Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: The choices of compatibility does not mention 40D.  Is it compatible?
Document: Buy this lens!!! !Also ready to go to FF from 40D to 5D soon.
For sharpness, I couldn't ask for a better performance.As for distortion, the Tamron has some minor barrel distortion at 28mm. It's not bad, and easily correctable with my camera's software. Pincushion distortion at the telephoto end is well controlled and not noticeable in most cases. Again, where it can be noticed, it is easily fixed. If you use a crop-frame camera, such as the 40D, 50d, 7D or any Rebel, distortion won't be an issue.
My copy delivers biting sharpness and snappy contrast over the whole focal length range and focal distance at F/4 or above. As expected, F/2.8 shows a little softness plus the propensity for misfocus on my 40D. The macro feature is tremendously handy. So is its downsized construction. It is my perfect lens for studio portraiture or street candid shots.
There are "crop specific" (DX or EF-S) lens which offer greater zoom ranges than this lens, but at the cost of aperture and full frame compatibility. In that regard, this is a unique, affordable lens still worthy of consideration.
I monkeyed with the Nikon grip buttons and everything came back. I am blaming the grip (official Nikon) and not the lens necessarily, but it was weird and hasn't happened again yet. Just thought I would mention it in case anyone else experienced this.The day after I purchased the lens it seems the zoom lock slider button is broken.
I purchased this lens for use with my Canon 40D with the intention of it being my carry around everyday lens. I had a Tamron 18-50 in the past that was a terrific lens. Unfortunately, this lens does not live up to the past Tamron lens. Picture quality is a bit on the soft side, and the focus is a bit slower and mis-focuses more than I'd like.Overall - I feed the build quality is very good.
I purchased a used 40D a few years ago. As I quickly learned about the camera, I just as quickly learned about how much money I "could" (but won't) spend on glass. My wife made it clear that she wanted something that wasn't heavy. That was understandable, the kids move fast so she has to keep up. So when you add up the requirements (f/2.8, less weight, low cost), you arrive at the 28-75.
A friend of mine recently purchased a 5D after switching over from another brand. He rented the 24-70 for a shoot since he didn't have any canon compatible lenses yet and was very happy with it. He wanted to buy one for himself but I convinced him to check out my Tamron before he made his decision.We set up his 5D on a tripod and took shots of the same subject from 28, 50, and 70mm from both the canon and tamron lenses.
You may have noticed I didn't even mention using this lens at 2.8 but if you don't need the corners or perhaps want a slightly softer portrait, sure.Build quality seems fine to me and keeps weight and cost down. Honestly, if you are tough enough on your lens for this to be a concern, just get the Nikon 24-70/2.8. Then again, you could buy almost 4 Tamrons for the same price.
That will give you a range of 10-75mm, or when converted to 35mm equivalent, a range of 16mm to 120mm. Which is a damn fine focal range for travel, and relatively lightweight at that (not to mention very sharp throughout). If you need to add a third lens, the natural choice would be to get theCanon EF 70-200mm f/4L USM Telephoto Zoom Lens for Canon SLR Cameras.
Answer: Yes. I used it on mine and was very impressed. Especially with flash work, it's very sharp.