Zeiss 50mm f/1.4 IR-Planar and 85mm f/1.4 IR-Planar
See my June 3 notes on the Canon 5D Mark II converted for infrared use, as well as my Guide to Digital Infrared Photography for more on infrared photography, or any of my free articles on infrared.
The scene below makes a good test for hot spots and overall brilliance in infrared. Taken with the Zeiss 50mm and 85mm f/1.4 IR-Planars, which have special lens coatings for infrared transmission. Note the uniform illumination, absence of color shading, and absence of a bright central hot spot; the majority of lenses have troublesome issues here. It’s the special coatings that make the difference.
I’ll be taking the 25/2.8 IR-Distagon, 50/1.4 IR-Planar and 85/1.4 IR-Planar lenses with me to Yosemite this week, and I look forward to using these special lenses with Live View on my Canon 5D Mark II IR. Live View is very helpful in infrared, where backfocus can vary lens-by-lens.
Samples below handheld, processed with Canon DPP, Auto Levels, sharpened, that's it. False color can of course be converted to grayscale in a variety of ways, as I explore in my Guide to Digital Infrared Photography.