The D70 camera settings were:
JPG-Fine, aperture priority, Exposure Comp +1.0EV, ISO 200, WB Cloudy, AF-S, all images auto-focus, color mode Ia, Tone comp: Normal, Hue adjustment: 0 deg, Saturation: normal, sharpening: normal, shutter speed between 1/20th and 10 seconds depending on aperture. The tripod is a Bogen 3051 with a heavy pan/tilt head – a beast.
The 35mm was done first, then the 18-35mm then the 18-70mm were set to 35mm. I made sure the zoom lenses were at 35mm by shooting and adjusting the lens until the camera LCD indicated the lenses were shooting at 35mm. The light was becoming progressively more blue and only 2 minutes passed between lens tests. The test was done after the wall was in the shade. I used the histogram to try and make the exposures relatively equal. The 18-70mm required an higher exposure compensation of EV +1.3 because I’ve found my lens is off by -0.3EV.
f-stop 35mm f2D AF 18-35mm f/3.5-4.5D ED-IF AF 18-70mm f/3.5-4.5G ED-IF AF-S DX
f 2 N/A N/A
f 2.8 N/A N/A
f 4 (18-70 was at f4.2) N/A
Test images removed from site update
35mm Sharpness data
Using the JPG file size as an indicator of sharpness, several series of shots were taken with the 35mm f2 lens on a heavy Bogen 3051 tripod with matching pan-tilt head. The favorite subject, a brick wall, was used to conduct these tests. Between every series, the camera was refocused using autofocus. The camera body was made parallel to the wall to help eliminate depth of field reductions in the sharpness measurement.
From graph 1, it can be seen that my particular 35mm Nikon lens sample performs best at f11. These numbers cannot be compared against other lenses, as I do not have a baseline standard for comparison. This graph only provide information about the sharpness of my Nikon 35mm lens sample at various apertures. Lens sharpness rolls off at f16 and f22 due to diffraction, as expected. Note that the scale of the graph overemphasizes the relative reduction in sharpness. At full scale, there is not a huge sharpness difference.
Focus from 2 feet to 7 feet
Focus speed from infinity to infinity
The 35mm prime was strong at all apertures except f2, f16 and f22. There is a marked decrease in image sharpness from f16 to f22 on each lens, as is expected when the lens becomes diffraction limited. The 18-35mm never gets tack sharp when fully zoomed out, though it still performs well versus the 18-70mm. 35mm seems to be a sweet spot for the 18-70mm, too. If you would like to see the lens aperture affect in a progressive way, download each of the images above, put them into a folder and quickly flip through viewing them in Window Fax/Image viewer or Mac iPhoto. Using the flip-book technique is how I did my initial assessment of how each lens was performing.