Originally posted by mikesbike The lens I recommend, if you can, is the DA 18-135mm f/3.5-5.6 which has a very large, useful zoom range, but with exceptionally fine build quality and WR (Weather Resistant) construction. It also provides fast, quiet, accurate autofocus (AF).
+1. A great budget buy, and an ideal lens for a beginner, for the uses you describe, at around $250 used (e.g.
Used Pentax SMC DA 18-135mm F/3.5-5.6 ED AL (IF) DC WR Lens). You might find one bundled with a camera, for effectively even less. This thread might convince you about capability of the lens:
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/179869-da-...at-can-do.html
Use a lens like this for a while and you will see what your preferred focal length(s) are. If you stick with the DSLR thing, you can add other specialist lenses later - e.g. a wide angle lens, a high-quality portrait lens, a telephoto lens, a macro lens, etc. If not, you could sell it with minimal loss. Not that I would discourage you from getting a cheapish prime lens to complement the zoom - e.g. if you can find a budget macro lens or something suitable for astro.
As for the DSLR bodies in your list, any of them would be fine but personally I'd go for the K-S2. It's a lot of camera for the money, with all the features a beginner could want, without the bulk of the flagship models (K-5 series, K-3 series, etc). The flippy screen is really useful for macro and any other shots not taken at eye level.
Don't laugh, but if you get one in a colour that isn't black or silver, people will find it less intimidating. I got a white K-S2 just because it was cheap, but I've come to really like it.
One thing that hasn't been mentioned. Leave $80-100 in the budget for a flash (less for an all-manual one). The popup flash is OK for fill, but for portraits, macro and low-light you will soon want something more capable, especially with a slow-ish lens (ie maximum aperture isn't very wide) like the DA 18-135. Plenty of threads about which type of budget flash to get (e.g.
Help with first flash - PentaxForums.com). You can also get diffusers of various kinds very cheaply or make your own. Some camera bodies (e.g. K-3, K-5, K-30) can control a suitable off-camera flash wirelessly; the K-S2 can't, but there are cheap workarounds like using a cord or triggering an off-camera flash in slave mode with the pop-up flash, or you can add a radio trigger system.
Originally posted by Brooke Meyer Entry level cameras make it really hard to control your image or at least make the one you want by burying the essential controls. I spend a lot of time in my basic photography classes helping folks unearth the controls they need.
I'm sure you have more experience than I do with this Brooke, but surely one thing about Pentax is that even the entry-level cameras like the K-S2 allow a great degree of control right away. For example TAv mode with a narrow ISO band, or fully manual mode, can be set very quickly. Separate wheels for aperture and shutter speed. If you set up the camera through the menus you can have back-button AF (admittedly that's a little buried), DNG, suitable tracking, etc, before you start. And you can set a couple of user modes (e.g. one for birds in flight). I didn't really find it harder to set up the K-S2 for the controls I wanted than I did the K-3; if anything it was simpler because there were fewer options. Of course I like having a top screen on the K-3 and things like a dedicated ISO button but the major controls really aren't that different are they? The K-S2 (like other entry models) has Scene modes that the flagship models don't, which may be useful for those who don't attend classes like yours, and are handy when you give the camera to someone else, but there is no need to be seduced by them. ;-)