Posts Tagged ‘exuvia’

Odonate exuviae collecting sites

July 29, 2019

The following video shows a “boater’s-eye view” of some sites where odonate exuviae have been collected by Joseph Johnston along Aquia Creek, located in Stafford County, Virginia USA. Joe is an avid boater and sport fisherman who kindly agreed to be my “Eyes on the Aquia,” always on the lookout for odonate exuvia to share with me.

The first photo gallery features still images of several spots shown in the preceding video. Joe estimates the water is ~5-6 feet deep outside the channel markers, and much deeper in the middle of the creek.

Joe’s boat is somewhere between the long boat docks (lower-right quadrant) and Government Island (near center), as shown in an aerial view of Aquia Creek provided by Google Maps.

The last photo gallery features still images of several exuviae, shown in situ before Joe collected the specimens. The first photo shows where it all began, when Joe collected his first dragonfly exuvia for me on 20 June 2018.

Related Resources

Credits

All media Copyright © 2019 by Joseph Johnston. Used with permission from Mr. Johnston.

Copyright © 2019 Walter Sanford. All rights reserved.

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Dromogomphus spinosus exuvia

June 28, 2019

A dragonfly exuvia was collected by Joe Johnston on 22 May 2019 at Aquia Creek, Stafford County, Virginia USA. This specimen is the cast skin from a Black-shouldered Spinyleg (Dromogomphus spinosus) larva. D. spinosus is a member of Family Gomphidae (Clubtails).

Black-shouldered Spinyleg (Dromogomphus spinosus) | exuvia (dorsal)

At first I thought the exuvia might be a species from the genus Stylurus, based upon the mid-dorsal spine on abdominal segment nine (S9). After careful examination of two excellent photo-illustrated PowerPoint presentations by Kevin Hemeon at NymphFest 2016 (see Related Resources, below), I noticed none of the species in the genus Stylurus have dorsal hooks. That’s when I realized the specimen must be D. spinosus. Eureka!

Related Resources

The following PowerPoint presentations by Kevin Hemeon are available in the “Files” section of the Northeast Odonata Facebook group. Direct links to the documents are provided below.

The Backstory

Joe Johnston is an avid boater and sport fisherman who kindly agreed to be my “Eyes on the Aquia,” always on the lookout for odonate exuvia to share with me. On 22 May 2019 Joe caught a largemouth bass that swam around one of the wooden pilings of a boat dock that extends far into Aquia Creek. The fishing line was snagged on the piling so Joe moved his boat into position to free the fish. That’s when he noticed the exuvia clinging to a piling on the underside of the dock. Good catches, Joe!

Tech Tips

The following equipment was used to shoot the quick-and-dirty handheld macro photograph featured in this post: Fujifilm X-T1 digital camera; and Fujinon XF80mm macro lens plus lens hood. 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. Camera settings: focal length 80mm (120mm, 35mm equivalent); ISO 200; f/9; 1/180s.

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control an off-camera Godox TT685 Thinklite TTL Flash (TT685F) set for radio slave mode. The flash was fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen the image, plus add annotations.

Sometime in the future (probably the odonate “off-season”) I will create higher quality composite images of this exuvia, shown from all viewpoints including the ventral view. As it turns out, the dorsal view is sufficient to identify this species.

Copyright © 2019 Walter Sanford. All rights reserved.

Stonefly exuvia

March 20, 2019

A Stonefly (Order Plecoptera) exuvia was spotted clinging to the boat ramp at Riverbend Park, Fairfax County, Virginia USA. This specimen is approximately 1.5 inches in length.

28 JUN 2017 | Riverbend Park | Stonefly (Order Plecoptera) exuvia

Now I know the identity of the unknown species of aquatic insect that photobombed my photographs of Harpoon Clubtail (Phanogomphus descriptus) and Lancet Clubtail (Phanogomphus exilis), taken at another location a few weeks before the preceding photo.

Related Resources

Credits

Sincere thanks to Jacklyn Gautsch and Graham Floyd, members of the BugGuide Facebook group, for help in identifying this exuvia.

Copyright © 2019 Walter Sanford. All rights reserved.

More composite images: P. obscurus exuvia

February 6, 2019

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

Here are some personal observations after examining the specimen carefully.

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 tubeCanon 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: Progomphus obscurus exuvia

February 4, 2019

The following focus-stacked composite image shows the exuvia from a Common Sanddragon (Progomphus obscurus) larva that was collected and reared by Bob Perkins.

I have 10s, maybe 100s, of Common Sanddragon exuviae in my collection, but have never seen one cleaner than this beautiful specimen. I didn’t realize P. obscurus larvae are so hairy!

Related Resource: More composite images: P. obscurus exuvia.

Tech Tips

11 photos were used to create the focus stack. 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 the preceding composite image: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (set for f/11 at 3x); 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 stack, as well as spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

More test shots: Ladona deplanata exuvia

January 16, 2019

As promised, this blog post features more test shots of the exuvia from a Blue Corporal dragonfly (Ladona deplanata) larva/nymph collected and reared by Bob Perkins.

All of the images in this photo set (including the dorsal view featured in my last blog post) are underexposed, except for the following photo: this photo looked overexposed on my camera LCD; the rest of the photos looked fine.

