Review on Tamron 24 70Mm Zoom Nikon Mount by Maya Allen

Summary: Rugged, well built, bright, fast focusing, impressive vibration compensation and fairly compact compared to some of the competition BUT the built in autofocus is serious. Issue requiring calibration. For this reason, I rate the lens as follows: Before calibration: 2/5 stars (poor image quality out of the box) After calibration: 4+/5 stars (excellent image quality and excellent value for money) Overall rating: 3/5 stars (for requesting a custom calibration) The Tamron Lens Dock (Tap-In-Console) allows a high degree of control over the lens' autofocus settings. Using a high-quality focusing target, it took about an hour to understand the AF fine-tuning needed to auto-focus the lens. Measurements had to be taken at 24mm, 35mm, 50mm and 70mm for a 1.25ft, 3ft and 30+ft target - a dozen fixes with 10-20 test shots needed for each fix (100 total –200 shots). Test shots with camera settings for each test). The entire measurement process took a little over an hour. The measured AF-FT compensation values ranged from -12 to +14 and were dependent on focal length and distance. Don't expect to enter a single value into the camera to fix autofocus issues. With a tap-in console (not included with the lens I bought but available from some vendors) and software (downloadable) I can quickly enter a dozen corrections and store them in the lens (you can also update and change the lens firmware some other lens parameters). After the measurements were complete, entering new settings took only a few minutes, measuring the corrections was the tedious part. Not difficult. It just takes a lot of time. Whilst still testing, now that the lens is calibrated my first impression is that I am very happy with the image quality and would give it a tentative rating of 4+/5 stars after calibration. So if you don't mind AF calibration for the lens, read this as a 4+/5 rating and a *very* good score for an f/2.8 24-70mm lens after calibration. If you're counting on the lens to have sharp autofocus out of the box, read this as a 2/5 rating - seriously, just expect to have to calibrate it. Overall, the standard features (including ordering and waiting for the Tap-In Console to arrive) guarantee an overall rating of 3/5 stars due to the need for calibration.