Better late than never on Canon's recent non-L 70-300 offering:
http://www.lenstip.com/503.4-Lens_review-Canon_EF_70-300_mm_f_4-5.6_IS_II_USM_Image_resolution.html
TL/DR version:
- A
http://www.lenstip.com/503.4-Lens_review-Canon_EF_70-300_mm_f_4-5.6_IS_II_USM_Image_resolution.html
TL/DR version:
- Good but not stellar resolution; center looks 70-300L-ish, but it does not match up towards the outside of the frame. The 70mm wide open performance drops like a stone away from the frame center.
- Rave review of the nano USM: "the autofocus performance is sensationally fast. Running through the whole distance scale and confirming the focus at the shorter end of the focal lengths spectrum takes 0.1-0.2 of a second; for the longer focal lengths the process is by 0.1-0.2 of a second longer.
To be honest I am a bit surprised that, for the first time, such technology appears in completely amateur constructions. The working culture of the autofocus, its noiselessness, 100% accuracy, and superior speed put to shame even some professional lenses. A round of applause for Canon!"
- A