If you are keen to step away from the Canon and Nikon fold, or perhaps you have a lot of Pentax legacy lenses, then the K-S1 seems like quite an appealing prospect on paper. It's easy to see why the company goes for all the gimmicks of different colours and flashing lights when it has to compete against the behemoths of the others in the industry, but at the same time, this can make what is otherwise a decent camera feel a little cheap and tacky.
However, if you like that kind of thing, and we can only assume that there must be plenty of people who do, then the K-S1 could be a good investment.
It's a rather boxy design, but using the camera is easy enough, if a little slow in some places (such as having to switch between using the directional keys by holding down the central OK button) – but you get used to how it works reasonably quickly.
Image quality is good, and low light shooting is particularly impressive, with barely any noise apparent in JPEG images shot at ISO 3200 and ISO 6400. There's also the universal DNG raw format which means you can use whichever photo editor you like without having to wait for compatibility updates and so on – always handy.
There's a decent range of effects, so if creativity is your thing, this is another reason to choose the Pentax over Nikon and Canon cameras, which don't have anywhere near the number of digital filters on offer here. You can shoot them in raw format too, so you don't have to worry about being stuck with a filter you don't like later on.
The screen and viewfinder are good - and it's nice to see a 100% viewfinder on a camera at this level. It's a shame that the screen is neither tilting, articulating or touch sensitive, but this may have bumped up the price a bit - and at the moment it represents good value for money compared with its closest rivals.
Image quality is the best thing about this camera, and of course that's arguably the most important thing. Images are bright and punchy directly from the camera, while the quality in low light is particularly impressive. Detail is resolved well by the anti-aliasing filterless sensor, too.
It's really time that Pentax did something about its standard kit lens. It's noisy, hunts around for focus and there are much better examples on the market. If you're buying this camera then be prepared to invest additional money in a different lens to get the most from it.
Overall, this camera is a decent purchase for people who are looking for their first DSLR. Some will be put off by the design choices on offer here from Pentax, while others will welcome them – if you buy from a camera shop you can handle the camera first to see what you think.
Factor in some budget for replacing the kit lens and you'll no doubt be pretty happy with the camera, but if you can't do that, then you're probably better looking at the alternatives from Canon or Nikon, which come with much better kit lenses.
Good image quality and reasonable handling, however, make the Pentax K-S1 appealing if you already have some Pentax gear.