New camera, or a new lens? Help...

Hello Stephen_H

Your K50 has a similar AF modul like my K5. When you look for a better low light AF, all models after the K5 are better, because they use a 2.8 AF sensor point for the centre AF and for example the KP has three 2.8 AF sensor points.

That makes a big different in low light.

But the advantage of this 2.8 AF sensor points do work only, when you use a f 2.8 lens or faster, else this 2.8 AF sensor points act like on your K50.

So, you need a new camera and a f2.8 lens for a better low light AF.

You got the hint of using a flash.

In short: When you use the flashlight instead the room light, you lost the mood, low light pictures do can have.

But you can use a flash and also include the low light room illumination. This end up in high ISO pictures and therefore, a KP with it's much better IQ for high ISO's will help you very much.

Two low light examples:

That is our Christmas-room, exposed on the light sources.

Now I used two flash (one to the right and one on the camera):

Because I still use the exposure for the natural light sources, my flash picture has still this high ISO, but the mood of the natural light sources and there illumination are still there. I did by the flash only add a light source for to illuminate the parts, the natural light sources did not do.

When you do a pure flash picture, nearly all natural light sources would look's like they was switched off. They would also not show their illuminated areas.

So, you can combine low light pictures with flash light, but you still work for the settings you need for the low light,... in other words, you use high ISO's.

But this way of making pictures a mobile do not offers

This pictures are in B&W, because the IQ (here the colour noise) of the K5 pictures at ISO 5000 does looks not so good in a colour picture. When I had at that time my KP, it would be no problem to do such a picture at ISO 5000 !

So, I would go first for a new camera because of the much better IQ for high ISO low light pictures, than (maybe next year) for a f2.8 zoom lens. Than you get the better low light AF via the f 2.8 AF sensor points of the KP. And, if you will, add a flash, which can P-TTL, tilt and swiffel.

best regards KPM2