Have you ever wondered which lens you used the most? Or what focal length is your favorite? The results of these queries can be used to decide what new lens to get; a (ultra)wide-angle, normal, or telephoto lens.
Well, there is an answer for both questions. The first (which lens) is relatively easy when you're using Adobe Photoshop Lightroom. Just select the metadata filter in the library view and examine the results.
Lightroom 2 - Metadata Overview
This doesn't show your favorite focal length (yet). If you're using (super)zoom lenses, like an 18-200mm, you'll be seeing a lot of photos taken with that lens. When you're shooting with primes only, you 'll probably get the results you wanted to see.
Lightroom (v2.5) doesn't show a brakedown of the focal lengths, so you need an additional piece of software to do this. If you're a Windows user there's ExposurePlot (Freeware). This program works its way through a directory structure and presents the results. The problem is that this program doesn't work on Apple OSX, so I (and lots of others) need something else.
Fortunately, the author of the excellent Lightroom GPS Plugin (Jeffrey Friedl) also created a Lightroom plugin called Data Plot. This plugin shows a breakdown of the focal lengths you use the most.
The following image shows the focal lengths I used with my Nikon D300 (photos taken over the last 2 years).
My data plot resultsThe graph shows that I shoot mostly at a wide-angle, but looking a bit further shows a decent perentage at the >70mm range (>2000 photos). This is caused by only three lenses; a 105mm macro, a 80-400mm, and a 70-200. This means that I'm shooting 2/3rds wide and 1/3rd tele(zoom).
This also means that the new AF-S Nikkor 24mm f/1.4G ED is (basically) completely justified to buy. I think.....