Archive for the ‘digital photography’ Category

Macromiidae – It’s all about the “horn.”

September 24, 2021

A “horn” on the face-head is a characteristic field mark for odonate larvae/exuviae in the Family Macromiidae (Cruisers).

Look closely at the full-size version of each of the following photos and you should be able to see the horn on the face of a Stream Cruiser dragonfly (Didymops transversa) exuvia that was collected during mid-April 2021.

13 APR 2021 | PNC. William County, VA | Stream Cruiser exuvia (face-head)

It’s easier to see the horn in the next photo…

13 APR 2021 | PNC. William County, VA | Stream Cruiser exuvia (dorsal)

The horn is clearly visible in the last photo. Notice there are three “bumps” located between the eyes of the exuvia: the middle bump is the horn; the antennae bases are located to the left and right of the horn.

13 APR 2021 | PNC. William County, VA | Stream Cruiser exuvia (dorsal)

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Test shots: Didymops transversa exuvia

September 21, 2021

An exuvia from a Stream Cruiser dragonfly (Didymops transversa) was collected from one of the concrete abutments of a man-made dam located along a mid-size stream at an undisclosed location in Prince William County, Virginia USA.

I prefer to photograph odonate exuvia like this one “as is” — presumably its appearance is similar to the way larva looked when it lived underwater.

13 APR 2021 | PNC. William County, VA | Stream Cruiser exuvia (dorsal)

If so, then I’m guessing D. transversa larvae like to burrow in sediment, as indicated by the dirty dorsal side and relatively clean ventral side of this specimen.

13 APR 2021 | PNC. William County, VA | Stream Cruiser exuvia (ventral)

Post Update

The nymphs are sprawlers that cling to roots or hunker down in sediments of mixed sand and silt particles. Source Credit: K. J. Tennessen, Dragonfly Nymphs of North America, https://doi.org/10.1007/978-3-319-97776-8_10, Macromiidae, p. 330.

The Backstory

The preceding photos were shot using the prototype for a homemade curved clear plastic tray intended for staging subjects against a white background.

With a few minor tweaks, the curved stage performed better than during initial testing. I needed to add a second external flash unit to more evenly illuminate the white background.

Although I’m fairly satisfied with the results of these test shots, more testing is required to be sure the set-up is working the way I want.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Test shots

September 17, 2021

I have been working on the prototype for a homemade curved clear plastic tray that is intended for staging subjects against a white background.

My goal for Thursday: Test the prototype stage using a toy mini-lizard as the model for some test shots, and if the proof-of-concept were established, substitute an odonate exuvia for the toy lizard and shoot another set of photos.

16 SEP 2021 | BoG Photo Studio | toy mini-lizard

Well, you know what they say about the best laid plans! First, a line of fairly strong thunderstorms moved through the region where I live so I had to shut down my computer equipment. Second, the Washington Football Team played the New York Giants on Thursday Night Football so I had to watch the game. That’s right, had to watch. Turns out it was time well-spent.

Bottom line: I never finished the test shots of the toy lizard, and of course that means I didn’t shoot any photos of a real scientific specimen.

The curved surface of the clear plastic stage caused reflections from the single external flash that was used to light the subject. I had just figured out a work-around when the thunderstorms rolled in: I took 14 test shots; only the last one (shown above) is usable. I hadn’t intended to create a photo with a pure white background, but it was easy to adjust the image exposure during post-processing.

The Backstory

What’s my motivation? Many macro photographers use insect pins for mounting small subjects like odonate exuviae. I think there’s a big problem with that technique: The position of the pin is permanent. In other words, if the pin is attached to the ventral side of the specimen then it’s challenging at best and impossible at worst to take clean, clear shots of that side of the subject. I don’t want to use insect pins because some of my specimens are one of a kind.

For quite some time, I’ve been experimenting with the use of flat clear plastic stages as a solution for this problem. I think a curved stage might be a breakthrough, but more testing is required to be sure.

For example, notice the color fringing near the tip of the lizard’s tail — I’m not sure what caused that problem in only one part of the photo, therefore I don’t know how to fix it. Yet.

To be continued. Please stay tuned.

Copyright © 2021 Walter Sanford. All rights reserved.

Multimeter test results: GyroVu continuous power adapter for Panasonic

September 14, 2021

Eureka! I found my RadioShack Digital Multimeter.

