Last weekend I went out to photograph birds. It was a field trip organized through the class I'm taking. For the trip I rented myself a 300mm f4 and a 1.4 extender.
First the sites. We visited two spots: the Mountain View shoreline, and Moss Landing. We got to the Mountain View shoreline about 8am. I was there over two hours. The morning was very foggy, but windless. Not the worst conditions, but certainly not the best. I couldn't crank up the shutter speed without compromising on the ISO, and was shooting at f4 most of the time. There were an immense number of birds at this site. Really fantastic. Shorebirds, water fowl, sparrows... Even spotted a pheasant.
Moss Landing was a bit of a mess. It isn't the most pleasant site, and the person that had arranged the location wasn't able to make it there himself. There were lots of sea lions and a few otters. Lots of birds, slightly different from the ones at Mountain View. I was trying to photograph cormorants flying just above the water. These are hard birds to track! Though I think I got a few reasonable shots. Once again, light was a problem. Very foggy. But there was a little break on the horizon that let through a nice sunset.
I'm still working through the photos. I had several hundred by the end of the day. Working with a 300mm lens was immensely challenging. It's a wonderful piece of equipment. I'm leaning towards skipping the 70-200mm and moving straight up to the 300mm. If I need reach, I should get a lens with some real reach. At least that's my reasoning.
On the other hand, the 70-200mm will give me a good focal length for doing portraits. And is likely much more portable. The 300mm f4 is a heavy beast.
I don't think I'll be making a decision this year though. Budget constraints and all that.