Common photography myths (13)

Myth #12: Medium format lenses have a higher resolution than 35 mm lenses

September 5th, 2009 - 08:46:36 PM:

Bad news: most often the opposite is true. Most medium format lenses have a smaller resolution than comparable lenses for the 35 mm format. The good news is that the larger film format more than makes up for the smaller resolution.

For example, when a 35 mm lens can resolve 80 lp/mm (line pairs per millimeter), it can resolve 2880 lp over the width of a 35 mm frame. A medium format lens only needs to resolve about 50 lp/mm to project 2800 lp onto its 56 mm wide frame. If it can resolve between 50 and 80 lp/mm, it can resolve more lp on its frame than a 35 mm lens on a 35 mm frame.

Because of the typically lower resolving power of medium format lenses it also makes little sense to adapt these lenses to 35 mm cameras, at least when you try to gain resolution. These adapters only combine the disadvantages of both systems. By using medium format lenses you can only gain resolution by also using medium format cameras.

There are a number of general statements about photography passed off as “the truth”. They are repeated again and again in introductory texts about photography and on the Internet. Repetition, however, doesn't make a false statement true. Here are the most common myths I've encountered: