The reality was I also needed to learn the skills of chasing birds in flight, something very difficult to do with a 600mm lens, so why not start with a maximum reach of 200mm right?
I started with birds on the ground, waiting for them to take flight and let the camera shoot at 10FPS, which is how I captured the first bird in the gallery below. I tried to stay around 1/1000s shutter speed but on many images I was getting motion blur to varying degrees. But still, I was pretty happy with the overall result, for a first time out.
I continued this tactic for a while and managed to get some decent results, such as the seagull (second image in gallery below) about to land in the rocks on the shoreline. I quite like the shot but it does highlight one of the weaknesses of the Tamron 8-200mm lens, the bokeh. The bokeh is fairly circular, but it is somewhat ugly, although to be fair I have had better results at different focal lengths from the lens.
Having had some success with the birds on or near the rocky shoreline, I moved on to trying to chase the birds midflight which proved to be very difficult. It occurred to me that if it is this difficult with 200mm, what will it be like at 600mm? Anyway, I realised I needed to use a faster shutter speed, and tried to keep it around the 1/2000s – 1/2500s shutter speeds. The third image was a pretty impressive result, particularly for a 200mm lens.
I kept at it for another hour until I managed to get the fourth image below. I was very happy with this result, and particularly considering the lens that captured it is a 28-200mm travel lens! For the money the Tamron costs, it is a truly excellent value, offering very sharp results across the focal range, and is compact and yet bright at f2.8-f5.6. I certainly asked more of the lens than it was designed to deliver, but I am very impressed with the results. Now all I need is to start using the Sony 200-600mm, and that I know will be more of a challenge.