Archive for the ‘education’ Category

MYN – N. yamaskanensis exuvia (dorsal-lateral)

April 6, 2020

The following focus-stacked composite image shows a dorsallateral view of a Stygian Shadowdragon dragonfly (Neurocordulia yamaskanensis) exuvia collected by Freda van den Broek on 10 June 2019 along the St. Croix River in Interstate Park, Polk County, Wisconsin USA.

10 JUN 2019 | Polk County, WI | Stygian Shadowdragon (exuvia)

Notice the specimen has stubby mid-dorsal hooks along the length of its abdomen and lateral spines on abdominal segments eight (S8) and nine (S9).

Related Resources

Tech Tips

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

Four (4) photos were used to create the composite image, including a single photo focused on the head, thorax, and two places along the abdomen (S6-S7 and S9-S10).

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Focus Stacking using Adobe Photoshop

April 1, 2020

The following tutorial provides step-by-step instructions that can be used to create focus-stacked composite images with Adobe Photoshop (Ps).

First, download (from Google Drive) the two 16-bit TIFF files that will be focus-stacked. One photo is focused on the thorax, near the left eye; the other photo is focused on abdominal segment eight (S8).

Save the files to a folder on the desktop of your computer.

Open Photoshop.

  1. File / Scripts / Load Files into Stack… [Navigate to the folder on your desktop and select both files. By default, Ps creates a new document called “Untitled1.”]
  2. Select all layers. [Click on filenames, not icons.]
  3. Edit / Auto-Align Layers; Auto <OK>
  4. Edit / Auto-Blend Layers; Stack Images, Seamless Tones and Colors <OK>
  5. Duplicate layers to a new document. Layer / Duplicate Layers… / Document: New / Name: Backup-copy]
  6. Select “Untitled1”: Layer / Merge Layers (Ps merges all layers into one TIFF, named after the first file in sequence.)
  7. Straighten and Crop as necessary.
  8. Duplicate layer; append name with “Spot Healing.” [Remove dust spots, etc. from image using either Spot Healing Brush (Content-Aware) or Edit/Fill (Content Aware).
  9. “Sharpen” image. Duplicate top layer; append name with “HPF.” [Select top layer: Filter / Other / High Pass…; adjust until you can just see outline of image <OK>; change Normal to Overlay. 1.5 is a good starting point; decrease/increase as necessary. DO NOT OVERSHARPEN!
  10. File / Save As… TIFF; JPG.
  11. Select “Backup-copy.” File / Save As… Photoshop.

The composite image that you created should look like this, not including the copyright information shown in the lower-left corner of my image.

Take-aways

A two-photo focus stack works in part because the photos were shot using an aperture of f/16. Usually more than two “layers” are required to create a satisfactory focus-stacked composite image.

The same workflow can be used to create focus stacks using more layers with one caveat: more layers take more time for Photoshop to process.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

My MYN technique studio macro photography rig

March 25, 2020

The following annotated photos show the current iteration of my “Meet Your Neighbours” (MYN) technique studio macro photography rig, set up at BoG Photo Studio, Fairfax County, Virginia USA.

This rig represents the culmination of continuous experimentation spanning several months — it works well most of the time but not always. Some of the gear shown in the photos is nice but not essential. Start small and add items as necessary.

An equipment list and legend follows the photo set.

My MYN macro photography rig, front view.

Notice the orientation of the clear plastic stage relative to the white plastic background, optimized for best exposure of both the white background and the subject.

My MYN macro photography rig, side view.

Most of the essential gear is shown in the following photo. However you set up the rig, all you really need is a translucent white background, some sort of clear plastic stage, one or more radio-controlled external flash units (with light diffusers), and a camera, of course. I’m guessing many photographers will have most of the necessary equipment on-hand already.

Close-up of clear plastic stage and white plastic background.

In this case, the subject is a Common Green Darner dragonfly (Anax junius) exuvia collected by Mike Powell, my good friend and photowalking buddy.

Equipment List (Legend)

  1. light stand (Promaster Deluxe Light Stand LS-2n)
  2. white plastic background
  3. clear plastic stage [part of a repurposed sandwich box from a delicatessen]
  4. Godox TT685F (fill flash, stage right)
  5. Canon 580EX II Speedlite (fill flash, stage left) fitted with a “Vello Bounce Dome (Diffuser) for Canon 580EX II Flash
  6. Godox X1R-C
  7. Lastolite Ezybox Speed-lite 2
  8. Tether Tools articulating arm [A large articulating arm is useful but DO NOT BUY Tether Tools articulating arms — they’re OVERPRICED and either work poorly (like this one) or not at all (like a smaller one shown in one of my YouTube videos)! Articulating arms and clamps made by Manfrotto are the best albeit expensive; arms and clamps made by SmallRig are a close second at a modest price point.]
  9. Westcott Reflector Arm Extreme
  10. Godox TT685C (backlight)

Everything is mounted on a Promaster Deluxe Light Stand LS-2n using the following Manfrotto articulating arms and clamps (and more).

A collection of articulating arms and clamps makes it easier to position everything exactly where it needs to be, enabling quick and easy set-up, repositioning, and break-down.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

New use for Godox X1R-C

March 6, 2020

Recently I’ve been doing a lot of studio macro photography using a Godox X2TF (Wireless Flash Trigger for Fujifilm) mounted on my Fujifilm X-T1 digital camera with a Canon MT-26EX-RT Macro Twin Lite mounted on the pass-through hot shoe on top of the Godox X2TF.

This Rube Goldberg machine is big, heavy, and unstable sometimes, depending upon the camera angle relative to the subject.

Eureka!

I’ve been thinking about how I might move the Canon macro flash off-camera for studio photography. Then an idea occurred to me — maybe I could repurpose my Godox X1R-C (Wireless Flash Trigger Receiver for Canon) for use with the Canon macro twin flash in order to set- and trigger the macro flash by radio signal from Godox X2T-series and XPro-series radio flash triggers, or even another Godox TT685-series flash set for master mode.

Canon MT-26EX-RT (top) | Godox X1R-C (bottom)

Does it work?

During limited testing, the new off-camera flash rig works beautifully using either manual- or TTL modes. TTL works because the Godox X1R-C hotshoe features five contact pins in the same configuration as Canon Speedlites.

Product image courtesy B&H Photo.

I ordered some new articulating arms and micro clamps for positioning the Canon macro flash rig exactly where I want it during a photo shoot. Further testing will be conducted as soon as the new gear is delivered.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

MYN – S. plagiatus exuvia (ventral composite)

March 4, 2020

Russet-tipped Clubtail dragonfly (Stylurus plagiatusexuvia was collected by Joe Johnston on 17 July 2019 along Aquia Creek in Stafford County, Virginia USA.

17 JUL 2019 | Aquia Creek | Stylurus plagiatus | exuvia (ventral view)

Related Resources

Tech Tips

This specimen was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. I used the new variation on my old MYN studio rig and I’m still satisfied with the results.

Four photos were used to create a composite image: one photo focused on the thorax; and three other photos focused on abdominal segments two-three (S2-S3), seven (S7), and nine (S9).

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Stylurus plagiatus exuvia (composite)

March 2, 2020

Russet-tipped Clubtail dragonfly (Stylurus plagiatusexuvia was collected by Joe Johnston on 17 July 2019 along Aquia Creek in Stafford County, Virginia USA.

Two key field marks can be used to quickly identify both the genus and species of this specimen. Notice that abdominal segment nine (S9) is elongated, strongly suggesting this individual is a member of the genus Stylurus. The large dorsal hook of abdominal segment nine (S9) that overhangs segment 10 (S10) is a key marker for southern specimens of plagiatus.

Related Resources

Tech Tips

This specimen was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. I used the new variation on my old MYN studio rig and I’m still satisfied with the results.

Four photos were used to create a composite image: one photo focused on the head; and three other photos focused on abdominal segments five (S5), seven-eight (S7-S8), and 10 (S10).

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Unknown dragonfly exuvia (redux)

February 26, 2020

This blog post features more photos of an exuvia from an unknown species of odonate that was collected by Joe Johnston on 07 August 2019 along Aquia Creek at Channel Marker No. 34, Stafford County, Virginia USA.

The specimen is probably from either Family Corduliidae (Emeralds) or Family Libellulidae (Skimmers).

07 AUG 2019 | Aquia Creek | dragonfly exuvia (dorsal view)

The rule of thumb for differentiating Corduliidae exuviae from Libellulidae is as follows: It’s probably Corduliidae if the cerci are at least half as long as the paraprocts; it’s probably Libellulidae if the cerci are less than half the length of the paraprocts.

07 AUG 2019 | Aquia Creek | dragonfly exuvia (ventral view)

I’m having a hard time seeing the cerci clearly. If I’m seeing what I think I’m seeing, then the cerci are at least half as long as the paraprocts and the exuvia is from Family Corduliidae (Emeralds).

