More composite images: P. obscurus exuvia

The following focus-stacked composite images show dorsal- and ventral views of the exuvia from a Common Sanddragon (Progomphus obscurus) larva that was collected and reared by Bob Perkins.

Common Sanddragon (P. obscurus) | exuvia (dorsal)

Here are some personal observations after examining the specimen carefully.

Large eyes, shaped like Crescent Moons (as seen in face-head view).
Hairy antennae.
Lateral spines on abdominal segments five through nine (S5-9).
Dorsal hooks on S2-9: prominent on S2, less prominent on S3; vestigial on S4-9.
“Shoulder pads” on thorax.
Cerci approximately one-third as long as paraprocts; epiproct and paraprocts about equal in length.

Common Sanddragon (P. obscurus) | exuvia (ventral)

The front- and middle legs block the mentum (prementum). This specimen is a good candidate for rehydrating the exuvia and reposing its legs.

Related Resource: Composite image: Progomphus obscurus exuvia.

Tech Tips

Six (6) photos were used to create the first focus stack; seven (7) photos were used for the second. A single focus point was positioned over select anatomical features, working from back-to-front; photos were taken at each point of interest.

The following equipment was used to shoot all of the photographs for the two focus-stacked composite images, shown above: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tube; Canon EF100mm f/2.8L Macro lens (set for manual focus); and Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and several external flashes set for “Slave” mode including Canon 580 EX- and Canon 580EX II Speedlites and a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Adobe Photoshop CC 2017 was used to create the focus-stacked composite images, as well as spot-heal and sharpen the final output.

Tags: cerci, Common Sanddragon dragonfly, dorsal hooks, epiproct, exuvia, gear talk, high-speed sync, larva, lateral spines, paraprocts, Progomphus obscurus, studio photography

This entry was posted on February 6, 2019 at 4:00 am and is filed under Aperture, Canon 580EX II Speedlite, Canon 580EX Speedlite, Canon EF 100mm Macro lens, Canon EOS 5D Mark II, Canon MT-26EX-RT Macro Twin Lite, digital photography, dragonflies, education, extension tubes, Godox TT685C, How To, Lastolite flash modifier, macro photography, natural science, Photoshop, wildlife photography. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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