Originally posted by Joshua A Well, I would agree with the 50-135 being a great choice for portraiture, but unfortunately I also enjoy taking landscape photos, something that is better suited to a wide-angle lens than a short telephoto, as personally I find using a telephoto for landscaping takes both more discipline and planning. On the otherhand, I do currently find myself using the long end of my 35-70 quite a lot for taking natural portraits of people, especially seeing that the f3.5 aperture allows for both a shallow depth of field, and a slightly less sharp image.
When it comes to lighting, I only currently have a homemade light box made of a polystyrene box, and my on board flash, so using available light is quite important to me currently. Also, I and now using both Adobe Lightroom 4 and Nik Efex for my PP, so hopefully this combination will last me quite awhile.
Personally, picking up some autofocus primes is a little out of reach, due to the relatively steep pricing of the DA* lens, so maybe in a few months I will consider picking up a Limited or Sigma Art lens. So, thanks for all the help, and I would really value some more opinions on the matter!
A used Tamron 28-75 is about $325 USD. Has a minimum focus of 12", very versatile for landscape and portrait. I've made and sold both with that lens. If I could only have one lens, that would be it. Pentax 50-135's have been going for about $750 USD at KEH.
You don't need a ton of lighting gear. A window with a sheer curtain (aka softbox) will do wonders. No curtain? That why I have a shower curtain liner and a few suction cups in my lighting bag. Add a homemade reflector ( sheet of 20x30 white foamboard) and you're in business. I have a couple of collapsible 4'x6" reflectors I got on sale for about $60 a piece including stands & case. I make my own head shot backgrounds (okay my wife sews the seams) from fleece fabric, about $18 for 5"x9". Cut a 2"x2" to 5 ft., drill a whole in the middle for the spigot on a light stand, drape the cloth over and you're in business.
You can do a lot with a manual flash ( Yongnou 560 for about $60) on camera and flagged with $1 piece of black foam (aka the "
black foamy thing"). Neil's site has what you need to learn. You can go off camera with a $20 to $30 wireless trigger set like a PT04. Shoot through umbrellas and a bracket don't cost much.
Another poster made a great suggestion. Sell the stuff you really don't need but may seem comforting because you have a lot of stuff and get 1 good one.
Landscapes, get a good used tripod and a wired remote release, get used to 2 sec MLU which turns off SR on your K-5.
Invest you're time in learning, there's a lot of free info out there. It'll pay back more than any equipment you can buy.