In reality, the photos were underexposed because I didn’t compensate for the effect of the extension tubes on exposure — a problem that was probably caused/exacerbated by switching the ISO from my usual setting of “A” (Auto) to 200. This photo turned out to have the best exposure because the flash power was several stops higher than the rest of the photos in the set. Remember the exposure triangle. (See Tech Tips/Related Resources, below.)

Oh, so close to a good shot! The left front leg blocks part of the face-head, and that doesn’t work for me. This specimen is a good candidate for rehydrating the exuvia and reposing its legs.

Related Resource: Test shot: Ladona deplanata exuvia.

Tech Tips

The following equipment was used to shoot the preceding photo: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 and MCEX-16 extension tubes; Fujinon XF80mm macro lensGodox XProF TTL Wireless Flash Trigger for Fujifilm camerasGodox TT685F Thinklite TTL Flash for Fujifilm CamerasGodox TT685C Thinklite TTL Flash for Canon Cameras fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier; and Canon 580EX II Speedlite mounted on a Godox X1R-C TTL Wireless Flash Trigger Receiver for Canon.

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

Tech Tips/Related Resources

What you should remember, as a rule of thumb, is that by the time you get close to magnifications of 1:1, the effective f-stop of the lens will have changed by about 2 stops. That means you, or your camera, are needing to compensate for this with a higher ISO, or a shutter speed that’s 4-times longer than you’d need without those tubes.

Copyright © 2019 Walter Sanford. All rights reserved.

Focus-stacking with CamRanger

January 7, 2019

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.

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

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.

Five-flash studio macro photography rig

January 4, 2019

This blog post is a follow-on to a previous post entitled Studio macro photography rig. As you can see, my four-flash rig has been updated to include a fifth flash: a Godox TT685C Thinklite TTL Flash fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier.

Although it isn’t shown clearly in the following quick-and-dirty photo taken with my iPad 3, both the Godox TT685C and a Canon 580EX II Speedlite are mounted on the crossbar of my Vanguard Alta Pro 263AB 100 Aluminum Alloy Tripod. Look closely — the tiny subject (a Stylogomphus albistylus exuvia) is positioned in the far-left corner of the white posing platform, in front of the Lastolite flash modifier.

The Lastolite flash modifier features a two-layer system of diffusers that provides beautiful soft light: the white square you can see on the outside of the collapsible box and another white square that you can’t see, located halfway between the flash head and the front of the box.

Another addition to the rig is my new 3 Legged Thing QR11-LC Universal L-Bracket. (Note: The camera body blocks your view of the L-bracket.) The L-bracket enabled me to mount the camera in portrait mode quickly and securely. Although the Manfrotto 405 Pro Digital Geared Head can be adjusted to position my camera rig in portrait mode, the heavy camera-lens-flash combo is unstable and can tip over easily.

New gear used for studio macro photography.

By the way, in case you looked at the preceding photo and wondered “What’s up with the crazy crop?” I used Photoshop to conceal some of the clutter in my kitchen. I set up my macro photo rig in the kitchen because it’s the largest uncarpeted area in my tiny apartment. Padded carpet is a poor surface for macro photography — the field of view from a tripod-mounted camera-lens-flash combo shifts noticeably (and unacceptably) as one moves around the rig.

More Tech Tips: A complete description of all of the equipment used in my studio macro photography rig is provided in a previous blog post entitled Studio macro photography rig.

Copyright © 2019 Walter Sanford. All rights reserved.

Top 10 Photos of 2018

January 2, 2019

The following gallery shows 18 finalists for my “Top 10 Photos of 2018.” The photos are presented in reverse-chronological order beginning in September 2018 and ending in February 2018.

No. 1

20 SEP 2018 | Fairfax County, VA | Pandora Sphinx moth

No. 2

23 AUG 2018 | Occoquan Bay NWR | Osprey (male, plus prey)

No. 3

No. 4

No. 5

No. 6

05 JUL 2018 | Fairfax County, VA | Sable Clubtail (female)

No. 7

No. 8

No. 9

12 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

No. 10

08 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

No. 11

06 JUN 2018 | Northern Virginia | Gray Petaltail (male)

No. 12

No. 13

No. 14

No. 15

No. 16

No. 17

No. 18

Editor’s Note: The following location codes are used in some photo captions, shown above.

Copyright © 2019 Walter Sanford. All rights reserved.

More test shots: Stylogomphus albistylus exuvia

December 21, 2018

This blog post features another focus-stacked composite image of an Eastern Least Clubtail dragonfly (Stylogomphus albistylus) exuvia from an odonate nymph that Bob Perkins collected and reared.

11 photos were used to create this focus stack. My camera is set for spot focus, meaning one-area focus for each photo. A single focus point was positioned manually somewhere on the face-head in all 11 photos.

From this viewpoint, the large, dish-shaped antennae remind me of wooden spoons (with short handles).

This is the first time I shot some photos in portrait mode using my new 3 Legged Thing QR11-LC Universal L-Bracket (Orange) mounted on my Canon 5D Mark II DSLR camera. I’m sold!

3 Legged Thing QR11-LC Universal L-Bracket (Orange).

Related Resources

Tech Tips

The following equipment was used to shoot all of the photographs for the focus-stacked composite image of the exuvia: Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tubeCanon 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 image, as well as spot-heal and sharpen the final output.

I used my Panasonic Lumix DMC-FZ150 superzoom camera and a handheld Canon 580EX Speedlite fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier to shoot the photo of my Canon 5D Mark II.

Copyright © 2018 Walter Sanford. All rights reserved.


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