The new MTF Comparison Tool
has just received 4 additional chart types. Joining the Average and Variance charts are the 2D Map
and 3D Isometric charts
in 10 lp/mm and 30 lp/mm formats.
Among the additional lenses loaded into the tool are the 24-70mm f/2.8 zooms
(Canon, Nikon and Sigma). Remember that CA is generally more prevalent in zoom lenses (especially in the maximum focal length extents) and that CA is a significant factor in corner MTF performance (and is generally an easy-to-correct aberration). If you see chart lines/colors showing decreasing MTF measurements toward the corners (right side or periphery), CA may be at least some of the cause. Reference the Lens Image Quality Tool
to see if CA is a significant component of a dropping MTF chart measurement for a specific lens.
One of the zoom lens additions is the new Sigma 24-35mm f/2 DG HSM Art Lens
. Of note is that, while the tool says "Average" for the chart type, only one copy of this lens was available for MTF testing. The test results will be updated (and the other chart types added) when a larger sample size is available. B&H
has the Sigma 24-35mm f/2 DG HSM Art Lens
There are enough results in the MTF tool to entertain for hours. Here is a comparison that I find interesting
. While these are not equivalent apertures (one stop apart), B&H
has the Zeiss 135mm f/2 Lens
in stock with a $300 instant rebate bringing the price down to far less than half that of an Otus.
Be sure to share the MTF tool with your friends!