Non-stop flight

April 22, 2017

On 18 April 2017, a Common Baskettail dragonfly (Epitheca cynosura) was spotted patrolling part of the shoreline at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male, in flight.

108mm (600mm equivalent) | ISO 100 | f/5.2 | 1/800s | -1 ev | flash fired

The photograph was taken using a Panasonic LUMIX DMC-FZ150 superzoom bridge camera and a Canon 580EX Speedlite external flash set for manual mode at 1/8 power and 105mm zoom.

Related Resource: Stop-action photography of dragonflies in flight, a blog post by Walter Sanford, featuring Phil Wherry’s answer to my question “How fast would the camera shutter speed need to be in order to freeze all motion of a dragonfly in flight?”

Copyright © 2017 Walter Sanford. All rights reserved.

Phanogomphus

April 20, 2017

Two teneral dragonflies were observed near Mulligan Pond during a photowalk at Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. I was able to photograph the first one I spotted; the second flew away as soon as I approached it.

This dragonfly is either Ashy Clubtail (Phanogomphus lividus) or Lancet Clubtail (Phanogomphus exilis). Based upon the short, faded yellow markings on the dorsal side of abdominal segments eight and nine (S8-9), this individual is probably an Ashy Clubtail dragonfly. Less reliably, the 18 April date of the spotting also suggests Ashy Clubtail (for Northern Virginia).

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

Both Ashy- and Lancet Clubtail dragonflies were formerly classified as members of the genus Gomphus. Both species were reclassified recently as Phanogomphus. In the world of taxonomic classification, there are “lumpers” and “splitters.” Score one for the splitters!

Notice the first photo shows the wings folded above the abdomen. I spotted the teneral dragonfly when it flew toward me from the pond shoreline. The dragonfly rested in this location for a few minutes before it flew to a new spot (shown below) where it perched briefly with its wings unfolded. The last time I saw the dragonfly, it was flying toward the forest alongside the pond.

The other teneral dragonfly that I saw — “the one that got away” — was perched on the lawn near the walking path around the lake; it flew toward the forest when I moved closer to take some photographs.

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

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

This specimen is a female, as indicated by her rounded hind wings and terminal appendages.

All female dragonflies have two cerci (superior appendages); in contrast all male dragonflies have two cerci and one epiproct (inferior appendage), collectively called “claspers.” Contrast the appearance of the terminal appendages of this female Ashy Clubtail with a male of the same species.

The last photo in the set is a wider view that shows how well-camouflaged the dragonfly was perched on the lawn around the pond.

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

The Backstory

I was surprised to discover a Lancet Clubtail dragonfly near Mulligan Pond during late-June 2016. Knowing that Ashy Clubtails can be found in the same habitats preferred by Lancet Clubtails, I decided to look for Ashy Clubtails at Jackson Miles Abbott Wetland Refuge beginning in mid-April 2017. Apparently Mulligan Pond is a good place for both species, because I spotted two Ashy Clubtails the first time I went looking for them. Ah, if only odonate hunting were always so easy!

Copyright © 2017 Walter Sanford. All rights reserved.

Late-stage emergent baskettail dragonfly

April 18, 2017

Common Baskettail dragonfly (Epitheca cynosura) was spotted at Painted Turtle Pond during a photowalk around Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA. This individual is a late-stage emergent teneral female.

I photographed the process of emergence from the first sighting to the time when the teneral dragonfly flew away: I shot 23 photos in approximately 16 minutes; time is compressed by showcasing six (6) select photos taken at major milestones during the event.

The following photo is the first image from a time-series documenting the emergence of the teneral female. Elapsed time is expressed in hh:mm:ss format, e.g., 00:00:00 is the time when I spotted the emergent teneral female, and 00:16:08 is the total elapsed time.

13 APR 2016 | 11:38:41 am EDT | Elapsed time: 00:00:00

Notice the drop of fluid at the tip of the abdomen. Emerging dragonflies pump fluid into their wings, causing the wings to expand. Next, the same fluid is withdrawn from the wings and used to expand the abdomen. Excess fluid is expelled afterward.

13 APR 2016 | 11:40:48 am EDT | Elapsed time: 00:02:07

The next photo shows the first time the wings opened.

13 APR 2016 | 11:48:55 am EDT | Elapsed time: 00:10:14

Then the wings closed again and remained closed for a while.

13 APR 2016 | 11:51:02 am EDT | Elapsed time: 00:12:21

The wings reopened a few minutes later. Notice that several wings are malformed slightly.

13 APR 2016 | 11:54:14 am EDT | Elapsed time: 00:15:33

Finally, the wings open up, and very soon the teneral adult flies away. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 468). Princeton University Press. Kindle Edition.

The teneral female dragonfly flew away immediately after the last photo in the time-series.

13 APR 2016 | 11:54:46 am EDT | Elapsed time: 00:16:08

This individual is a female, as indicated by her cerci (superior appendages) and thick abdomen. Common Baskettail females have shorter cerci and a thicker abdomen than males of the same species.

