The Pentax K-S1 is a mid-sized DSLR camera announced by Ricoh on August 27, 2014. It features a 20 megapixel sensor - new to Pentax' line-up - and an anti-aliasing filter simulator as previously seen in the Pentax K-3.
Also adopted from the K-3 is compatibility with the Pentax FluCard, which allows wireless tethered shooting and wireless download of images from the camera.
In other respects, the K-S1 inherits a fair amount from the K-30/K-50 lineage, such as the compact, 100% coverage viewfinder, 1/6000s shutter and D-LI109 battery. A stereo microphone is also built in, to complement the FullHD video capability (30 frames per second (30p)).
It has been noted that the K-S1 is insignificantly larger than the Canon EOS 100D, which as of August 2014 is still the smallest DSLR in production.