Lens sharpness
I find this to be the most difficult choice I have been faced with regarding camera/lense gear. I have a 40 D along with a fair variety of lenses. The long focal length has become more important to me in the past year as I have had many opportunities to shoot wildlife and birds. My primary reason for purchasing the 50-500 (Bigma) was for wildlife in Yellowstone Park. It has served me well in some respects. The detail or sharpness has proved to be less than satisfactory unless I have a real bright day. That is not the worst of it though. The weight is not a problem at all. The tripod mount serves as a great handle that works very effectively. The lens build is excellent. The lack of IS is somewhat of an issue. I mean it would be a nice addition I would use no doubt. OK, the big problem is trying to use it to track BIF (birds in flight). I want and need to be able to set my camera to AI Servo , multi burst and set my focus points. Then I want to shoot birds such as ducks, geese, eagles, osprey etc. In this area I cus the Bigma often. I know, this is not a fault of the Bigma. It does what it was designed to do very well at a much more affordable price than other 500mm lenses. It does get you close to your subject.
I used to have a Canon 100-400 IS. I sold it to get enough cash to buy a Canon 70-200 f2.8 IS lens. At the time I needed the 70-200 2.8 to shoot sports at night. I am very happy with that lens yet but it is not a birding lens for most instances. I recall my 100-400 IS as producing some nice sharp images along with good to excellent color contrast and some fabulous bokeh. How did I ever sell that lens? Well, at the time I was not into birding or wildlife. I do not remember if the 100-400 I S was a fast focusing lens, I mean fast enough for locking focus and tracking the above mentioned birds. The weight was never a problem . I was not that fond of the push pull zoom because I feared it would make the lens prone to dust.
I have read hundreds of reviews on lenses like the Canon 300 f4 IS , the Canon 400 5.6 L and other great lenses. NOTE: I can not seriously consider a Canon 500, 600 or 800 because they are out of my league. It would seem that most people who have used the Canon 400mm 5.6 L agree that it is undoubtably the sharpest of the lot, although it like the 300 f4 are not zooms. I would love to have the sharpness of the 400mm 5.6 L and the versatility of the 100-400 5.6 IS zoom all in one. That however looks to be impossible unless a person could somehow land the absolute sharpest of 100-400's.
I have been marketing many of the pictures I have taken in the park on the internet. My success has been limited by the quality of images I can offer. Some photo buyers want a very high level of quality. I will need to upgrade the glass I use if I am going to succeed at selling these pictures.
I am satisfied with the 40 D as I have become more than efficient with the cameras controls. It is capable of performing real well. But in the world of photography I find that the glass has the ability to hinder the camera from doing what it can do.
Based on what I have read here in this thread and the internet overall, I think for me it comes down to two choices. I can either get the best of the lot in sharpness in the 400 5.6 or I can settle for a tad less in the sharpness department and gain versatility due to focal length as well as IS and get the 100-400 5.6 IS.
I therefore will be selling the Bigma to raise some of the cash to do that. As I see it, I will lose the extra 100mm but I will be improving in all other departments. Thanks for all of your input on this choice and hopefully someone else might get a bit of insight from my observations.
