MYN – Anisoptera exuvia (dorsal view)

An Anisoptera exuvia (species unknown) was collected by Mike Powell, my good friend and photowalking buddy. Although the exact date and location are unknown, we know the specimen was collected sometime during 2019 somewhere in Northern Virginia.

The specimen is definitely a dragonfly, probably from either Family Corduliidae (Emeralds) or Family Libellulidae (Skimmers), as indicated by its mask-like labium and thin antennae. Notice the row of mid-dorsal hooks located along several abdominal segments.

2019 | Anisoptera exuvia (dorsal view)

Related Resource: MYN – Anisoptera exuvia (species unknown). [Face-head-dorsal view of the same specimen featured in this blog post.]

Tech Tips

This subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

Three photos were used to create a composite image: one photo focused on the head; another focused on the mid-abdomen; and a third focused on abdominal segment 10 (S10).

For what it’s worth, the following camera settings were used to shoot all three photos: 100mm; ISO 100; f/8; 1/200 s; 0 ev. The power ratios for an array of four external flash units were as follows: Group A = 1/2 +0.3 (primary backlight); Group B = off (secondary backlight); Group C = 1/4 (subject, stage right); Group D = 1/16 (subject, handheld stage left).

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Anisoptera exuvia (species unknown)

An Anisoptera exuvia (species unknown) was collected by Mike Powell, my good friend and photowalking buddy. Although the exact date and location are unknown, we know the specimen was collected sometime during 2019 somewhere in Northern Virginia.

The specimen is definitely a dragonfly, probably from either Family Corduliidae (Emeralds) or Family Libellulidae (Skimmers), as indicated by its mask-like labium and thin antennae.

2019 | Anisoptera exuvia (face-head-dorsal)

Related Resource: MYN – Anisoptera exuvia (dorsal view). [Dorsal view of the same specimen featured in this blog post.]

Tech Tips

This subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

Three photos were used to create a composite image: two photos focused on the head; and another photo focused on the prementum. I must say I’m fairly pleased by the way the final image turned out, best appreciated by viewing the full-size version of the composite.

My Canon EOS 5D Mark II is a full-frame DSLR digital camera. RAW images are 5616 × 3744 pixels. The dimensions of the composite image are 5385 × 3657 pixels, that is, slightly smaller than full-frame. It’s usually necessary to crop composite images, at least a little, because the individual photos used to create the composite don’t align perfectly, even when the camera is mounted on a tripod (as it was in this case).

For what it’s worth, the following camera settings were used to shoot all three photos: 100mm; ISO 100; f/8; 1/200 s; 0 ev. The power ratios for an array of four external flash units were as follows: Group A = 1/16 (primary backlight); Group B = 1/32 (secondary backlight); Group C = 1/4 (subject, stage right); Group D = 1/8 (subject, handheld stage left).

I’m still searching for the “sweet spot” for this camera/lens combo. The white background was slightly under-exposed by approximately 1.5 stops, so I need to increase the flash power ratios for Group A and B. The subject was exposed almost perfectly, so Group C and D are close to spot on. Trial and error is the MYN way!

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Anisoptera exuvia (species unknown)

An Anisoptera exuvia (species unknown) was collected near a small pond at Occoquan Regional Park (ORP), Fairfax County, Virginia USA.

This individual probably is a member of the Family Libellulidae (Skimmers), as indicated by its anal pyramid. The small pond where the specimen was collected is perfect habitat for skimmers.

01 JUN 2019 | ORP | Anisoptera exuvia (dorsal–lateral view)

Related Resource: Another unknown species of odonate exuvia – a blog post by Walter Sanford featuring a “one-off” photo (that is, not a composite image) of the same specimen.

Tech Tips

This subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

Two photos were used to create a composite image: one photo focused on the head; and another photo focused on abdominal segments seven (S7) through nine (S9).

My Canon EOS 5D Mark II is a full-frame DSLR digital camera. RAW images are 5616 × 3744 pixels. The dimensions of the composite image are 5589 × 3743 pixels, that is, essentially full-frame. It’s usually necessary to crop composite images, at least a little, because the individual photos used to create the composite don’t align perfectly, even when the camera is mounted on a tripod (as it was in this case).

For what it’s worth, the following camera settings were used to shoot both photos: 100mm; ISO 100; f/8; 1/200 s; 0 ev. I need to tweak the settings a little in order to find the “sweet spot” for this camera/lens combo: the white background was slightly over-exposed; and the subject was slightly under-exposed. Of course that means I need to tweak the flash power for the backlights and add one or more additional external flash units for more fill flash. Overall, I’m fairly satisfied with the results of my first attempt using the MYN technique with this camera rig.

Copyright © 2020 Walter Sanford. All rights reserved.

Post update: Aeshna umbrosa exuvia

Male odonates have two sets of sex organs: primary genitalia located on abdominal segment nine (S9); and secondary genitalia located on abdominal segments two-to-three (S2-3).

Closer examination of some test shots of the following Shadow Darner dragonfly (Aeshna umbrosa) exuvia, photographed on 02 December 2018, showed both sets of vestigial genitalia are clearly visible on the ventral side of this specimen.

Shadow Darner (Aeshna umbrosa) | exuvia (lateral-ventral)

Aeshna umbrosa (mating pair)

All odonates (dragonflies and damselflies) have a 10-segmented abdomen, numbered from front to back. Male dragonfly secondary genitalia, called hamules, are located in segments two and three (S2 and S3); female genitalia in segment eight (S8). Male and female dragonflies form the mating wheel in order for their genitalia to connect during copulation.

A. umbrosa (in wheel). Photo used with permission from Patrick Boez.

Related Resource: Test shots: Aeshna umbrosa exuvia.

Copyright © 2020 Walter Sanford. All rights reserved.

Cordulegaster sp. larva (dorsal view)

This post features a focus-stacked composite image that shows a dorsal view of an odonate larva/nymph from the Family Cordulegastridae (Spiketails) that was collected and reared by Bob Perkins. The larva died before it metamorphosed into an adult.

Cordulegaster sp. larva (female) | dorsal view

Most larvae go through 10-13 stages of development known as “instars.” The author lacks sufficient experience to identify the instar of this specimen, although it appears to be one of the later stages as indicated by its well-developed wing pads.

Related Resources

• Test shot: Cordulegaster sp. larva
• Cordulegaster sp. larva (ventral view)

Tech Tips

12 photos were used to create the focus stack. A single focus point was positioned over select anatomical features; photos were taken at each point of interest.

The following equipment was used to shoot all of the photographs for the focus-stacked composite image, 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.

Auto power-off was disabled for the camera and all external flash units.

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

Copyright © 2019 Walter Sanford. All rights reserved.

Cordulegaster sp. larva (ventral view)

Bob Perkins collected and reared an odonate larva/nymph from the Family Cordulegastridae (Spiketails). The larva died before it metamorphosed into an adult.

This post features a focus-stacked composite image that shows a ventral view of the preserved larva; a composite image showing the dorsal view will be published in my next blog post.

Cordulegaster sp. larva (female) | ventral view

This individual is a female, as indicated by her rudimentary ovipositor that can be seen on the ventral side of the specimen along the boundary between abdominal segments eight and nine (S8-9). Do you see it?

Related Resources

• Test shot: Cordulegaster sp. larva.
• Cordulegaster sp. larva (dorsal view)

Tech Tips

Nine (9) photos were used to create the focus stack. A single focus point was positioned over select anatomical features; photos were taken at each point of interest.

The following equipment was used to shoot all of the photographs for the focus-stacked composite image, 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.

Auto power-off was disabled for the camera and all external flash units.

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

Copyright © 2019 Walter Sanford. All rights reserved.

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.

Copyright © 2019 Walter Sanford. All rights reserved.

Composite image: Shadow Darner dragonfly

Bob Perkins collected and reared a Shadow Darner dragonfly (Aeshna umbrosa) larva/nymph. This blog post features a focus-stacked composite image of a beautifully preserved specimen of the adult that emerged from the larva.

This individual is a male, as indicated by his “indented” hind wings.

