Family resemblance...

When Pentax jumped into the mirrorless interchangeable lens camera craze in 2011, it's pretty obvious from where they drew their styling inspiration.

The Pentax Auto 110 of the late-'70s and early-'80s was pimped as the tiniest interchangeable lens SLR on the market, using the little 110 Instamatic film cartridges Kodak had introduced in '72.

Pentax marketed the Q-series digitals the same way. Ironically, the teeny 110 film negatives are the same size as a Micro 4/3 image sensor, which is much larger than the little 1/2.3" sensor chosen for the initial Q models. (The later Q7 and Q-S1 had slightly larger 1/1.7" sensors.)

From Wikipedia.

The small sensors are going to cause problems with noise at higher ISOs...

click to embiggenate

The above image is using the 3.2mm f/5.6 03 fisheye lens on the Q-S1, which has the later, larger sensor. It's a 1/6th second exposure at ISO 3200 and is obviously noisy as dammit.

Despite being an interchangeable lens camera, the Q-S1 uses the same 1/1.7" sensor size as my late, lamented Coolpix P7000, a higher-end compact. (The original Q and the Q10 use a smaller sensor, the same size as the one in the old Canon ShowerPot SX500 I've since handed off to Bobbi.)
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Sensor Sweep...

The Nikon Coolpix S6500 I used for a year or so back in 2014-'15 is on the left, with the Pentax Q10 on the right.

The Q10 is the second iteration of the series, being a more value-priced proposition than the original Q, largely by replacing the magnesium shell of the original with a plastic one. It debuted in September of 2012 and featured a 12MP 1/2.3" sensor...

A digression to mention that digital camera sensor size descriptions date back to the earliest days of digital video. A 1/2.3" sensor is 6.17mm across by 4.55mm tall, or 7.66mm across the diagonal.

The Nikon, which hit the market in January of 2013, has a sensor with the same physical dimensions, but 16MP resolution. The lens on the Coolpix is the equivalent of a 25-300mm zoom, in 35mm terms, but only an f/3.1-6.5. Consequently the Coolpix tends to be noisy at longer focal lengths in anything but the best of lighting conditions.

With a wider choice of bigger, specialized lenses, and the ability to shoot in RAW for better image processing, the Pentax Q10 ekes a lot of performance out of the little 1/2.3" sensor by comparison...but it's still a tiny sensor. Noise is going to happen at higher ISOs no matter what trickery you employ.