I am new to bird photography and to the forum. I am writing from very snowy Philadelphia. I am asking for advice about which camera system to invest in for the long term for bird and general photography. I have a used Pentax K10D which I bought about a year ago to get back into photography after a long hiatus. I have no complaints about it as I learn. I am in my sixties, and over the last 15 years I have become a birder, by no mean expert but competent, and I enjoy it when I can get out.
My new and disturbing desire is to take photographs of birds, in their natural habitat at rest and in flight. As I read about bird photography I am discovering how hard and expensive a business it can be. Some advise finding an easier way to enjoy oneself! I have given myself limits as I set out on this quest: First, I want to do my best with cameras and lenses that are good enough for the job, not frustrating and inadequate but also not the very best for the job. I can neither carry for long periods nor afford the best, heaviest FF camera plus the longest, fastest lenses, etc, and I can make my peace with that. Secondly I see myself doing lots of round and about photography, people on my street, places in my town, etc, as well so my camera/lens system must fit in with that too.
As I read through many bird photography sites I am aware that most bird photographers use Canon or Nikon equipment. On the other hand there are photographers, in smaller numbers, who pop up with beautiful images from their Pentax (often with ancient, hard to find, but great lenses), or Oly or Sony or whatever equipment. The work is often presented with passion and conviction that their's is the only way! I don't mind the enthusiasm as long as I can find some useful information between the noise. So far at least I am not committed to any brand. My investment in Pentax is small enough that I can sell a few lenses and that's ok. This leads me to think of (at least) four choices, and I'd appreciate the thoughts of those who have tread this path before:
1. Upgrade to a Pentax K-7, and get a new DA*300/4 or other used 300mm lens (it is hard to find longer Pentax lenses I am discovering), together with at least a Pentax 1.7x AFA TC. This should give a reach of 510 mm, 765 mm 35mm equivalent. Is sticking with Pentax a good idea or a path to frustration? For example, I know some commenters on the net have concerns about too slow AF with Pentax.
2 a and b. The Nikon D300 or Canon 40D are no longer "this year's model" and are available reasonably priced used, or I am able to splurge for Canon 7D if it is seen as a great and long-term investment. I assume its high megapixel sensor allows for images to withstand more cropping and hence a little less lens reach will be ok (is this correct reasoning?) These three are all somewhat bigger and heavier than the K-7 but obviously are excellent cameras (esp. D300 and 7D). One factor here that may be important is that if I buy a modest lens (as long lenses go!) to begin with, Nikon and Canon pro lenses can be rented locally (and I assume globally) for a special shoot. If this general idea is good, how to make the choice between Canon and Nikon? Which option fits in best when combined with a reasonable walk-around general use camera? What lens or lenses to start with for bird photography work?
3. My crazy but fun idea is to get a micro 4/3 Panasonic GF1 or Oly EP-2 which would be great for walk-about photography. For birding there are several 4/3 telephoto lenses in the 300 - 500mm range which can be used with an adapter on micro 4/3, and the 35mm equivalent FL is doubled by the 2x crop factor; they have a 1.4x TC as well. Questions here I think are whether the viewfinder options and AF are "good enough" so that bird photography doesn't become frustrating. Or is this use asking too much of micro 4/3?
In that vein, is it asking too much for a good enough bird photography camera also to be a good camera to take about all day for general use?
So many questions! What am I missing and can you give me some perspective to help me sort it out? Thanks.