The Redmi Note 9S has one square bump at the back that houses all four cameras. The arrangement is familiar, in fact, it is the same as on the Redmi Note 8T - first is the ultrawide snapper, then the primary one, the depth camera is next, and last is the macro shooter.
The main camera uses a 48 MP sensor with a Quad-Bayer filter, probably the ISOCELL Bright GM2 sensor by Samsung. It's a large sensor with 0.8µm pixels, and the lens has f/1.79 aperture. The image output is 12MP.
The 119-degree ultrawide-angle camera has an 8MP sensor with an f/2.2 aperture. There is automatic distortion correction applied when necessary, but you can opt-out of it.
Then there's the 5MP macro camera with 1.12µm pixels and lens with f/2.4 aperture. Autofocus is available, which is a rarity among those type of snappers and much appreciated.
The last camera on the back is the 2MP depth sensor.
Switching between modes is like in every other camera app - swiping left and right will take you through all modes while tapping in the upper right corner of the screen where the "hamburger menu" resides will expand the options. The Macro mode was hidden within this menu, which is a bit odd.
The real settings menu is in there as well, and it doesn't offer anything out of the ordinary.
The Redmi Note 9S offers 48MP mode, as well as manual (Pro) one. Speaking of Pro, this one offers pretty much all the settings you'd need - white balance, focus, ISO, and shutter speed. The Pro mode works with the normal camera, the ultra-wide, and the macro. Manual 48MP pictures are also an option.
The 48MP camera saves by default 12MP images, and the ones we shot with the Redmi Note 9S are good for the class. The resolved detail is enough though nothing impressive and that's probably the easiest tell about the budget quality. The foliage is a smudgy mess, the window blinds were too complex for the algorithm and so was any intricate detail.
Still, the photos do offer enough detail, and it gets only better from there - the noise levels are kept low, the contrast is great, and the colors stayed mostly true to life. The dynamic range is pretty wide and the Auto HDR did not fire even once.
The MIUI 11 camera app has this AI Camera trigger on the viewfinder. This option always uses HDR and oversaturates the colors big time. You will see shadows pop unnaturally, and colors go to extremes. But if you like what you are seeing, then it's there for you to use it.
There is a standalone 48MP mode, but what you would does not look like a real 48MP image. The photos seem to be upscaled from the 12MP images and then heavily sharpened. There are no benefits whatsoever when shooting in 48MP, and we don't recommend it.
The viewfinder offers 2X toggle and the photos are exactly what you would expect - digitally zoomed and lacking in detail.
The 8MP cam snaps very good ultrawide photos for this budget class with good detail levels, great contrast and rather high dynamic range. The distortion correction does a nice job around the corners and overall - we are happy with this camera.
The 5MP macro camera shoots great closeups. They are detailed, with little noise and quite lively. The autofocus helps a lot in such occasions as opposed to the fixed focus at 4cm most of the competitors are offering. The colors are a bit dull, but other than that - a remarkable job.
The quality of the portraits taken with the rear camera of the Redmi Note 9S depends on the available light as the resolved detail would drastically drop when the light is not good. So, when the right conditions are met - you will be rewarded with some very nice portrait shots - detailed, with good enough subject separation and convincing faux blur.
The Redmi Note 9S is a good shooter at night even if the images are underexposed. The detail is rather good, left mostly intact by the noise reduction, while the noise itself is kept in order, too. The color saturation is excellent.
The Auto HDR decided to show its presence on some of the scenes (the hotel building), and its aggressive noise reduction smears a lot of the fine detail, while doing little to develop the underexposed areas or restore some blown highlights. Maybe it's not a good idea to use HDR at night at all.
You can trigger the AI mode and get a bit more saturated images at sunset, or sunrise, and we liked these. So, you may want to try it, and see if you like the results in low-light.
The Night Mode is something you should definitely use. You lose some detail, but the gains are huge - balanced exposure and restored highlights, some detail in the shows pop, too. We recommend this Night Mode - it takes less than 2 seconds, but the results are excellent for this class.
The night photos from the ultrawide-angle camera are barely usable. The are lacking in detail, pretty dark, and the smeared noise everywhere is a big party pooper.
There is no Night Mode for the ultrawide camera, unfortunately.
Here's how the primary camera on the Redmi Note 9S stacks against the rest of the competition in a more controlled environment.
The 16MP selfies aren't that sharp and we suspect the imager of having a Quad-Bayer filter. Still, the photos are good, HDR works great when needed, and we observed good colors and contrast. We'd be happy with the native 8MP shots though, just saying.
The selfie portraits offer competent subject isolation and the background blur is convincing.
The Xiaomi Redmi Note 9S captures videos up to 4K @ 30fps, but 1080@60fps and 1080@30fps are available as well.
It seems at first that you can capture in these resolutions with all cameras, but you cannot. The ultrawide-angle and macro snappers record only 1080p clips at 30fps.
Let's talk about the main camera. The video bitrate is 40-42Mbps in 4K and about 20Mbps in 1080p at both 30fps and 60fps. Audio is recorded in stereo with a 96Kbps bitrate.
Despite the high bitrate, the 4K videos have average level, but the quality of the video gets a raise with great colors, contrast, and even dynamic range. The noise is almost non-existent, and maybe an overly aggressive noise reduction is to blame for the loss in detail.
The 1080p clips at 30fps are nicely detailed and among the better ones you can get today.
The 60fps, on the other hand, have the same bitrate as the 30fps, and thus their detail is halved, which is then masked by excessive over-sharpening.
We liked the 1080p videos from the ultrawide camera - they are sharp, with good colors and contrast.
Electronic stabilization is available (in settings) only when shooting in 1080p at 30fps and works on the main and ultrawide cameras. The stabilization does a great job smoothing the camera shake at the expense of minor loss of FoV.
Once you are done with the real-life scenarios, take a look at our video compare tool to see how it competes against other phones.