HTC One’s UltraPixel camera vs the competition

HTC One

HTC’s latest flagship “One” aks M7 has 4MP ultrapixel camera. HTC aims to end the megapixel race by providing consumers with better image quality rather than just numbers. Looking at Android smartphone cameras, there has been very little improvement in image quality. Phones are getting anorexic and engineers are forced to pack more megapixels while sensor size continue to go down. HTC’s approach is different and appreciable. We will compare HTC One with some of the best cameraphones like Nokia Lumia 920, PureView 808 and Samsung Galaxy S3. I wont give any final judgement as real world performance matters more than numbers.

 

Sensor Size/Pixel Size

Sensor size and more importantly Pixel size is the single most important factor determining image quality (IQ) of the camera. Sensor Pixel is the unit or photosite capturing light. Bigger pixel size allows camera to gather more light. Another advantage is less “leakage” of current between adjacent pixels. Pixel size determine the sharpness, noise levels, low light/high ISO performance and dynamic range, ultimately contributing to image quality

HTC One has a 1/3” sensor with a 2 micron pixel size. Lumia 920 and Samsung Galaxy S3 have similar sensors but with a pixel size of 1.4 micron each. Nokia 808 has 1/1.2 inch sensor with a pixel size of 1.4 microns. 5MP oversampled output (7 pixels combined to make one pure pixel) in conventional terms will have a pixel size of approximately 4 microns

HTC may have managed to increase the pixel size by decreasing megapixel count. However  1/3″ is still tiny and it won’t be able to produce appreciable shallow depth of field (popularly known as bokeh)  like the 808

 

Resolution

Resolution determines the details captured by a camera. More megapixels however don’t necessarily mean better details. For example I found the 13MP images from Xperia Z to have lesser details than 8MP output from Galaxy S3. Similarly a 5MP image from Nokia 808 packs more details than any 8 or 13MP smartphone. This is because of difference in lens optics, sensor size, aperture size, image stabilization and image processing. Actual resolution depends on a lot of things. But if you are still interested. HTC One has a 4MP sensor compared to 8MP on Lumia 920 and S3 and 38MP on Nokia 808 (5MP non Bayer output in Auto mode)

HTC has definitely taken a bold move here. Most 2013 flagships will still have 13MP sensor. However OEM’s will soon be forced to quit the megapixel race. Even if you put a bigger sensor to improve IQ, more megapixel still mean larger image size.  4-5MB images are not very ideal for uploading, especially when LTE is still US only and 3G is very costly in countries like India.

Sensor technology

Nokia 808 has a CMOS sensor while other three contenders including HTC One have a Backlit CMOS sensor. Backlit CMOS captures more light than traditional sensors if sensor size is same. Talking about numbers, a 1.4 micron BSI CMOS pixel captures the same amount of light and has the same Signal to Noise ratio as 1.75 micron pixel traditional CMOS

Sensor technology has vastly improved over the years. So HTC’s flagship will undoubtedly have much better IQ, dynamic range and sharpness than Nokia N95 despite having similar pixel size.

Optics and Aperture

HTC One and Lumia 920 share f/2.0 aperture which is quite wide. Samsung galaxy S3 has a 1/2.6 lens while Nokia 808 uses a 1/2.4 lens. Larger aperture allows more light to reach the sensor. Both Nokias also have Carl Zeiss optics.

 

Image stabilization

Image stabilization reduces blur caused by tiny camera movements. It also allows camera to gather more light by keeping the shutter open for a longer duration. HTC One has gyroscope based 2 axis optical image stabilization (similar to lens shift stabilization). This will reduce the blur in horizontal and vertical axes.

Lumia 920 has a 5 axis barrel shift (sensor shift) stabilization. This is a highly advanced OIS system and reduces blur caused by rotatory movements in all three directions apart from balancing linear movements in horizontal and vertical axes.

Nokia 808 and Galaxy S3 have digital stabilization (much inferior than optical)

 

Video

All 4 contenders can capture 1080p at 30fps (not bad tbh). Nokia Pureview also has lossless zooming. All cameras have continuous AF.

HTC One also features HDR video and 768×432 video @ 96fps and 720p @60fps

Both Nokia use 2 mics for Rich Recording (SPL = 140dB). HTC One also has 2 mics for audio recording but they haven’t specified any SPL.

 

Conclusion

HTC’s only problem is the 4MP resolution. Despite the large pixel sensor size, noise will be present in images with ISO greater than 400. 100% crops will not look as good as 808 PureView’s 5MP output. You cant really compare the detail of a 5MP  output from Pureview and 4MP from HTC  One because due to oversampling 808 has a lot of advantage.

In daylight I don’t think HTC One will be anything special. Its dynamic range should be very good but as far as image details are concerned, all three cameras will perform better.

In low light, HTC one should really shine. It wont beat 808 by any means but should perform better than Lumia (which in my opinion over exposes and produces bright but noisy images) and SGS3.