Acapixus did a comparison of Canon EF 24-105/4.0 L IS USM versus a EF 28-105/3.5-4.5 USM and a EF 28-135/3.5-5.6 IS USM versus Canon EF 17-35/2.8 L USM versus Canon EF 50/1.4 USM versus Canon EF 100/2.8 USM macro.
The comparison was shot at ifferent focal length and at different f-stops using a Canon EOS 10D set at ISO 100. The camera was tripod mounted. Images were captured as RAW and converted to 24 bit TIFF files using DPP 1.503. Sharpness was set to 0 (no sharpening) and no other postprocessing has been applied to the images. 200×200 pixel crops were excised from the centre and periphery and saved as TIFF prior to conversion as JPEG files