I have an affliction. I'm always flirting with Pentax. The only reason I haven't jumped to Pentax yet, or maybe never will, is because of the support. I don't need a vast array of lenses. They have the lenses I would want. I don't care about not having full frame (yet), as I would use APS-C anyways because my flirtation with Pentax is mostly for my wildlife and adventuring where I really have been wanting to get a more water resistant setup.
Why Pentax? Because a K5 IIs with a DA 300 F4 would only be $1500 and be as water resistant as any Canon 1D series and top shelf L from Canon. That field of view (480mm full frame equiv on 35mm format) would be enough for me when boating in the water which is why I'm always wanting this kind of setup. F4 is pleasantly fast.
I have a 1D2, but for me to have a fully resistant setup, my lens would have to be too, and right now, they're not. Not all L's are resistant to water, which is annoying. I like my 1D2 and 200 F2.8L, but that L lens is not water resistant. Only a few of the teleprimes that are L's are water resistant and cost quite a bit more (the typical 400 F5.6L prime is not water resistant). I think the only affordable 300mm and 400mm are the DO's and F2.8's. The F4's don't seem to be water resistant. So it's rather unaffordable for me to bother with these lenses since the whole allure is to have something that can take a splash. And that's what leads me to flirting with Pentax for cost. If I stayed with Canon for this particular setup, I'd go to a 1D3 or 1D4 for sure and get a 400 F4 DO II probably as it's water resistant, light and fast for what it is. Again, I do this from boats, like kayaks and skiffs out on the Gulf. But now we're talking about an easy $6k setup. Not worth it for me as a hobbyist. The lenses that I could get into would be like the Canon 300 F4L or Canon 400 F5.6L, but neither are sealed. Nor is the 400mm zoom. They cost the same too, so they would be affordable for me, but no seal makes it pointless for what I'm doing. Third party stuff, like Tamron & Sigma lack this too, so there's just no setup that is affordable with a fast teleprime other than Pentax it seems with top notch weather sealing.
So I go back to Pentax flirting, where I can get a water resistant APS-C with a decent resolution, decent ISO (I don't need more than 1600 for Florida sunny days), and a fast prime that has some reach (300 F4 is enough for my purposes on water on APS-C). I am used to 600mm on APS-C and APS-H right now, but I get a lot closer in my kayak and boats, so I find I often am coming back from 600mm to 300/400mm, so I know I could get away with that, and afford faster sharper primes at F4, and get more isolation too.
And even alternatively, there's the inexpensive 300mm all weather zooms from Pentax that are only a few hundred bucks. I keep flirting with this too.
I'm not thinking of totally swapping to Pentax. I'm just thinking of adding Pentax to my existing Canon setup, specifically for my water wildlife and potential weather photography, as I'd love to be able to set up in a storm and not worry so much about moisture, with a water sealed Pentax & all weather DA/Star/AW/WR lens that is way less costly than a Canon version and doesn't require a filter to complete the seal.
Suggestions? Is there a decent fast system that is water resistant that is affordable? I've yet to find something with the sealing without requiring third party enclosures, and none of those have the option for big telephoto lenses, beyond Pentax.
Is there a system that will compare in cost, weather sealing and overall speed/quality compared to a K5-IIs and DA 300 F4 at $1500?