Something that you might come across when reading camera / lens reviews, or discussions, is talk about equivalent focal length and equivalent aperture. For example, a 50mm f/1.4 lens for a micro four thirds camera might be described as being a 100mm f/2.8 equivalent lens.
But what does this really mean? I have already discussed equivalent focal length in the article Photography Basics – Focal length, though I will cover it again very briefly in this article. But mostly I want to look at the idea of equivalent aperture, and how this relates to depth of field and the amount of light gathered.Read the rest of this entry »