In a recent blog post, I said I would like to use a multimeter to test the actual voltage output of the GyroVu USB TO PANASONIC DMC-GH2 (DMW-BLC12) BATTERY 40″ CABLE w/ 3.1A USB POWER SUPPLY that provides continuous power for my Panasonic Lumix DMC-FZ300 superzoom bridge camera. This blog post features the results from that test and more.

Panasonic rechargeable Li-ion camera battery

The Panasonic Lumix DMC-FZ300 uses a Panasonic DMW-BLC12 Rechargeable Lithium-Ion Battery (7.2V, 1200mAh), shown below.

Panasonic DMW-BLC12PP 7.2V Li-ion battery (front).

The positive and negative terminals of the battery are marked on the back of its case.

Panasonic DMW-BLC12PP 7.2V Li-ion battery (back).

I set the multimeter to measure voltage and touched the black test lead to the negative (-) terminal, then touched the red test lead to the positive (+) terminal. The LCD on the multimeter displayed a voltage of 07.29V, as shown below. That’s good!

Voltage output from Panasonic 7.2V Li-ion battery.

GyroVu continuous power adapter

Next, the GyroVu “USB Charger” (shown below, to the lower-left) was plugged in a 120V AC electrical outlet. The GyroVu dummy battery was connected to the 3100mA USB connector on the GyroVu USB Charger.

Although the positive and negative terminals of the dummy battery aren’t marked on its case, they are in the same places as on the Li-ion battery.

Once again I set the multimeter to measure voltage and touched the black test lead to the negative (-) terminal, then touched the red test lead to the positive (+) terminal. The LCD on the multimeter displayed a voltage of 08.36V, as shown below.

Voltage output from GyroVu dummy battery for Panasonic.

GyroVu says the output voltage of the dummy battery is 8.0V, so 8.36V seems to be within specs.

For what it’s worth, the Owner’s Manual for the model of RadioShack Digital Multimeter that I used specifies the accuracy of the multimeter is +/-0.8% of the reading, or in this case +/-0.07V.

Therefore I think it’s safe to say the GyroVu dummy battery has a slightly higher voltage than the Panasonic Li-ion battery. Is the higher voltage cause for concern?

Perhaps the more important question is whether amperage matters more than voltage. Regular readers of my blog might recall that I used my Drok USB Tester to measure an amperage of 0.45A drawn by the camera when it was connected to the GyroVu adapter and powered on. Is that amperage safe for the camera?

I’m not sure of the answer to either question, although I am certain further investigation is required.

Anker external power bank

Each GyroVu “dummy battery” adapter cable features a USB connector that can be used to connect your digital camera to an external power bank such as the Anker PowerCore+ 26800 PD 45W), shown below.

Product image courtesy AnkerDirect.

My Drok USB Tester was connected to one of two USB ports on the Anker power bank. The output voltage of the power bank was 5V, same as the GyroVu “USB Charger.”

The GyroVu dummy battery was plugged into one of two USB ports on the Anker power bank. Once again I set the multimeter to measure voltage and touched the black test lead to the negative (-) terminal, then touched the red test lead to the positive (+) terminal. The LCD on the multimeter displayed a voltage of 08.36V (shown above) — exactly the same as when I used the GyroVu “USB Charger” as the source of continuous power.

Voltage output for GyroVu dummy battery for Panasonic connected to Anker PowerCore+ 26800 PD 45W.

At this point I think it’s safe to say the Anker power bank is safe to use as a source of continuous power for my Panansonic Lumix DMC-FZ300 camera, that is, assuming the ~8.0V output of the GyroVu dummy battery isn’t a problem.

Related Resources

This blog post is one in a series of posts related to continuous AC power and long-lasting battery power for select Canon, Fujifilm, and Panasonic digital cameras.

Copyright © 2021 Walter Sanford. All rights reserved.

Anax junius versus Anax longipes

September 10, 2021

The following photograph shows the relative size of odonate exuviae from two species in the Genus Anax: junius; and longipes. Both specimens are from the Family Aeshnidae (Darners).

Relative size of exuviae from Anax junius versus Anax longipes.

The Common Green Darner dragonfly (Anax junius) exuvia was collected on 17 June 2021 from a small pond at an undisclosed location in Prince William County, Virginia USA.

The Comet Darner dragonfly (Anax longipes) exuvia was collected by Stanley Caveney on 19 July 2021 from a pond at MeadowWoods in West Elgin, Ontario, Canada.