Shadow Darner (Aeshna umbrosa) | face-head-dorsal

Artifacts

In my experience, focus stacking either works or it doesn’t. When it doesn’t work, “artifacts” appear in the final output that can be caused by many factors. There are work-arounds that can be used to repair the artifacts with mixed success. (See Tech Tips/Related Resources.)

I shot 19 photographs that were used to create a focus-stacked composite image of the Shadow Darner dragonfly. There’s a lot going on in those photos that caused too many artifacts to publish the final output. Several of the more noticeable artifacts are shown below.

Can you see three artifacts?

Artifacts highlighted.

I created another composite image; I used as many photos as I could before the first artifacts appeared. As it turns out, only five of 19 photos were used in the do-over composite image (shown at the beginning of this blog post). Look closely — some of the same artifacts are also noticeable in the do-over version.

Related Resources

• Test shots: Shadow Darner dragonfly.
• Test shots: Aeshna umbrosa exuvia.

Tech Tips

The following equipment was used to shoot the preceding composite image: Canon EOS 5D Mark II digital camera, in manual mode; Kenko macro automatic extension tubes (12mm, 20mm, and 36mm); 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.

Auto power-off was disabled for the camera and all external flash units.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the final output.

Tech Tips/Related Resources

• How to Focus-Stack Macro Images using Photoshop, by Don Komarechka.
• Stack it up — a guide to using the focus stacking photography technique
• Zerene Stacker Slabbing [The “Extreme Macro” Web site features lots of good resources.]

Copyright © 2019 Walter Sanford. All rights reserved.

Test shots: Shadow Darner dragonfly

Bob Perkins collected and reared a Shadow Darner dragonfly (Aeshna umbrosa) larva/nymph. This is a preserved specimen of the adult that emerged from the larva.

Test shots of this beautiful specimen were taken using a relatively small aperture of f/16 for greater depth of field. The following photo is a “one-off,” that is, not a composite image.

Shadow Darner (Aeshna umbrosa) | face-head

Related Resource: Test shots: Aeshna umbrosa exuvia.

Tech Tips

The following equipment was used to shoot the preceding photograph: Canon EOS 5D Mark II digital camera, in manual mode; Kenko macro automatic extension tubes (12mm, 20mm, and 36mm); 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.

Auto power-off was disabled for the camera and all external flash units.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

Focus-stacking with CamRanger

This blog post reports the result of more experimentation with completely automated focus stacking using CamRanger.

25 photos were used to create this focus-stacked composite image of an Eastern Least Clubtail dragonfly (Stylogomphus albistylus) exuvia from an odonate nymph that Bob Perkins collected and reared.

Eastern Least Clubtail (Stylogomphus albistylus) | exuvia (face-head)

I own two Canon macro lenses: a Canon MP-E 65mm Macro lens; and a Canon EF100mm f/2.8L Macro lens.

The MP-E 65mm macro is manual focus only, and cannot be used with CamRanger to create automated focus-stacked composite images.

In contrast, the EF100mm macro can be used with CamRanger to create automated focus stacks. In order to increase the magnification of the EF100mm macro, I used the lens in combination with three Kenko macro automatic extension tubes: 12mm; 20mm; and 36mm.

Pros and Cons

My goal was to create a tight close-up showing the face-head only. On one hand I failed to achieve my goal due to less maximum magnification using the combination of EF100mm macro lens and extension tubes rather than the MP-E 65mm macro lens.

On the other hand I shot 25 photos in a little more than four minutes^*, with the focus plane shifted in small increments from front to back along the subject — all without touching the camera after setting the initial focus point. That’s what I call success!

Related Resources

• More focus stacking with CamRanger
• Another foray into focus stacking

Tech Tips

The following equipment was used to shoot all of the photographs for the focus-stacked composite image of the exuvia: CamRanger hardware, and iOS app running on my iPad mini (with retina display); Canon EOS 5D Mark II digital camera, in manual mode; Kenko macro automatic extension tubes (12mm, 20mm, and 36mm); 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.

Auto power-off was disabled for the camera and all external flash units. CamRanger was set for a ^*10-second delay between shots in order to allow sufficient time for the lens to change focus automatically, the camera rig to settle, and the flash units to power-cycle.

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

Copyright © 2019 Walter Sanford. All rights reserved.