A few days ago, Sony has revealed they will announce a new device with a very fast camera on August 3rd. However, there is no further information about this upcoming device at the moment.
Today, the website hi-tech.mail.ru has published a preview post about both Xperia M5 and C5 Ultra, including full photos.
Sony Xperia M5
As you can see in the picture, the Sony Xperia M5 looks like the middle range Xperia Z3+ smartphone, sports a 5-inch 1080p Full HD IPS display and powered by a 2GHz octa-core MediaTek Helio X10 SoC.
It has a 3GB of RAM, a 16GB of internal storage, a 21.5-megapixel main camera (Exmor RS IMX230 CMOS sensor; f/2.2 and fast auto focusing), a 13-megapixel selfie camera, a 2,600 mAh battery, IP65/IP68 certificate and supports MicroSD card. The Sony Xperia M5 will be available for around $400, a dual SIM variant will also be available.
Sony Xperia C5 Ultra
The Sony Xperia C5 Ultra has a larger display than the M5: a 6-inch 1080p Full HD display, and powered by a 1.7GHz octa-core MediaTek MT6752 SoC with 2GB of RAM and 16GB of internal storage, expandable via MicroSD card slot.
Other specifications I have about the C5 Ultral are supports NFC and dual SIM cards, will be available for about $350.