Taxonomy

There are five species of dragonflies in the Genus Anax for the United States and Canada: Amazon Darner (Anax amazili); Common Green Darner (Anax junius); Comet Darner (Anax longipes); Giant Darner (Anax walsinghami); and Blue-spotted Comet (Anax concolor).

Common Green Darner and Comet Darner are the only species from the Genus Anax found where I live in Northern Virginia USA.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Post update: What is it?

September 7, 2021

Since I started exploring ways to provide continuous power for my digital cameras, I have been guided by two questions. 1. Will it work? 2. Is it safe? I watched a YouTube video recently that reminded me of the latter question.

External Power for Cameras, the Safest Options by Graham Houghton (14:53) inspired me to search online for an inline voltage meter with USB connectors.

Drok USB Tester

After watching several more YouTube videos, I decided to buy a Digital Meter USB Tester Multifunction Digital Voltmeter/Ammeter/Power Meter/Capacity Tester/Charger 5in1 USB Panel Meter, available from a company in the United States called “Drok.” The MSRP for the Drok USB Tester is $15.99. The one I ordered from the Drok Store on Amazon cost $9.99.

The device features one male USB connector for input, and two female USB connectors for output.

GyroVu continuous power adapter

The next photo shows a GyroVu USB TO PANASONIC DMC-GH2 (DMW-BLC12) BATTERY 40″ CABLE w/ 3.1A USB POWER SUPPLY. The device can be used to provide continuous power for my Panasonic Lumix DMC-FZ300 superzoom bridge camera.

The “USB Charger” — a small white power brick — was plugged into a 120V AC electrical outlet. Look closely at the full-size version of the following image. Notice the USB Charger output is 5V=3.1A. (3.1A = 3100mA.)

Testing the GyroVu continuous power adapter

The Drok USB Tester was connected to the 3100mA USB connector on the GyroVu USB Charger, shown above.

The USB cable for the GyroVu dummy battery was connected to “Output 1” of the Drok USB Tester; the dummy battery was inserted into the battery compartment of my Panasonic Lumix DMC-FZ300.

The last photo — the same one featured in my last blog post — shows the LED display on the front of the Drok USB Tester after my camera was powered on, indicating the output voltage of the USB Charger was 5V and the camera was drawing a current of 0.45A.

Panasonic Lumix DMC-FZ300 (121mm) plus Raynox DCR-250.

The output voltage of the GyroVu dummy battery is 8.0V so the “dummy” battery must contain a DC-to-DC step-up converter.

I plan to use a multimeter to test the actual voltage output of the GyroVu dummy battery, that is, as soon as I can find my RadioShack mulitimeter. (Someday I’ll get organized so I know where everything is!)

Sidebar: Deep Dive into Tech Specs

The Web page for the GyroVu continuous power adapter shown above says the product is for the Panasonic DMC-GH2 camera. How could I be sure the device would work with my Panasonic Lumix DMC-FZ300 digital camera?

The Panasonic Lumix DMC-FZ300 uses a Panasonic DMW-BLC12 Rechargeable Lithium-Ion Battery (7.2V, 1200mAh). Turns out that’s the same battery used by the Panasonic DMC-GH2. I know this thanks to Wasabi Power for providing a list of Panasonic cameras that use the DMW-BLC12 battery. (See the Web page for the PANASONIC DMW-BLC12 AC POWER ADAPTER KIT WITH DC COUPLER FOR PANASONIC DMW-DCC8, DMW-AC8 BY WASABI POWER, a product similar to the GyroVu continuous power adapter.)

Editor’s Note: The MSRP for the Wasabi Power continuous power adapter is $23.99 — nearly $10 less than the MSRP of $33.95 for the GyroVu USB Power Supply. You might be wondering why I didn’t buy the Wasabi Power device.

Notice the Wasabi Power device uses round connectors rather than USB connectors. I prefer the GyroVu devices because the USB connectors on their dummy batteries give me the flexibility to use them with my Anker PowerCore+ 26800 PD 45W battery as a power source for select Canon, Fujifilm, and Panasonic digital cameras that I own.

Related Resources

This blog post is one in a series of posts related to continuous AC power and long-lasting battery power for select Canon, Fujifilm, and Panasonic digital cameras.

Copyright © 2021 Walter Sanford. All rights reserved.

What is it?

September 3, 2021

Ladies and gentlemen, children of all ages. It’s time for another exciting episode of “What is it?”

If you think you know what is shown in the preceding photo, then please leave a comment. The answer will be revealed in a post update.

