Find-that-website filter: Website with a unique explanation of lens focal length with respect to photography and zoom lenses. [more inside]
posted by odinsdream on Dec 24, 2008 - 7 answers

How "zoom" is a 55-200mm zoom lens? [more inside]
posted by Spurious on Sep 27, 2008 - 14 answers

I bought the Pentax K100D dSLR, partly on recommendations from here, and I love it. I have the 18-55 kit lens and the 50-200 zoom lens, which I mostly use. Now I would like to buy a faster in-between zoom, somewhere from 24-28 at the low end to 75-135 at the high end. I am trying to figure out whether to buy a Pentax, Tamron, or Sigma lens and am getting confused with all the contradictory reviews. The Tamron 24-135 is praised to the skies by some and trashed by others. I am leaning towards the Tamron 28-75 but would like something closer to 100 mm. Any advice?
posted by blue shadows on Nov 22, 2007 - 7 answers

What can I do with a "ruined" autofocus SLR zoom lens? Anything cool/neat I can turn it into? Any fun optics demonstrations I can do with the lenses inside? [more inside]
posted by kcds on Nov 20, 2007 - 5 answers

What would be a good alternative all purpose lens for a "professional amateur" photographer who has a Canon 20D, currently equipped with only an EFS 18-55 ? [more inside]
posted by hz37 on Jul 25, 2007 - 19 answers