Exuviae (in situ)

Several dragonfly exuviae were spotted at Painted Turtle Pond; it’s possible they are cast skins from Common Baskettail. More later after the exuviae are identified using a dichotomous key for dragonfly larvae.

13 APR 2017 | OBNWR | Common Baskettail (exuvia)

These exuviae are not the one from which the teneral female featured in this post emerged.

13 APR 2017 | OBNWR | Common Baskettail (exuvia)

Copyright © 2017 Walter Sanford. All rights reserved.

Common Baskettail dragonfly (male)

April 16, 2017

A Common Baskettail dragonfly (Epitheca cynosura) was spotted near Painted Turtle Pond during a photowalk at Occoquan Bay National Wildlife Refuge (OBNWR). Common Baskettail is a member of Family Corduliidae (Emeralds); this species is seen during early spring in mid-Atlantic United States like Virginia.

I thought this might be a Slender Baskettail dragonfly (Epitheca costalis) due to narrowing of its abdomen. Turns out that was wishful thinking.

13 APR 2017 | OBNWR | Common Baskettail (male)

This individual is a male, as indicated by his terminal appendages. The curved shape of the cerci (superior appendages) is a key field marker for Common Baskettail; in contrast, the cerci for Slender Baskettail tend to be more parallel. Thanks to Mike Boatwright and Paul Guris, members of the Northeast Odonata Facebook group, for reminding me of this pearl of wisdom!

I think baskettail cerci look “rubberized,” like the handles of metal tools made for working with electricity. Whenever I see this distinctive field marker, shown clearly in the following photos, I know the dragonfly is probably a species of baskettail.

13 APR 2017 | OBNWR | Common Baskettail (male)

The last photo shows a dorso-lateral view of the male dragonfly. Notice the epiproct (inferior appendage) is visible clearly in this photo.

13 APR 2017 | OBNWR | Common Baskettail (male)

Also notice the light-colored spots on the hairs covering the body of the dragonfly. The following article by John Abbott suggests the spots may be some type of pollen.

Related Resource: Identification of Male Epitheca (Tetragoneuria) in Texas, by John C. Abbott.

Copyright © 2017 Walter Sanford. All rights reserved.

Stream Cruiser dragonfly (male)

April 14, 2017

Another Stream Cruiser dragonfly (Didymops transversa) was spotted during a photowalk along Beaver Pond Loop Trail at Accotink Bay Wildlife Refuge, Fairfax County, Virginia USA.

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

Stream Cruiser dragonflies typically perch at a 45° angle because of their extremely long legs, especially noticeable in the last photo.

For another perspective on the same male, both literally and figuratively, see Stream Cruiser dragonfly by fellow photoblogger Michael Powell.

Copyright © 2017 Walter Sanford. All rights reserved.

Stream Cruiser dragonfly (female)

April 12, 2017

A Stream Cruiser dragonfly (Didymops transversa) was spotted during a photowalk along Beaver Pond Loop Trail at Accotink Bay Wildlife Refuge, Fairfax County, Virginia USA.

This individual is a female, as indicated by her rounded hind wings and terminal appendages. Look closely at the face and head of the dragonfly. Can you see why “ice cream sandwich face” is my nickname for Stream Cruiser?

The female landed long enough for me to shoot four photos before she flew away — not enough time for me to point her out to Michael Powell, a fellow amateur wildlife photographer and blogger who joined me in search of his first Stream Cruiser. Fortunately, Mike and I were able to photograph a male Stream Cruiser later the same afternoon. Look for photos of the male in my next blog post.

Addendum

I cropped the photo into a square format in order to remove a distracting element. Can you tell what I dislike about the original version? I prefer the square format. Which version do you prefer?

Copyright © 2017 Walter Sanford. All rights reserved.

More focus stacking with CamRanger

April 10, 2017

When I started experimenting with completely automated focus stacking using CamRanger, I couldn’t tell what, if anything, was happening. In fact, I wasn’t sure the process was working as advertised. So I devised a plan to photograph a simple subject (a six-inch ruler in this case) and use “focus peaking” to track what happened. By the way, it’s worth noting that my Canon EOS 5D Mark II DSLR camera doesn’t feature focus peaking, but the CamRanger app does!

During initial testing, I shot several small focus stacks. The following screen capture shows the display on my iPad mini (with retina display) running the CamRanger app; the focal plane of the lens is highlighted by red focus peaking.

Here’s a screen capture from another test, showing the final location of the focal plane (highlighted in red).

I made a movie that demonstrates what happens when CamRanger creates a focus stack. It was fun to watch the focal plane advance along the ruler as CamRanger captured the shots automatically!

The movie begins with a small focus stack using a “Large” step size (the largest increment of three options). When focus stacking is active, notice that most of the screen is covered by a translucent gray layer that prevents the user from changing settings accidentally. I cancelled the focus stack after two shots. Next I changed the step size to “Medium” and started a new stack. Notice that the focal plane of the lens begins where the last focus stack ended. The new step size is noticeably smaller.

Automated focus stacking using CamRanger (2:12)

As shown in the right side bar of the CamRanger app, I set the camera to shoot RAW plus small JPG. Both file types are recorded on the memory card in the camera; thumbnail versions of the JPG files are displayed at the top of the iPad screen. Although I usually shoot RAW only, JPG files can be transferred via WiFi faster than RAW files!

I set the CamRanger app to wait 10 seconds between shots, in order to allow adequate time for the camera to write the image files to the memory card, transfer the JPG thumbnail from the camera to the app, rack the lens to the next focal plane, and for the external flash units to power cycle.

My first finished automated focus stacks

I created a 30-layer focus stack using a medium increment. The following photo shows the JPG version of the first layer.

I used Adobe Photoshop CC 2017 to create a medium-increment focus stack using the small JPGs because they can be processed faster than RAW. The resulting composite image is shown below.

Finally, here’s the resulting composite image of a five-layer focus stack created from large increment/medium JPG photos. In my opinion, the output looks almost as good as the composite image created from five times as many layers.

Lessons Learned

  • Given a choice, run the CamRanger app on the most powerful tablet you own. I use my iPad mini rather than iPad 3 (with retina display). Although the iPad 3 screen is larger than the iPad mini, it features a slower processor. That being said, the iPad 3 is perfectly suitable for using the CamRanger app for other less processor-intensive tasks.
  • Some lenses, such as my Canon EF100mm macro lens, can be set for manual focus and the CamRanger app can still rack focus automatically. It may be necessary to set other lenses for automatic focus in order to work with focus stacking in CamRanger.
  • If possible, use continuous light sources rather than external flash units. I love me some flash triggers, but they’re not 100% reliable. If you’re shooting stills and the flash fails to fire, it’s no big deal — just shoot another shot. Not so when you miss a critical focus layer. I use a combination of two small LED light sources and a Canon Speedlite tethered to the camera by a Vello flash cable; the Canon flash optically triggers a small Nissin i40 external flash (in SD mode) used for backlight.
  • Turn off “sleep mode’ for my Canon 580EX II Speedlite. (C.Fn-01 set for Disabled.)
  • It’s challenging to determine how many layers to shoot for a given focus stack, especially when using smaller step sizes. Don’t sweat it! Simply shoot more layers by starting where the focal plane is at the end of the last focus stack. Repeat as necessary until you capture as many layers as needed.

What’s next?

Going forward, my plan is to experiment with automated focus stacking using subjects that are more complex than the ruler featured in this post. Preliminary testing suggests it could be challenging to create perfect composite images of objects that are more three-dimensional than the ruler.

Sidebar

I used QuickTime to create the embedded movie (shown above) by tethering my iPad mini to a MacBook Air laptop computer and following the excellent directions provided in How To Display your iPad or iPhone on your Mac (9:44), a tutorial video by Terry White, Adobe Evangelist.

Related Resources

Full disclosure: There are hardware/software solutions for wireless tethering and automated focus stacking that are less expensive than CamRanger. Remember, you get what you pay for!

Copyright © 2017 Walter Sanford. All rights reserved.

House Finches

April 8, 2017

Sometime after I moved to a new apartment, I noticed some cute little reddish-brown birds that sing a cheerful song. I used the free Merlin Bird ID App to identify the bird based upon a few simple observations. Turns out my little friends are House Finches (Haemorhous mexicanus).

As time passed and months stretched into years, I realized the birds appeared in the spring, hung around all summer, and disappeared in the fall.

These newly established eastern populations have since become migratory, and now spend winters in the southern parts of the United States. Source Credit: BioKIDS.

05 APR 2017 | The Beacon of Groveton | House Finch (male)

These photos show two of several House Finches spotted recently near the top of the seven-story parking garage at the Beacon of Groveton, Fairfax County, Virginia USA. Both individuals are male, as indicated by their reddish coloration.

05 APR 2017 | The Beacon of Groveton | House Finch (male)

Copyright © 2017 Walter Sanford. All rights reserved.

Common Whitetail (teneral female)

April 6, 2017

After a seemingly endless off-season, I’m pleased to report odonate hunting season has begun in Northern Virginia!

05 APR 2017 | ABWR | Common Whitetail (teneral female)

A Common Whitetail dragonfly (Plathemis lydia) was spotted during a photowalk along Beaver Pond Loop Trail at Accotink Bay Wildlife Refuge (ABWR), Fairfax County, Virginia USA. This individual is a teneral female, as indicated by her terminal appendages and the tenuous appearance of her wings.

Copyright © 2017 Walter Sanford. All rights reserved.

Autumn Meadowhawk (mature female)

April 4, 2017

25 OCT 2016 | OBNWR | Autumn Meadowhawk (mature female)

The preceding photograph shows an Autumn Meadowhawk dragonfly (Sympetrum vicinum) perching on fall foliage at Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA. This individual is a mature female, as indicated by her terminal appendages, coloration, and tattered wings.

Copyright © 2017 Walter Sanford. All rights reserved.


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