Often, in news groups, the question arises: How much sharpness degradation will I suffer if I switch to using one of the super zoom lenses available on the market?
In an effort to offer a tiny shred of evidence, I have shot the exact same scene with a Tamron 28-300 zoom and a Nikkor 80-400VR Zoom.
The two test shots, shown below, were both taken at 300mm, a shutter speed of 1/750 sec and an aperture of f/8. Auto-focus was used for both shots on a Nikon D100. The shots were taken with camera mounted on a tripod and the vibration reduction circuitry was turned "OFF" when the shot was taklen with the Nikkor lens.
With the exception of cropping, no post-processing was performed. No sharpening, no color changes were introduced. The images speak for themselves and I leave the viewer to reach his/her own conclusions. Be sure to note the license plate and it's bracket.
Tamron 28-300 Super Zoom
Nikkor 80-400VR Zoom
Last Updated: April 3, 2003