As I wrote the other day, the Bald Eagle nest at Peebles Island State Park motivated me to work on improving my options for long range wildlife shooting. I decided to go for longer focal length rather than improved image quality. I mentioned that doing both wasn't financially feasible.
There's an actual camera store about a forty-five minute drive up the Northway from me and they had a used Sigma 150-500mm lens for sale which I managed to obtain by trading in several of my lenses, including the Canon EF 70-300mm lens I was trying to improve upon. While the image quality is not an improvement over the Canon, the range certainly is.
Here is a shot from this morning, cropped to the same size as my photos from the other day. You can see the increase in focal length. It was overcast as I was testing the lens which is a cause for less contrast than the photos from the other day. Quality should be similar in similar conditions.
One difference is this lens is big and heavy. Almost four pounds without the camera body. Here it is extended to 500mm attached to my 7D with grip.
While I shot with it hand held this morning, there is a broken off sapling trunk at just the right height to rest it on at just the right location. In the future I'll make sure to use my monopod.
I reprocessed the RAW file with DxO Optics Pro 8, which was free once later versions were released. This software downloads definitions for camera/lens combinations and corrects lens aberrations, much like Canon's DPP software will do with Canon lenses. Here is the same image above, corrected in DxO Optics and then slight contrast and sharpness added in DPP.