Page 1 - at-macro-flies

SOME FLY MACROS

Anthony Thomas
mothman@nbnet.nb.ca

Introduction & Equipment

I have an Olympus BH2-BHS trinocular microscope. With a 4x objective and a 2.5x NFK projection lens in the phototube
the maximum-length subject I can capture on my digital single-lens-reflex camera (DSLR) is 2.4 mm. As an entomolgist
with an interest in flies , 2.4 mm is far too small a field-of-view. I also have a so-called macro lens which connects
directly to the DSLR and will give me up to a 1:1 image on the camera’s sensor which translates to a 24 mm long subject
filling the frame. As most flies are larger than 2.4 mm and smaller than 24 mm in length, ‘pure’ microscopy and what can
be termed ‘standard 1:1 magnification-macro’ are severe limitations to obtaining high resolution images. The desired
magnification range is between 1x and 10x, a range which Johan J Ingles-Le Nobel includes in his term “Extreme-
Macro”.

Filling this magnification gap, i.e., 1x-10x, can be accomplished with a lens, or lenses, attached to a camera either
directly or with the addition of extension tubes or bellows (no microscope involved).There are several ways to achieve
such magnifications; see J Ingles-Le Nobel’s: http://extreme-macro.co.uk/ for an excellent comprehensive account
covering ‘everything’ you need to know.

At magnifications of 1:1 and greater, depth of field is very shallow, never enough to get the entire fly in focus. This calls
for a technique called "stacking" where several images, each at a different level of focus, are combined to give one fully-
focussed image. Nobel’s extreme-macro site also covers this subject.
The Flies
Animal species are grouped together based on similarities. The grouping is hierarchical. Thus animals with
exoskeletons and jointed limbs and placed in the Phylum: Arthropoda. Within the arthropods the animals are further
divided into Classes; e.g., crabs and lobsters are in the Class: Crustacea and bugs in the Class: Insecta. Within the
insects similar species are grouped into Orders; e.g., butterflies and moths are obviously different from flies, the
former are placed in the Order: Lepidoptera and the latter in the Order: Diptera. Again, within the Orders species are
grouped into Families. In North America there are 113 families of flies with many of these occurring locally here in
New Brunswick, Canada.
Viewed at greater than life-size, flies can be attractive and as such make ideal subjects for macrophotography. I
present here some images of the more attractive, and one atypical, flies found in New Brunswick, arranged by
families.