Hi, I just bought a Sigma 150-600mm Contemporary lens. I need to figure out if it is defective or just needs to be calibrated. The lens has the latest firmware. I was shooting some bird photos and wound up with a lot of photos that looked slightly blurry. Here's one example: I've circled some areas that look like there's a ghosting defect that doesn't seem to be just focus. For a while I thought maybe I had some motion blur (and I might), but the shutter speed was 1/1600. I've been shooting with a handheld Canon 100-400mm + 1.4x, which has nearly the same magnification, and never had problem with motion blur. Well, I have the Sigma dock and the software for calibration, which seems to be a rather complex, time-consuming project. As I understand it, all this does is adjust the auto-focus; if I manually focus, the calibration is irrelevant. So I went outside today, found a car parked a long ways away and tried several manually focused shots. The setup was: Live view focusing with 10x mag Shutter speed 1/1250 Maximum aperture Camera on a tripod Optical image stabilization turned off Remote shutter release 10 second timer delay No wind Two shots for each attempt No AF adjustments in camera No AF adjustments to lenses (e.g. the lenses are as I received them) The combinations I tried were: Canon EOS 80D + Sigma @ 600mm Canon EOS 80D + Canon @ 560mm (400mm x 1.4) Canon EOS 70D + Sigma @ 600mm Here are the results. Each pair of shots is arranged vertically. Cameras and lenses change horizontally in the order above. Despite lower magnification, the Canon 100-400mm + 1.4x result seems a lot sharper and detailed than the Sigma on either camera body, particularly the bottom middle shot. The bottom left shot seems to show some ghosting on the "F" and "d" of "Ford". Can anyone confirm that: The manually focused shots using the procedure above are the best I'm going to get. No matter how I calibrate the lens, I'm not going to get anything better because calibration is only for autofocus. Thanks for any help. If there's something else I should check or any other tests I can try, let me know.