HTC has been doing unique things with the cameras on their smartphones for a long time now, but none have been quite as controversial as the Ultrapixel cameras that grace the back of the 2013 HTC One M7 and 2014 One M8. These cameras were called Ultrapixel because the physical size of the pixels on the sensor were much larger than others on the market, so while most camera sensors on the market use anywhere from 1.1 to 1.5 micron large pixels, HTC's Ultrapixel camera used relatively massive 2 micron pixels to illuminate the sensor. This allowed for more light to be let onto the sensor, which in turn increased the overall low light usability and made it quite possibly the best low light camera on the market. This large pixel size comes at a cost however, as HTC had to lower the resolution in order to physically fit such a large sensor within the sleek metal body of the HTC One.
With 2015's HTC One M9 it's been apparent for some time now that HTC has been toying with the idea of ditching the Ultrapixel camera as the rear camera and placing it on the front. Now that we're nearly certain that's true thanks to promotional videos leaked yesterday, we also know the 20MP sensor on the back of the One M9 is also true. Where HTC is differing from competitors isn't just by offering a higher megapixel count than others out there, but by choosing a brand new sensor that hasn't been in any smartphone to date. This is presumably Toshiba's T4KA7 sensor which was announced in August 2014 and features a number of unique traits that could help it lead the pack of smartphone cameras.
By not using a Sony sensor HTC is once again skirting the pack and trying to make a name for themselves in the camera space. While Sony sensors are generally thought of to be the best in the market there is always room for competition, and it looks like Toshiba may just be bringing their A-game here with the T4KA7. Besides being a 1/2.3" size sensor with 1.12 micron pixels, the T4KA7 features a proprietary square pixel design. While Toshiba uses marketing speak to discuss the advantages of this pixel layout we're going to need to wait for real-world results to see the difference here. The rest of the bullet points on the spec page show industry standard imaging tricks like instant HDR, 1080p 90FPS video and more. HTC is clearly not satisfied with just using the same sensors as the competition, so it will certainly be interesting to see how this plays out this Sunday when HTC officially announces the phone at Mobile World Congress 2015.