Editor’s Note: OK, OK — I realize this one is beyond challenging and might turn out to be impossible to identify correctly. But hey, take a guess anyway — you might be right!

Copyright © 2021 Walter Sanford. All rights reserved.

Previews of Coming Attractions – Fall Species of Odonates

August 31, 2021

There is an annual cycle of odonate activity that can be subdivided into three broad categories: Early Season (spring); Mid-season (summver); and Late Season (fall).

As we endure the “Dog Days of Summer,” waiting for the calendar to turn to fall, it’s time to begin looking for the Late Season (fall) species of odonates.

This blog post provides a photo sampler of some of the fall species of odonates that can be seen during September, October, and November in the Commonwealth of Virginia. This post is not intended to be a comprehensive field guide that features every odonate species that can be seen during the same time period.

Full Disclosure

Some fall species are easier to find than others. And some species are flyers rather than perchers, making it almost essential to capture them in flight using an insect net. That being said, it’s richly rewarding to find any of the rare to uncommon species so do your homework and be persistent. Good luck and happy hunting!


Editor’s Notes

Click on the date listed in the caption for each photo to see the original blog post for that image; click on the odonate name to see all of my blog posts related to that species.

Sincere thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for providing photographs of many of the rare to uncommon fall species of odonates featured in this photo sampler. Click on the word “Photo” in the caption for each of Mike’s photographs to see his original Facebook post for that image.

Every species features the following information: common name; scientific name; early-date/late-date; abundance; and habitat. All information is excerpted from “CHECKLIST OF THE DRAGONFLIES AND DAMSELFLIES OF VIRGINIA, April 2017 and April 2020 updates” by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage.


Dragonflies (Order Anisoptera)

Family Aeshnidae (Darners)

Black-tipped Darner (Aeshna tuberculifera)

Adult flight period: JUN 30 – OCT 29. Rare to uncommon. Habitat: Montane ponds.

Photo used with written permission from Michael Boatwright.

Common Green Darner (Anax junius)

Adult flight period: FEB 27 – DEC 30. Common. Habitat: Ponds.

Fawn Darner (Boyeria vinosa)

Adult flight period: JUN 03 – NOV 07. Common. Habitat: Streams, rivers.

Shadow Darner (Aeshna umbrosa)

Adult flight period: JUN 08 – DEC 05. Common. Habitat: Ponds, streams.

Family Corduliidae (Emeralds)

Clamp-tipped Emerald (Somatochlora tenebrosa)

Adult flight period: JUN 08 – OCT 15. Common. Habitat: Ponds, small streams.

Photo used with written permission from Michael Boatwright.

Fine-lined Emerald (Somatochlora filosa)

Adult flight period: JUL 10 – OCT 15. Rare to uncommon. Habitat: Boggy streams, swamps, marshes.

Family Gomphidae (Clubtails)

Arrow Clubtail (Stylurus spiniceps)

Adult flight period: JUN 13 – OCT 19. Uncommon to common. Habitat: Rivers.

Photo used with written permission from Michael Boatwright.

Laura’s Clubtail (Stylurus laurae)

Adult flight period: JUN 20 – SEP 26. Rare to uncommon. Habitat: Streams, rivers.

Photo used with written permission from Michael Boatwright.

Russet-tipped Clubtail (Stylurus plagiatus)

Adult flight period: JUN 15 – NOV 06. Uncommon to common. Habitat: Streams, rivers.

Family Libellulidae (Skimmers)

Autumn Meadowhawk (Sympetrum vicinum)

Adult flight period: MAY 28 – JAN 03. Common. Habitat: Ponds.

Blue-faced Meadowhawk (Sympetrum ambiguum)

Adult flight period: MAY 22 – NOV 19. Uncommon. Habitat: Swamps, ponds.

Black Saddlebags (Tramea lacerata)

Adult flight period: APR 12 – OCT 30. Common. Habitat: Ponds.

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

Spot-winged Glider (Pantala hymenaea)

Adult flight period: MAY 08 – OCT 20. Common. Habitat: Ponds.

A Spot-winged Glider dragonfly (Pantala hymenaea) netted at Saint Louis Catholic School, Fairfax County, Virginia USA. This individual is a female.

20 JUL 2016 | Fairfax County, VA USA | Spot-winged Glider (female)

Wandering Glider (Pantala flavescens)

Adult flight period: MAY 02 – NOV 17. Common. Habitat: Ponds.

Damselflies (Order Zygoptera)

Family Lestidae (Spreadwings)

Great Spreadwing (Archilestes grandis)

Adult flight period: JUN 25 – NOV 11. Uncommon. Habitat: Streams, ponds.

Spotted Spreadwing (Lestes congener)

Adult flight period: JUN 10 – NOV 11. Uncommon. Habitat: Ponds.

Photo used with written permission from Michael Boatwright.

 


Classification of Fall Species into Sub-groups

Migratory Species

At least five major species of dragonflies known to be migratory in North America.

  • Black Saddlebags (Tramea lacerata)
  • Common Green Darner (Anax junius)
  • Spot-winged Glider (Pantala hymenaea)
  • Wandering Glider (Pantala flavescens)

Rare to Uncommon Species

  • Arrow Clubtail (Stylurus spiniceps)
  • Black-tipped Darner (Aeshna tuberculifera)
  • Blue-faced Meadowhawk (Sympetrum ambiguum)
  • Clamp-tipped Emerald (Somatochlora tenebrosa)
  • Fine-lined Emerald (Somatochlora filosa)
  • Laura’s Clubtail (Stylurus laurae)
  • Ocellated Darner (Boyeria grafiana)
  • Great Spreadwing (Archilestes grandis)
  • Spotted Spreadwing (Lestes congener)

Copyright © 2021 Walter Sanford. All rights reserved.

Comet Darner dragonfly (exuvia)

August 27, 2021

An odonate exuvia from a Comet Darner dragonfly (Anax longipes) was collected by Stanley Caveney on 19 July 2021 at MeadowWoods in West Elgin, Ontario, Canada.

This specimen is from Family Aeshnidae (Darners), as indicated by the following field marks: the exuvia has a flat labium that doesn’t cover the face (not mask-like); the antennae are thin and thread-like (not club-like, as in Gomphidae larvae/exuviae); and the eyes are large relative to the size of the head.

19 JUL 2021 | Ontario, Canada | Comet Darner exuvia (lateral view)

Lateral spines along abdominal segments seven, eight, and nine (S7-9) indicate the genus is Anax; the length of the exuvia indicates longipes (~6 cm, measured as is).

The Backstory

Stanley Caveney is shown in the first of several photos taken by Hugh Casbourn. Stan contacted me for confirmation of his tentative identification of several Comet Darner exuviae that he collected during July 2021. Stan kindly gave one of the exuviae to me.

Photo used with written permission from Hugh Casbourn.

I asked Stan whether he had taken photographs of the Comet Darner exuviae in situ. Stan hadn’t, so he and Hugh revisited a local pond where they searched for and found two more exuviae.

How many exuviae do you see in the next photo? Look closely — both cast skins are shown in the same image.

Photo used with written permission from Hugh Casbourn.

An exuvia from a female Comet Darner appears in the foreground of the preceding photograph…

Photo used with written permission from Hugh Casbourn.

and a male Comet Darner appears in the background.

Photo used with written permission from Hugh Casbourn.

I asked Stan for advice regarding where to look for Comet Darner exuviae.

The six exuviae found to date were mainly at the inner edge of the cattail beds, facing the open water of the pond and where the individual cattail plants were spaced out. Source Credit: Personal communication from Stanley Caveney.

Related Resource: Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz. Refer to pp. 21-22.

Editor’s Note: Sincere thanks to Derek Caveney, Stan’s son, for shipping the exuvia to me. The specimen was packed so carefully that it arrived in excellent condition, as you can see in the first photo in this blog post. I’m looking forward to shooting a complete photo set of the exuvia.

Copyright © 2021 Walter Sanford. All rights reserved.

Yellow-sided Skimmer (terminal appendages)

August 24, 2021

Female and male Yellow-sided Skimmer dragonflies (Libellula flavida) were spotted at a small pond at an undisclosed location in Prince William County, Virginia USA.

Female

The first individual is a female, as indicated by her mostly yellow coloration and terminal appendages.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (female)

Female dragonflies have a pair of cerci (superior appendages) that have little or no function.

Mature male

The last individual is a mature male, as indicated by his light-blue pruinescence and terminal appendages.

17 JUN 2021 | PNC. Wm. County | Yellow-sided Skimmer (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”).

Immature male Yellow-sided Skimmers look similar to females of the same species. Terminal appendages can be used to differentiate the sex of immature males and mature females.

Related Resource: Yellow-sided Skimmer (male and female) – a blog post by Walter Sanford.

Copyright © 2021 Walter Sanford. All rights reserved.


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