Posts Tagged ‘James River’

Test shots: Pachydiplax longipennis exuvia

November 19, 2018

A Blue Dasher (Pachydiplax longipennis) exuvia was received from Andy Davidson, a graduate student at Virginia Commonwealth University.

Test shots of the specimen were taken using a relatively small aperture of f/20 for greater depth of field. Each photo is a “one-off,” that is, not a composite image. Focus stacks will be created sometime in the near future, after the exuvia is rehydrated and posed for better composition.

Extremely shallow depth-of-field is a common problem in macro photography. Depth-of-field increases as aperture decreases — in other words, they are inversely related. In this case, an aperture of f/20 was insufficient for the entire subject to be acceptably in focus so it will be necessary to create some focus stacks.

Also notice the background of the second photo looks darker and bluer than the first one. That was caused by the fact that the subject was farther from the front of the lens. There are work-arounds for this lighting problem, but hey, like the title of this blog post says these are “test shots.”

Related Resources

Tech Tips

The following equipment was used to shoot both of the macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. The camera was set for both manual exposure and manual focus. That’s right, a switch on the camera body is used to set the type of focus. It’s a Fujifilm thing. Actually, back-button focus was used to autofocus the image and adjusted manually as necessary. That’s also a Fujifilm thing.

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control a pair of off-camera Godox TT685 Thinklite TTL Flashes (TT685F and TT685C) set for radio slave mode. Each flash was fitted with a snap-on plastic diffuser.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen both images.

Copyright © 2018 Walter Sanford. All rights reserved.

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Test shots: Erythemis simplicicollis exuvia

November 16, 2018

An Eastern Pondhawk (Erythemis simplicicollis) exuvia was received from Andy Davidson, a graduate student at Virginia Commonwealth University.

This individual is a male, as indicated by the vestigial hamules visible on the ventral side of the exuvia, abdominal segments two and three (S2-S3).

Food for Thought

This exuvia is one of three “cast skins” from odonate nymphs that were collected in the field and reared in the laboratory as part of a research project entitled “Predator-Prey Interactions in a Changing World.” Since all three nymphs were collected from the James River rock pools, I assume they lived in essentially the same habitat. I wonder why the E. simplicollis exuvia is so much darker in color than either the P. flavescens or P. longipennis exuviae.

Related Resources

Tech Tips

The following equipment was used to shoot both of the macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. The camera was set for both manual exposure and manual focus. That’s right, a switch on the camera body is used to set the type of focus. It’s a Fujifilm thing. Actually, back-button focus was used to autofocus the image and adjusted manually as necessary. That’s also a Fujifilm thing.

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control a pair of off-camera Godox TT685 Thinklite TTL Flashes (TT685F and TT685C) set for radio slave mode. Each flash was fitted with a snap-on plastic diffuser.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen both images.

Copyright © 2018 Walter Sanford. All rights reserved.

Test shots: Pantala flavescens exuvia

November 14, 2018

A Wandering Glider (Pantala flavescens) odonate exuvia was received from Andy Davidson, a graduate student at Virginia Commonwealth University in Richmond, Virginia USA. Sincere thanks to Andy for sharing this beautiful specimen!

The exuvia is a “cast skin” from a nymph that was collected in the field and reared in the laboratory as part of a research project entitled “Predator-Prey Interactions in a Changing World.”

Test shots of the specimen were taken using a relatively small aperture of f/16 for greater depth of field. Each photo is a “one-off,” that is, not a composite image. Focus stacks will be created sometime in the near future, after the exuvia is rehydrated and posed for better composition.

Related Resources

Tech Tips

The following equipment was used to shoot both of the macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. The camera was set for both manual exposure and manual focus. That’s right, a switch on the camera body is used to set the type of focus. It’s a Fujifilm thing. Actually, back-button focus was used to autofocus the image and adjusted manually as necessary. That’s also a Fujifilm thing. For details, see “More Tech Tips” (below).

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control a pair of off-camera Godox TT685 Thinklite TTL Flashes (TT685F and TT685C) set for radio slave mode. Each flash was fitted with a snap-on plastic diffuser.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen both images.

More Tech Tips

Focus peaking can be activated when the camera is set for manual focus mode. Using back-button focus (AF-L button) in manual mode enables one to retain full control of the exposure triangle, focus quickly, and see what’s in focus before shooting a photograph. Fuji Back Button Focus (4:06), a YouTube video by Ashraf Jandali, provides a clear demonstration of how to use back-button focus on the Fujifilm X-T1.

Copyright © 2018 Walter Sanford. All rights reserved.

Russet-tipped Clubtail (terminal appendages)

August 14, 2017

Male Russet-tipped Clubtail dragonflies (Stylurus plagiatus) have a larger, more colorful club than females of the same species, their hind wings are “indented,” and their terminal appendages are shaped differently. Compare and contrast the appearance of males and females by looking at the following annotated images.

Male

Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”); and a lower unpaired epiproct (“inferior appendage”).

14 OCT 2016 | JMAWR | Russet-tipped Clubtail (male)

(See a full-size version of the original photo, without annotation.)

Notice the epiproct is a wide “plate” that spans both cerci, as shown in the full-size version of the preceding annotated image.

Female

All female dragonflies have a pair of cerci (superior appendages) that have little or no function. The hind wings of female clubtails are rounded.

21 AUG 2015 | Powhatan County, VA | Russet-tipped Clubtail (female)

(See a full-size version of the original photo, without annotation.)

The female Russet-tipped Clubtail dragonfly shown in the preceding image was spotted along the James River by my good friend Michael Boatwright, founder of the Virginia Odonata Facebook group. Sincere thanks to Mike for permission to use his photographs (background and inset).

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | male | top view
  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | female | top view
  • Genus Stylurus | Stylurus plagiatus | Russet-tipped Clubtail | female | side view

Copyright © 2017 Walter Sanford. All rights reserved.


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