Tamron 28-300mm F/4-7.1 Di III VC VXD Sony E

Mount Sony E-mount var acc = document.getElementsByClassName("accordion"); var i; for (i = 0; i< acc.length; i ) acc i.addEventListener("click", function() this.classList.toggle("active"); var panel = this.nextElementSibling; if (panel.style.display === "block") panel.style.display = "none"; else panel.style.display = "block"; ); Length is the distance from the front end of the lens to the lens mount face.
The circular diaphragm stays almost perfectly circular up to two stops down from maximum aperture.