Review on Irix 150mm f/2.8 Macro 1:1 Dragonfly Lens for Canon: Unleash Your Macro Photography Potential by Brad Knierim

I use with Sony A7R iii adapter and Sigma MC-11. Both the camera and the adapter have the latest firmware. I like the feel of the lens. Focusing is made easier by using the viewer's magnification instead of focusing. The pictures taken are pretty good. But I experience the loud buzz that others have reported. The buzzing would occur every time the camera was turned off, but sometimes the buzzing would be random when the power was turned off. I encountered the issue in both manual and aperture priority modes of the camera, and with SteadyShot on and off. You have to take the battery out to keep it from buzzing. Interesting: if I have SteadyShot off and there is a buzzing, SteadyShot turns on when I turn on the camera. I have submitted my "test" results to Irix and they cannot be reproduced. Final Word from Irix (November 22nd) You looked at the firmware version of my lens. I'd like to keep the lens for both its focal length and macro ability, but I'm concerned that either the camera or the lens will be damaged. I will update this review as I learn more from Irix. Update 12/19/19: Yesterday I updated the camera firmware to the recently released version 3.1. After the update, the hum problem no longer occurred. I followed my previous testing steps. I'm also updating the rating to 4 stars (the rating would be 5 stars if it weren't for the buzz issue). Update May 2020 – The buzz problem is back. On a whim I removed the MC-11 adapter and added a Commlite adapter. No problems with hum in the last 4 months