Image Quality & Performance

The OnePlus 3T combines a top-end processor with 6GB RAM, so it's no surprise overall operation is very swift, making the OnePlus a smartphone that is a pleasure to use in all situations. The camera app takes under a second to start and reacts swiftly to any input, without delay. In good light the AF is very fast, at close to 0.5 seconds. It slows down noticeably in lower light but usually still manages to lock focus within a second or so. Only low-contrast targets can lead to a little bit of focus-pumping, usually well within acceptable limits.

The battery is one of the device's strong points. Not only does it provide very decent battery life – we'd usually get at least 1.5 days of normal use out of it – it also charges very quickly. That is especially true when using the included DASH charger and cable which can get you from an empty battery to a 60% charge in just 30 minutes. That said, I was mostly charging the phone with just a standard USB Type-C cable which also works faster on the OnePlus than most other devices I have recently tested.

Daylight, Low ISO

In good light the OnePlus 3T camera offers very good image quality but is not quite up with the very best in class. Sharpness is good in central areas of the frame but the lens of our test unit showed some noticeable softness towards the left edge of the frame and in the corners. 

If you view images at a 100% magnification you'll see that higher contrast edges are very well defined but fine low-contrast detail is affected by a mix of strong sharpening and noise reduction, resulting in textures that look more processed than the best in class. There is also some visible luminance noise in areas of plain color, like the blue sky in the first sample below. 

Like many smartphone cameras, the OnePlus 3T is prone to clipping highlights in high-contrast situations. It's not any worse than many of its direct rivals but not as good as on devices that use sophisticated multi-frame modes to combat the problem, such as the Google Pixel with its HDR+ mode or the iPhone 7 Plus. 

 ISO 100, 1/928 sec

Colors are typically slightly on the warm side with strong saturation and contrast. This can lead to pleasant results as in the image below, but if you prefer things a little more natural your only option is shooting and converting DNG Raw files. 

 ISO 100, 1/245 sec

For reasons that are not quite clear the camera occasionally increases ISO to 125 when shooting in bright light but there is no visible difference to base ISO images in terms of pixel-level detail or noise. In natural light, skin tones tend to be pleasantly warm but can occasionally be a little too saturated.

 ISO 125, 1/1593 sec

The OnePlus 3T deals well with strong light sources and lens flare is hardly ever an issue. Chromatic aberrations are very well controlled as well. The sample below shows noticeable noise in the shadow areas, though.

 ISO 100, 1/1668 sec

The camera is still capable of capturing decent detail and keeping noise levels at acceptable levels in overcast situations. However, lens softness towards the left edge of the frame is again quite apparent in the sample shot below. 

 ISO 125, 1/100 sec

Low light, high ISO

In lower light the OnePlus 3T camera manages to capture good color and exposure down to very low light levels. In auto mode shutter speeds go down to a minimum of 1/17 sec and while the optical image stabilization is generally doing a decent job we've found slight softness in a higher proportion of images than usual with OIS-equipped devices.

For the winter outdoor shot below the camera increased ISO to 200. Exposure is fine and the skin tones pleasantly natural. Compared to the bright light shots, fine detail is already starting to suffer a little, which in this shot is exacerbated by just a touch of softness caused by subject motion. Noise is very well under control.  

 ISO 200, 1/33 sec

In well lit interiors, like in the ISO 400 shot below, the camera is capable of maintaining good detail. Some luminance noise is becoming visible in the mid-tones but it is pleasantly fine-grained and not intrusive at all. Chroma noise is very well under control.

 ISO 400, 1/20 sec

In lower light the white balance system usually does a decent job at balancing artificial light sources. The ISO 500 image below again shows well-defined edges and finely grained luminance noise, maintaining good detail for the light levels. 

 ISO 500, 1/20 sec

At ISO 800 and higher the camera cranks up noise reduction which results in a slightly softer appearance at pixel-level. In the ISO 1000 shot below edge detail and fine detail have decreased, compared to the previous samples, but are still very acceptable. On the plus side, noise is very controlled. 

 ISO 1000, 1/17 sec

For the night show below the camera increased ISO to 2500. In the shadow areas noise is much more visible now and forming into more intrusive "blobs". However, the illuminated areas still show good edge definition and  pretty noise-free. Overall, this is still nice to look at on a larger screen. 

 ISO 2500, 1/17 sec

The last sample below was captured in the very dimly lit interior of a cathedral. In these extreme conditions the camera is pushing ISO all the way to 6400. At a 100% view the image is noticeably softer now and smeared luminance noise is clearly visible. However, chroma noise is very well controlled and the image shows good exposure and color. Overall, the OnePlus is performing well in these very low light levels. 

 ISO 6400, 1/17 sec

We've already had a closer look at the 3T's HQ mode on the features page. Below are a couple more samples to show what the mode can do. HQ images in low light tend to be cleaner, with more finely grained noise, than standard exposures. They also show slightly better textures and fine detail. Dark shadow areas tend to get lifted to a small degree. Overall, the mode is well worth using in low light, despite a slight processing delay.

 ISO 640, 1/17 sec, HQ on
 ISO 2000, 1/17 sec, HQ on

Flash

The OnePlus 3T comes with a dual-tone LED flash that is capable of capturing a decent shot at close subject distance in low light. The sample below shows well-exposed skin tones while maintaining some of the darker Christmas atmosphere in the background. At ISO 800 image detail is still decent and noise well under control. 

 ISO 800, 1/20 sec, flash on

At a larger subject distance in flash mode the camera tends to expose more for the background which can result in slightly underexposed subjects. That said, for this particular scene the approach works reasonably well.

 ISO 400, 1/25 sec, flash on