backlight caused an issue, yeah? nevermind), that was mainly down to me leaving my Sony in “auto” mode which caused y’know those backlighting problems that we saw. My second test was “fairer” and it involved shutting the garage door and turning the light on, and you can see that the Sony camera is massively ahead of the Annke and Samsung devices here:
My face is CLEAR almost all the time with the Sony, and the box of screws is also readable further away and also close up. Comparing the Annke and Samsung devices, I THINK I prefer the Annke image quality here – my face and the screw box both lack clarity with the Samsung device in my opinion.
BUT what do you think? Please let me know your thoughts down in the comments because this can all be a bit subjective.
A Point About Night Vision
Before discussing the reasons WHY the image quality varies so much between these three “4k” recordings, I wanted to make two quick points. Firstly my Sony and Samsung cameras don’t really offer “night vision” recording, while my Annke CCTV camera DOES. This means that when I turn the light off, my Sony and Samsung devices are as useful as a screen door on a submarine:
I like that one. When the Annke cam detects low light, it switches on its infrared lights which you can hear by the clicking sound. It then records me in DECENT quality considering that it’s almost pitch black in the garage:
So if you are looking at 4k cameras and you wanted to sometimes record in the “zero light” situations, make sure that the device has some night-time support – like a conventional CCTV camera, or pairing a fast lens with a full-frame camera.
When FPS Is Important
My second “quick point” is that I realize I haven’t discussed FPS yet. My Sony and Samsung cameras are recording at 30 FPS, although they DO support 60 FPS at 4K too. However my Annke camera is stuck at 15 FPS. This isn’t too bad for conventional security cameras, however if you plan on recording roads (in other words, moving cars), then 15 FPS probably won’t be enough to capture the motion properly. You’ll often end up with blurry stills and insufficient detail – such as not being able to read the plate number.
Why Sensor Size And Bitrate Matter Most
Okay, so I’ve compared these three “4k” cameras and it’s clear that the image quality can vary a LOT. Having too much light – or none of it – can make a BIG difference. But in ‘normal’ conditions, my DSLR camera is significantly better than my phone and Annke cameras. Why is this? Well, as I mentioned earlier, both the camera’s sensor and storage bitrate matter a lot. A camera’s sensor is the thing that captures incoming light. A large sensor means that more “information” can be captured, resulting in higher image quality, less noise and often just better performance in low-light situations (although as we saw, they can’t work miracles if there’s just zero light),
The size of the three sensors are below:
|Sony A6600 (DSLR)
|Samsung S20 5G FE (Phone)
|Annke C800 (PoE CCTV Cam)
You can see that the Samsung and Annke ones are SIMILAR, but the Sony is far ahead. It’s much bigger, meaning that it can capture more light and ultimately deliver higher quality images:
And that’s pretty much what we saw from our tests, too, with the Samsung and Annke being close to each-other but the Sony being far ahead.
THAT’s why the sensor is so important, and when a new camera or phone is released and they just discuss it as “4k” or “120fps at 4k”, I’m never too interested. If the sensor is small – like on my Samsung’s – then they can use all the fancy marketing terms they want, BUT in reality, the image quality will be closer to a 2k camera. That’s why I started this video by saying that “4k” is meaningless.
But what about bitrate? Well this is literally the number of bits per second that gets stored:
The higher the bitrate, the higher the image quality – IN GENERAL. There is a case of diminishing returns here though. You know how you can compress a large 10 megabyte file down to 1 megabyte and the pictures almost look the same? Well you can do SIMILAR with video recordings too. I could probably get my 56 megabit Sony recordings down to 20 megabits or so, without losing much image quality.
That’s also why my Samsung and Annke cameras have similar quality despite having VERY different bitrates. My Samsung phone lazily records at 40 megabits, even though its camera sensor is too small to justify such a high bitrate. In other words, my phone’s recordings take up too much space considering that the image quality is often lacking at 4k level.
And that pretty much wraps up today’s video. I know this is a “tech” channel not a camera review channel, but I wanted to drill into this topic because most of us ARE interested in “4k”, image quality and often cameras. I hope you enjoyed this video. If you did, please click the thumbs up button. Please also subscribe to my channel if you haven’t already and thank you for watching!