I am looking for a backup or to use as a second camera at weddings. Olympus ( Model and zoom lens), Pentax DSLR ( Lens ?), I am not sure about Sony. I am not concerned about the weight of the camera just IQ and ISO Max 2500. I Shoot flash on a bracket and OCF as well. Any suggestions. Thanks
I assume you ask the question because you can't or won't buy a second copy of your main camera (which would be preferable). With m4/3, and if you can live with f/4, the E-M1 II and Zuiko 12-100mm f/4 would be hard to beat plus a fast prime for ambient light, like the Zuiko 25mm f/1.2 or PL 42.5mm f/1.2. If you can't live with f/4, the Zuiko 12-40mm f/2.8 is nice, and the Zuiko 14-35mm f/2.0 in 4/3 mount with adapter (full functionality on the E-M1) even nicer.
I'm not a Pentax user, but I assume that the K-1 would be the best Pentax for weddings. I would even go as far as saying that for this particular use, I would prefer it over any m4/3 camera unless weight is an issue. I don't have a clue about Pentax lenses though, except the fabulous 77mm f/1.8