You asked
Is the pentax k s2 good in low light?
Here is what the site says about that.
From Pentax K-S2: Pentax K-S2: A DSLR by Pentax with a 20.1-megapixel APS-C sensor, announced in 2015. Small and weather-sealed, with a flip-out screen. Specs - Maker: Pentax - Mount: Pentax K - Sensor: APS-C, 23.5 x 15.6mm, crop factor 1.5 - Resolution: 20.1 megapixels - Stabilisation: in the body - Announced: 2015 - Type: DSLR Focal lengths on it Lenses frame like 1.5 times their focal length on full frame: 16mm like 24mm, 23mm ...
From Sensor sizes: Is full frame worth it?: For low light, events, and portraits with very shallow depth of field, yes. For travel, street, wildlife on a budget, and most hobby photography, a good APS-C camera with good lenses is enough, and you'll carry it more. Lenses and light matter more than the last stop of sensor performance.
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