In order to verify my tentative identification, I need to use a higher magnification macro lens (such as my Canon MP-E 65mm Macro lens) in order to shoot a close-up view of the anal pyramid/terminal appendages (see inset diagram, lower-left corner).

Related Resource: MYN – Dragonfly exuvia (unknown species)

Tech Tips

This specimen was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. I used the new variation on my old MYN studio rig and I’m still satisfied with the results.

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Clubtail exuvia (possible G. vastus)

February 21, 2020

An odonate exuvia was collected from the concrete boat ramp at Riverbend Park, Fairfax County, Virginia USA. This individual is a member of Family Gomphidae (Clubtails), possibly Cobra Clubtail (Gomphurus vastus).

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

The first photograph was especially challenging to shoot. The camera viewpoint and the beam of light used to backlight the “stage” were at a nearly 90° angle, relative to each other, with the net result that the light level fell below pure white toward the background. The work-around that I used is less than elegant and needs to be refined. Any suggestions?

27 MAY 2017 | Riverbend Park | Clubtail exuvia (face-head-dorsal view)

Although the next photo appeared in my last blog post, this version was rotated slightly for a more pleasing appearance than the last iteration.

27 MAY 2017 | Riverbend Park | Clubtail exuvia (dorsal view)

The last photo is focused on the thorax in order to provide a relatively clear view of the prementum. Notice the specimen has a flat labium that doesn’t cover the face (not mask-like), as shown in the first photo. This field mark indicates the exuvia is from either Family Aeshnidae (Darners) or Family Gomphidae (Clubtails). Other field marks, including club-like antennae and the shape of the body, indicate this individual is a species of clubtail.

27 MAY 2017 | Riverbend Park | Clubtail exuvia (ventral view)

Related Resource: Gomphurus vastus exuvia, an identification guide by Walter Sanford featuring annotated images.

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Cicada exuvia

February 17, 2020

An Annual/Periodical Cicada (Family Cicadidae) exuvia was collected from a wooden kayak rack near the concrete boat ramp at Riverbend Park, Fairfax County, Virginia USA.

The specimen was photographed against a pure white background using the “Meet Your Neighbours” (MYN) technique.

27 MAY 2017 | Riverbend Park | cicada exuvia (face-head-dorsal)

Notice the proboscis between the cicada’s two large front legs, as shown in the preceding photo. I’ve seen zillions of cicada exuviae but never noticed a proboscis. Macro photography. It’s good thing!

27 MAY 2017 | Riverbend Park | cicada exuvia (dorsal view)

27 MAY 2017 | Riverbend Park | cicada exuvia (dorsallateral view)

27 MAY 2017 | Riverbend Park | cicada exuvia (dorsallateral view)

The proboscis is plainly visible in the following photo. (Look between the base of the two front legs.)

27 MAY 2017 | Riverbend Park | cicada exuvia (ventral view)

In situ Photographs

Which photo set do you thinks looks more interesting, the Meet Your Neighbours style photographs or the more traditional style of nature photography? In my opinion, the winner is clear!

Related Resources

What are the take-aways?

Based upon the table of “broods” featured in the Wikipedia page listed under Related Resources, I’m thinking the cicada exuvia that I collected during 2017 is more likely an annual cicada than a periodical cicada. For what it’s worth, no evidence of a mass emergence of cicadas was observed.

Copyright © 2020 Walter Sanford. All rights reserved.

Sexing odonate exuviae (Zygoptera)

February 12, 2020

For some (but not all) species of odonate larvae/exuviae, sex is indicated by either a rudimentary ovipositor (female) or vestigial genitalia (male). These sex organs don’t look exactly the same for all species of damselflies, but their function is identical.

The following photo gallery shows relatively clear examples that illustrate how to sex odonate exuvia in Suborder Zygoptera (Damselflies).

Female (rudimentary ovipositor)

Family Calopterygidae (Broad-winged Damselflies)

(none)

Family Coenagrionidae (Narrow-winged Damselflies)

11 MAR 2017 | Argia sp. | exuvia (female)

Family Lestidae (Spreadwings)

(none)

Male (vestigial genitalia)

Family Calopterygidae (Broad-winged Damselflies)

Family Coenagrionidae (Narrow-winged Damselflies)

(none)

Family Lestidae (Spreadwings)

(none)

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.


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