Originally posted by Rondec Choosing a new lens (or used lens for that matter) seems to be one of the most difficult things for people on the forum. I guess I thought that I would share my mind set with regard to choosing what lens to purchase and hopefully others can give input too.
First of all, I think the most important feature of a lens is focal length. There is no turning a 200 mm lens into a 8-16mm zoom. Deciding on what focal length I need/want really narrows down the decision process. I don't think I can emphasize enough that the focal length is the crucial feature of a lens and figuring out what you want/need in this respect is the biggest factor in my decision.
Second, I think comes budget. This really comes near the top for me. Even if there are great lenses out there for 2000 dollars, they aren't going to be for me. At the same time, it is important to pay for quality. It is better to save for a lens that I will really use and enjoy than to buy a cheaper option now, that I will want to sell in six months because its lack of quality frustrates me.
Third comes everything else. By now, I have usually narrowed my search down to two or three lenses and I can focus on individual features. Wider aperture, size, build, and bokeh are all important features that can push me one way or another.
Finally, I think it is important not to buy lenses based on the lens club photos. Just because someone else can get the DA 15mm to work well for them, doesn't mean that I will be able to do the same and in fact, I don't really like to shoot that wide. There is always a "hot" lens that everyone else is making awesome photos with, but that lens often isn't what I want or need.
By following this decision making process, I have been able to avoid LBA and actually collect a set of lenses that I both use and enjoy.
Much of what you say is true, especially about the point that just because someone else has taken great shots with a lens, does not mean you will,
BUT what it does mean is if you know how to use it,
YOU CAN.
there is a big distinction in this point that many people miss, it is the photographer, not the equipment that takes a great photo.
However, on the point of choosing a lens, and I can't stress this enough, you need to think about where the lens fits in the general scheme of things.
My own opinion, and this has been criticized in the past, is that if you want to enjoy a large range of photographic interests, you need a basic kit with a range of 10-12mm at the wide end, to 200 mm at the long end, and if you are interested as well in nature, this should have a means of getting out to 400mm.
I used to think that F2.8 over much of this range was important, but it may be that F4 is OK, given the performance of later bodies like the K-r and K5 especially.
I usually recommend this to be in 3-4 zooms, as you like
My own kit covering this range is :
sigma APO 10-20mmF4-5.6 EX DC
Pentax FA-J 18-35 F4-5.6
Tamron XR di 28-75 F2.8
Sigma APO 70-200F2.8 EX (first version non DG non macro)
Add in a sigma TC or 2 and I get to 400mm with 4 lenses and from 28-200mm at F2.8
With this you can do a ton of shooting and never need anything else unless you adapt a liking for fast primes.
you can save weight and cost by going slower, and or shorter, especially if you don't see nature shots as a main interest, for example you could get an ultra wide zoom (sigma 8-16 or 10-20 or Pentax 12-24) something in the 16-18-50mm range even a kit lens, and then perhaps the pentax 50-135 F2.8 for the tele, still a very good setup, and down to 3 lenses, and reduced weight over my kit.
The point is, you simply need to think about your purchases carefully, and purchase quaility lenses (not always overly expensive) to get the performance you need.
Read the reviews, especially those that talk about difficulties with a lens, they may be more useful than one that just raves about the great shots, without saying it is tricky to use, etc.....