The Nokia 8 leaked image shows a Zeiss brand name on the back, where the rear camera is. This suggests that the Nokia 8 will come withe a Zeiss branded optics. When it comes to Nokia brand, people are really excited about the brand because it's name is synonymous to great user experience, great design and great camera. Many users have nostalgic memories of some of Nokia's most iconic phone like the Nokia 5110 (1998), Nokia 3310 (2000), Nokia 6310 (2002) and others.
Furthermore, people also remember Nokia's popular Windows Phone based smartphones, and especially the amazing cameras they brought with them. We all remember the Nokia Lumia 1020 (2013) which came with a staggering 41MP PureView camera with pixel-binning technology and a Xenon flash. Many of us remember the 808 PureView that stunned us with its large sensor aand amazing image quality. Those phones and others used Carl Zeiss optics.
By the way, if you didn't know, Carl Zeiss dropped the 'Carl' word and became 'ZEISS'. So any future produce, lens or whatever Zeiss made, will be used with a ZEISS brand.
So why so many people are excited about having Zeiss optics in the Nokia 8? In three words: "Great optical performance". Zeiss, which is a German manufacturer of optical systems, is known also for its premium interchangeable lenses for digital cameras. Zeiss produce both the high-quality lenses and construct premium lenses for professional photographers. Their workmanship quality is second to none. Their camera lenses are used for SLR/DSLR cameras, as well as for cinematography and automated imaging machines.
Zeiss expanded its business into the smartphone photography. I don't know which exact year it entered the smartphone business, but browsing through Wikipedia, I can see phones like the Nokia 6220 Classic (2008), the Nokia 6260 Slide, the Nokia 6500 Slide; all camera with Carl Zeiss optics.
For smartphone users, the Zeiss brand become synonymous for high image quality once Nokia incorporated Zeiss optics in its Lumia phones. Windows Phone failed and Nokia found itself losing very large market share. Nokia and Zeiss brand now unite again to bring the Zeiss brand into future Nokia-branded Android phones.
Zeiss lenses are superior to other optics used in most phones nowadays. A Zeiss lens mobile phone camera can lead to a better image quality across the board due to better lens construction and better light transitivity. We can expect better sharpness in the corners of the frame, better color fidelity, better contrast and less distortions. How well it performs is entirely depends on the type of lens used. No doubt that Zeiss optimized the lens for that particular phone and I have no doubt that it will be a custom-made setup that we haven't seen before. The reason for that is because I assume a flagship sensor is used and the lenses has to be optimized for that particular sensor. I also assume that Nokia won't cut corners and aim as high as possible to satisfy the expectations of its loyal customers.
The Zeiss brand optics are one of the main reasons I am keeping a close eye on the upcoming Nokia 8.