Originally posted by grispie From there on you will understand what you need.
To be honest, the DA 20-40 that Ron suggest. I agree with him, but not right now. Same for all stellar quality lenses with high prices.
At this moment you shouldn't/can't decide on those. Too much to learn.
My strategy was different. I owned some lenses to find out what suits me and my style off photography. So the answers to that are for everyone very different. They even are for me now compared to 2008. It evolves with the learningcurve in photography over the years.
So what didn't I do:
I see it to some people. They start with the doublekit K-30 (was before K-x or K-r) and then they think, o I can use something better. They find the DA 16-45 and put the 18-55 kit somewhere (it was only 50 bucks). They learn and by the 17-70 wich is beautifull and only lose 50 bucks on the 16-45. Fun for some time, but the 16-50 is better and again they loose 80 bucks. The K-30 becomes a K-5 (second hand) and that makes up for a K-5 IIs (second hand) but they want the K-3. The 50-200mm becomes a sigma 70-200, not the current version, but the HSM II version, wich is fine and they only loose 50 bucks on the zoom. But then they know that the new Sigma is better or even the Tamron and again they upgrade. This is the best way to spill money.
So I started with K20D with DA*16-50 and DA*50-135mm in januari 2009, after a bridgecamera in 2008. That was a nice learningstage, since all items in my camerabag where firstgrade! I only neede to learn to be as good as my equipement.
The camerastory:
I kept the K20D till the K-7 was announced and alomost in shops. I descided that body-upgrade was something just to do. The K-7 was nice and had a limited moviefunction. So I made a plan on how to handle the camerabody's. I descided to upgrade when a new one arrivés and with the K-5 coming I knew I neede two body's, so sold the K-7 and bought two K-5's (one Silver). Keep the Silver and refresh the black K-5 (had 4 off those and then one K-5 II) since I make a lot off images with sports. Took a yellow K-01 (also a keeper) and now a Silver K-3 (also a keeper). So on this strategy I know have 3 body's, but with K20D/K-7/K-5/K-01/K-5II/K-3 I had 11 camerabody's wich didn't cost to much, since I sell good and bought almost all off them with refund-actions from Pentax. But I made a budget for them and the rest.
The lensstory:
My first mistake was go to a store and try the 40mm Ltd. It was very cheap at that time (remember Pentax was a money losing firm in that year). So that lens was better then my 16-50mm and smaller and lightweight. That was the first stage off fasing out the 16-50mm lens and wenn the DA*55mm (portraitlens) came it had to go. I tradet the 16-50mm for the DA14mm and some money, put in some extra money and bought the DA21mm Ltd. I bought a Sigma 170-500mm (old stock new) and sold it without loss to get the FA*85mm (also portrait and sports). I neede a longer lens for an event and bought the DA*60-250mm lens second hand, it was a rush thing, great lens but wanted for indoor sports a faster lens with f2.8 so I sold that lens without any loss after a few months. Then I bought the Pentax DA*200mm, but had a bad luck with that lens, could return it to the shop and instead I took the Sigma 70-200mm, wich made the DA*50-135mm obsolete (to slow in focussing for sports). Then the DA*300mm came. Not complete happy with everything, since the DA14mm was great, but not my lens, so I sold the 14mm and 21mm to fund the FA31mm, wich was a great choice. Toyed around a little and had a DA15mm, DA10-17mm fishey and DA12-24mm, but lost no money on the sales off those secondhand lenses. So that leaves me today with the six lenses 31mm, 40mm, 55mm, 85mm, 70-200mm and 300mm. I'm planning on replacing the 40mm with the 20-40mm. I didn't lose much money on all these lenses and when I use them for another few years, who's complaining.
Make a budget:
I made a budget at some point to keep controll on things. Initial costs are always high, since you have nothing to start on. I made a calculation and budgetted 200 euro a month to cover the expenses. That seems a lot, but in reality it is just enough when you want to have a good set off lenses and camera's (more body's cost more money). In this budget I also cover memorycards (they where expensive a few years ago), software like LightRoom and Elements, a 27 inch monitor with high resolution (2560x1440 pixels) and the needed upgrade for my computer, camerasupport like monopod and tripod, camera mic for video and video ledlight, camerabags and so on and so on.
It just never ends, unless you are smarter then me....