[crackne]

Hi Folks,

I am hoping the Forum lens experts can help me out.

I am currently using a K10d with a Sigma 70-300 (non-APO version) mainly for capturing images of birds (both small- and large-bodied including Bald Eagles, hawks, etc.) and wildlife in general but mainly black bear, white-tailed deer, and anything else that happens to cross my path.

I am looking for a lens that will a) provide increased image quality (sharpness), b) additional "reach" in the 400-600 range (the bears are a little too close for comfort - I am still trying to figure out optimum camera-to-subject distances related to focal length), and c) be more suitable for capturing in-flight bird images.

Based on reviews found in this forum (and my budget), I have narrowed the field to three options and would like some advice/opinions (pros/cons) about these three choices. Any other suggestions would be greatly appreciated as well.

Options:

1. Sigma APO 100-300mm F4 EX DG + TC 1.4x/TC 2x

2. Sigma APO 50-500mm F4-6.3 EX DG HSM (AF Lens) + TC 1.4x/TC 2x

3. SMC Pentax-DA* 300mm F4 ED [IF] SDM + TC1.4x (I do not think the Pentax TC is currently available but I may be wrong)

I am leaning toward the Sigma 100-300 w/ teleconverters but I am open to suggestions.

Thanks in advance for any advice you might give me.
Cheers,
David