I looked at and tried Canon 100-400 and compared shots taken with the Sigma 150-500. Currently using a Canon 40D body, I decided to get the Sigma 150-500 and very happy I did. Beautiful lens and not to heavy but I would recommend using a monopod to save your arms and wrists from the strain due to...

This Lens is just what I wanted. Great for wildlife photos.

Price a working Man can afford

at this time none

So far the lens works great. It is a little slow in lower light but not as bad as most people. The one negative thing is the cost of filters. If you want or think you need a filter spend the money and get a high quality one.

Sigma continues to innovate with their 150–500mm f/5–6.3 APO DG OS HSM ultra-telephoto lens. While designed for full-frame sensors, it's equally at home when used with smaller APS-C sensors. That's a lot of flexibility for one lens.

Wide focal length latitude; optical stabilization; reasonably priced

Not the best choice for consistent low-light work

For this price those lens fits the bill. I have not tried them out in multiple conditions yet, but for the price they cannot be beaten.

This is the third Sigma 500mm zoom that I've owned. The first was their non-OS 50-500mm, and then their 50-500mm OS and finally the 150-500mm OS. I use the 150-500mm on Nikons, including a D3, D700, D7100, D300 and D2X.

Reach; Silent motor; fast target acquisition speed; reasonable price; sturdy build; lightweight for its size

Some may find it "plasticy", but the use of plastic keeps it both lighter and less expensive; MF only with a TC

The Sigma 150-500mm f5-6.3 DG OS HSM superzoom has the most important aspect of any modern long-focus lens – an efficient AF drive system. This is very much the Sigma superzoom's forte.

Impressively quick and quiet automatic-focusing

Significant softness at wide aperture