I have never been terribly interested in wildlife photography, quite frankly the price of the lenses required are out of this world, $10-13k for a lens? No thank you! When Tamron introduced a 150-600mm lens for just a hair over $1000 I knew I had to get my hands on it.
The build quality of this lens is fantastic, it is solidly built and comfortable to use. It is also surprisingly light, I could actually hand hold this lens for a long time! I know this will not be the case for most people, but I found it quite easy. The lens weighs in at 4.3 lbs, compare this to Nikon's 70-200 f/2.8 which weighs 3.39 lbs, 1 lb more for an extra 400mm!
Let's be real though, it is a slow lens with a maximum aperture of f/6.3 on the long end. To compensate for this Tamron uses a very effective Vibration Control, I had no problem hand holding this lens with less then preferred shutter speeds.
I found the lens to be extremely sharp even when shooting at 600mm when shooting a subject that was relatively close to the lens, meaning less than infinity for the lens. Below is an image taken at 600mm, along with a crop of the same image.
Of course one problem with a slower lens is achieving a fast enough shutter speed for moving subjects. I came across this bald eagle in the Wind River Range, the shots with the bird not moving were sharp, but in movement it was blurred, BUT this was my mistake. I was in shutter priority with only 1/1000 selected, my ISO was only 640 so I could have easily increased the shutter speed to 1/4000 to keep the bird sharp in movement. I only bring this up because it can easily become a problem in low light.
Below is a comparison of size to the Canon 70-300. It is a big lens but would fit in most backpacks. For 600mm I would consider it quite compact!
There was a bit of softness at 600mm when the subject was at infinity, I personally found it to be acceptable for my needs.
Overall this lens is an incredible value and I had a blast using it. Sharp at 600mm for 1/10th of the price, who can argue that? It's no f/4 lens, but you won't have to take out a 2nd mortgage to buy this. Keep in mind that I was using this with a Canon 6D which is a full frame camera with mediocre AF. If I were really interested in getting into wildlife photography for very cheap I would get a Nikon D7100 which has 51 AF points and 6 fps, with the cropped sensor you have a 225-900mm! Or the Canon 7D which has 19 focus points and 8fps. For just over $2000 for either system, that's game changing.
Note: B&H sent me this lens to review and the links in the article are affiliate links, these cost you nothing extra and help to support me to keep doing these reviews!