Wallace Koopmans Artlog

Back in the early 1980’s the Olympus XA was quickly adopted by many photographers as a pocket camera for many reasons.  It was small and pocketable but it also produced good results.  This of course is due to the lens which is made using 6 elements in 5 groups.  (That’s where the F Zuiko comes from, F is the 6th letter in the alphabet E would denote 5 elements and G would be 7).  The lens focusing is done not with the front element as is particularly familiar with small film cameras but is done using internal elements.  The electronically controlled shutter  also sits between lens elements.  The shutter operates all the way from 10 seconds to 1/500sec so properly secured the XA can be used for relatively long exposures.

The rangefinder focusing can be a little fiddly with the XA and its small focus lever in the center just bellow the lens but it works.

Have you ever wondered why it can be so difficult to achieve focus on close subjects?  Bellow is some of the Olympus XA’s depth of field at different apertures presented graphically.

The yellow area represents the closest and furthest distance that is reasonably in focus for any given aperture when focused at the minimum distance of 2.8ft. You can see that increasing the aperture does not have the same increase in depth of field as it would if the lens is focused at a further distance.  Contrasting this when the lens is focused at 12feet an increase in aperture can have a dramatic impact on depth of field.  An example is at f5.6 and 12feet  the area considered to be in focus is from about 7.7ft to 27.5ft but simply stopping down to f8 yields 6.7ft to 62ft.

This is how fixed focus cameras work they are set to a certain distance of focus and an aperture that provides enough depth of field.  Similarly this is what you are doing with zone focusing and again why that can be so difficult when you cant control the aperture and the camera to subject distance is short.

Olympus considers the XA as one of its technological milestones for its online camera museum.  Olympus Museum Cameras XA