Originally posted by jeffryscott Pentax, admittedly, is a niche player. As is, well, anybody else but Nikon and Canon. But Pentax seems a little more niche than the others. For converts from other systems, what has brought you here?
As for me, I spent 25 years in newspapers using primarily Nikon and Canon. Went small and light with m43 and wanted more, so went with a Pentax K5II in 2013 for a summer. Loved the IQ, the ergonomics, the 16-50 and 50-135, but the C-AF was lacking. The reach with the 50-135 was a bit short as well. I spent a lot of time at the pool as both my daughters were in swim team and the AF was OK, but not great, so ended up in the Nikon camp. The AF was fast, but the D7000 wasn't nearly as nice to use as the K5II. It was also so big (the whole kit) and I wouldn't take it with me. Shooting was a chore.
A pro friend bought into Sony and the A6000, and claimed it the greatest camera since who knows when. I jumped. AF was great, but the camera had no soul - and a horrible lens selection. Fuji called. I'd always wanted an X-Pro 1 since its introduction. Loved it, it slowed me down, IQ was brilliant and the Fuji 23 and X-Pro 1 blew the A6000 and Zeiss 24 away as far as IQ. But the photojournalist in me wanted a more versatile kit (even if I didn't really need it). The X-T1 called as I wanted some extra reach with the 55-200. Again, loved the IQ but the camera was slow and funky ... Olympus E-M1 time. If I was still a news photographer, the Oly kit would be my current choice. Small, light, great reach and more than adequate IQ. A kit like that would have saved my back from years of carrying a fully-loaded Domke bag. While, if I was honest with myself, the IQ is more than good enough for my needs, I kept getting drawn back to the Fuji files. For me, the Xtrans sensor is sublime. I gave the X-T1 another try. A few firmware upgrades and the camera had transformed into a much better machine. I added the 18, 35 and 55-200. Nice little kit, but while the camera was weather resistant, none of the lenses were. To upgrade I would need the 16-55 and 50-140. I never bought those, they are expensive and huge and I kept thinking of my old Pentax 50-135. Much smaller, half the price and optically close to the Fuji. Whatever weight the Fuji body saves, those lenses negate the size and weight savings. I didn't make any changes with the Fuji gear but was thinking of where to go ...
Then my daughter needed a new camera for her eighth-grade photography class. Pentax was my first thought - a used K20D and 18-55 for $150 beats anything Canikon could offer. And then I realized Pentax was an option for me, but this time with the 60-250 for the extra range I missed with my original 50-135. Fuji went for sale and my return to Pentax was complete with a K5II, 16-50 and 60-250. I can fit the Pentax kit in the same bag as my Fuji kit, and although it weighs a bit more, it isn't that much bigger and I an still carry it with me everywhere. I do want to add a K3II (the money wasn't there this time around) and Limiteds, but that is down the road ....
Pentax, in my mind, is the best bang for the buck for build quality, IQ and optical quality.
Started with Pentax MX back in the days. After my beloved MX was stolen, based on a pro friend's recommendation, I went to Nikon (FM2, FE2, F3). When digital came out, I went to Fuji S1 then Canons for the rest of my ride until I bought a K5IIs package with the Three Amigos which overlapped with my Canon 6D. I sold the Canon gear and stayed with Pentax. Later upgraded to K3. Like you, I am not thrilled with the Pentax autofocus system. As I mentioned, I have the Three Amigos, the 16-45, Sigma 10-20, F50 2.8 macro and a bunch of M42 and a few Pentax 645 lenses. Overall, I am more than happy with the quality of the Pentax system images. The three Amigos are unmatched by Canon or Nikon. The SR is a major advantage, Pentax small primes are second to non in quality and workmanship. The only thing I am missing is a longer zoom and mid-range zoom. I am looking at the Tamron 70-200 as I can not justify Pentax 70-200 price.
Now that I shoot more nature and landscapes, I have become interested in the Sony FF offerings. I am waiting to see what Pentax has to offer in the FF arena before my final decision on the future of my FF system. After the switch to Pentax, I have invested in FA lenses in anticipation of a Pentax FF. If my work involved video, I would have ordered the Sony A7RII already as I know Pentax will most likely come up short in the video department of whatever the FF camera we see. Not being a video guy and wanting a lower price which I fully anticipate from an FF Pentax, I am going to wait a little longer before a final decision. One of the greatest advantages of the Sony FF mirrorless is the fact that it would allow me to use every single lens I already own Pentax or otherwise.
With a Pentax camera around my neck, I am the odd man out in my pro photographer friend gatherings. They are all curious as to why I switched from Canon until they see the images that come out of my K3 and the FA limited lenses. Then they all start marveling at the quality and compactness of the K3 and "Leica like" quality of the lenses at Pentax prices. Now, if that is not a winning combo, then I don't know what is!