Links to Canon Lens Owner's Manuals in .PDF format are now included in most Canon Lens reviews. You will find the lens owner's manual link beside the first product image near the top of the page.
I added an aperture comparison to the Zeiss 35mm f/1.4 Distagon T* ZE Lens Review placeholder page.
I love the background blur a wide aperture lens can produce - and the Zeiss 35mm f/1.4 ZE Lens is one of the best wide-aperture lenses available.