Neocamera has a new tool for comparing lenses. The Compare Lens page can show side-by-side specifications of any number of lenses for DSLR or SLDs. Using it is extremely simple. Just keep selecting a Brand and Model for each lens you want to compare. When all the lenses to compare are listed, click the Compare button.
Compared lenses will appear side-by-side as in the Camera Bag, plus Neocamera will highlight comparable differences. Green means better, red means less good and the middle-of-the pack stays grey. Click through on the name or image of any lens to see its full specification and a list of comparable models for the same mount.
As always, comparing works best for similar lenses. Still, it is important to pay attention to the specifications which are not comparable such as the focal-range. Even for prime lenses, there is nothing inherently better about a 35mm vs 50mm one, they just give different perspectives. Zoom lenses are even more complex since someone may prefer a 24-70mm vs a 28-105mm and vice-versa, it mostly depends on the intended use.
Comparing the maximum aperture of prime lenses is simple but zooms show some interesting characteristics. A constant-aperture lens is usually considered better but this is not absolute. One may have a lens which has a F/3.5-4.5 maximum aperture compete against a constant F/4 lens, in which case we give a slight edge to the F/3.5-4.5 lens based on its capability to obtain a shallower depth-of-field, although using the constant F/4 lens is more convenient.
After making a comparison, sharing the results is easy. Simply copy the link from the Link To Results button and send it any way you like: email, Twitter, Facebook, etc. Here is an example link comparing popular bright zooms for Canon DSLR. Results look like this: