Bests & Worsts Reviews from Amazon

Lots of things to like and a couple annoying things to think about.... I am an amateur photog of 30 years. Always a Canon person, shooting a 7D and 7D Mark ii now. When on vacation I like to bring a Tokina 10-16mm 2.8, Canon 50mm 1.8, Tamron 24-70 2.8 VC, and Canon L 70-200mm F4 w/1.4 adapter. For an upcoming trip I wanted one lens for my new 7D Mark ii. I looked around and the lens with the best zoom range you can get is the 18-400mm Tamron. I bit, purchased on Amazon and took it to Galveston to take some shots. First thoughts: It's a well built, solid lens but a tad lighter and less sturdy than my Tamron 24-70 F2.8. Good overall build quality. The lens is a little slow to extend starting about 1/2 way down the barrel. Going from 18 to 400mm ain't easy so this is not an issue really. First few shots I found the camera to be accurate and well suited for candid shots of people, some birds and the architecture on the pier. The color rendition is nice and bokeh is good. I will say my 70-200 F4 L is much better, but that IS expected. The Tamron is MUCH better than many standard Canon lenses and it has fielded some great shots. Here is where the problems are: 1. When out past 300mm, you will find that you have chromatic aberration (odd color along contrasting edges - See pics I included.) How is this a problem? If you need to crop down you may begin to notice these. When pixel-peeping in Photoshop its quite noticeable. If you're using filters to enhance contrast or colors, these aberrations may be come enhanced and more visible. 2. When you have your camera to your face to view your subject in the view finder and if you are retracing or extending the lens you will feel air being pushed from the lens to your face exposed under the back of the camera. How is this an issue? What most people don't realize is, when y you are using a zoom and you extend or retract it, if it's not totally sealed, air will be pushed out (retracting) but ALSO pulled in (Extending) this is a big problem over time as dust will eventually make it's way to these small gaps and get sucked in when extending the lens. Eventually you'll see the dust inside your lens on the interior of the glass. This cannot be fixed or remedied. In comparison, my Canon L 70-200 is sealed as is my 7D Mark ii and I can probably drop it in a river for second or two and not have any issues. You'll probably never see dust on the inside of an L lens for this reason. Older, cheaper lenses will show dust inside on the glass. Dust is not always visible in your pics but can affect optical performance if there is enough of it. My Tamron Experience with Support: After my first shoot and seeing the aberrations I took some examples and submitted a support ticket with Tamron. After a couple days they emailed me back and said they could correct the issue if I sent it in to be adjusted. Since the lens was only 2 wks old, they suggested I just return it to the seller (Amazon.) I did that and quickly received a replacement. Today I took some photos with the lens and while I will say, the chromatic aberrations are much less noticeable, but they are still there. This is also documented by professional reviewers if you check some of the online reviews. SUMMARY: This is a good lens, with an exceptional range 18-400 (28.8 - 640mm on a crop sensor non-full frame DSLR). Bokeh is not bad, images fairly clear, color reproduction good, and contrast decent. I didn't, and don't think others either, should expect this to replace your Pro lenses or fixed focal length lenses but it really is a good all-around lens. I hope I can keep it clean and dust free and expect to keep it for some time. I am not regretting my purchase. Attached photos - Images 1-3: Are of the 1st lens I received then returned showing obvious chromatic aberrations. Images 4-7: From 1st lens, various shots, processed, showing good qualities in the images Images 8-10: 2nd replacement lens showing some aberrations, but not as much as 1st lens.