Saturday, June 23, 2012

D.O.F. and O.O.F.

click photo to enlarge
There seems to be some confusion surrounding the word "acronym". It is widely believed to be the use of consecutive initials. I've seen BBC and RSA so described. However, these are initialisms, "a group of initial letters used as an abbreviation for a name or expression, each letter or part being pronounced separately" (OED). An acronym is, "a word formed from the initial letters of other words" (OED). So, CIA isn't one because those three letters don't make a proper and pronounceable word, but AIDS certainly is (acquired immune deficiency syndrome). Confusion arises when we come to words such as radar (radio detection and ranging).  Isn't "radar", we might legitimately ask, almost but not quite an acronym, because it's an instance where the OED rule doesn't fully work? The fact is, that in the attempt to clearly define categories of words we've gone part way down the road to complete clarity by introducing ever more esoteric groupings, but have lost the value of a basic rule, not quite covered every eventuality, and sown more than a small degree of confusion. As this article shows.

Photography, like many other areas of special interest, is plagued by initialisms, acronyms and other kinds of abbreviations, to the extent that when I'm reading an article I sometimes feel the need for a glossary alongside me. It gets worse if you frequent photography forums because there you come up against all of this, but overlaid with examples of text-speak. One that has arisen in recent years is dof, DOF or D.O.F., meaning depth of field. (Whether we should continue to use full stops to indicate abbreviations or dispense with them, in the modern manner, is another subject for another day!) I think this has come about as people who have known only digital photography have moved from the once ubiquitous small sensor digicams to cameras with Four Thirds, APS-C and 35mm sensors. The depth of field of a small sensor is very big so oof (or OOF or O.O.F.), that is to say out of focus areas (also now called bokeh), are more difficult to achieve. With such cameras, if you want lens blur, you tend to have to either get very close to the subject or use a long telephoto. Larger sensors can achieve it in these ways too, but also by increasing the aperture. A consequence of all this is that shallow DOF shots have become very popular, so have large aperture lenses, and the value of a deep DOF - one of the challenges we sometimes struggled to achieve in the days of 35mm and larger film cameras - is currently less valued.

I was reflecting on this as I used my macro lens to take this very shallow depth of field shot of our oriental lilies. I photographed our white ones last year. This year we have red/brown and pink blooms as well as white. Out of the few shots I took this one intrigued me because the OOF areas resemble a liquid - perhaps pea soup - out of which the stigma and anthers are barely projecting.

photograph and text © Tony Boughen

Camera: Canon
Mode: Aperture Priority
Focal Length: 100mm macro
F No: f2.8
Shutter Speed: 1/80 sec
ISO: 125
Exposure Compensation:  +0.33 EV
Image Stabilisation: On