This page evaluates a second brand-new sample of the 100/2.8L IS. Like the first sample, it has an optical alignment problem, though the problem is considerably muted compared to the first awful sample.
In field shooting, I observed some unexplained sharpness across the frame, which I first dismissed (mentally) as field curvature of variations in focus. Still, an uneasy sense remained that something was amiss.
I set up a careful tripod comparison on my best outdoor test target: a detailed mosaic at Stanford’s Memorial Church. For the 100/2.8L, image stabilization was disabled, and my usual careful protocol involving mirror lockup was used. I shot the lenses three times each, refocusing each time.
The camera was angled just slightly up, an intentional device to help reveal the plane of actual focus. Foreground and backup (top) help also in analysis. Focus was on the two pink flowers near center. Lighting was dull overcast and no attempt was made here to spiff up the results.
Article continues for subscribers...
If you’re already a subscriber, CLICK HERE TO LOG IN
diglloyd Advanced Photography includes hundreds of pages of exclusive coverage and high resolution, Retina-grade example pictures detailing Canon and Nikon DSLR bodies and their lenses, with in-depth analysis of sharpness and contrast, color, bokeh, vignetting, distortion, MTF, and flare. Also included is a wealth of in-context technique and workflow insight. Since 2006, diglloyd Advanced Photography is the authoritative review and on-line reference for discerning Canon and Nikon shooters. Subscriptions cost $ per year.