Since I have two systems, I think I can go with two favorite lenses. They are at opposite ends of the extreme though...but then I am funny like that.
1. For the Canon (just don't throw rotten food at me please j/k) it would have to be the Sigma 50-500mm f/4-6.3 EX DG/HSM, otherwise known affectionately as the Bigma. During the warm weather, it is always on my Canon 20D.
Here is a photo of my wildlife set up. Bigma, 20D, and Bushawk shoulder support.
And an example. This was taken at 500mm, f/6.3, 1/1250s, at ISO 400.
They do make this lens in a Pentax mount, but it does not have the HSM capabilities. With the Canon system, I do enjoy the faster focusing that this lens has to offer, especially for BIFs (Bird In Flight).
I find its weight reassuring. It is heavy enough that you can hand hold this lens easily enough. The tripod mount has finger holds that fit my large hands nicely when I rotate it 90 degrees on the lens. This allows me to slip my hand between the tripod mount and the lens for a comfortable hand holding experience. Likewise, the wide range is very useful. It gives you a very slow 50mm lens, but I have found it good for taking images of animals that appear closer to you (with nature, you just never know what you will encounter, and where). It is the perfect nature walkabout lens in my humble opinion.
I am looking for something different for my Pentax system. Possibly a fast 300mm coupled with a teleconverter or two. Maybe towards the end of this new year will I have something, but with the Bigma, there is no hurry.
2. My second favorite lens, this time on the Pentax system, is the Pentax 10-17 f/3.5-4.5 ED Fisheye. I just recently bought this lens and only had a few chances to take it out, but wow! It was always a dream to have a fisheye, even back in the days when I was learning how to take photos. These types of lenses were super expensive glass at one time, well outside the reach of many people. Today, we are absolutely spoiled. I only paid 499 Canadian for this gem, and what a gem it is!
At 10mm, it gives you a rectilinear 180 degrees field of view. This is massive and about as extreme as you can get short of a 360 degree circular fisheye on a full frame camera. Combine this with a close focus range of a mere few inches, and you have something that can do things that very few lenses can.
I have found that you can control the amount of distortion with careful composition. Horizon lines that run dead center are nice and straight. Move that horizon line up or down and you get increasing amounts of barrel distortion. It is quite a nice effect. Now the lens is a zoom. At 17mm, the fisheye effect is minimized. It is still there, but you do have to look harder to see it. This makes the lens a true versatile performer.
Here are a few examples of the few times I took it out for a spin.
My K10D was only a few inches away from that wooden bowl of fruit.
An example of fisheye distortion. Note how much that horizon line is curved, but then, it is well above the central plane.
Here are two examples. The first showing the lens at 10mm, the subject is my workplace. The second shows the same scene but defished using Corel Paint Shop Pro X2. I was curious to see what sort of effect I would get. These are rough examples with little PP added to them. Note the slight purple fringe in the lighting. This is about the only bad thing I can say, and even at that, it is fairly well controlled.
Last edited by Chako; 01-01-2008 at 09:39 AM.