Depth of field

Once a teacher, always a teacher. I guess that’s the reason I like to create and share blog posts that relate to things I’ve learned about photography. Such as depth of field.

Depth of field, more specifically shallow depth of field, is the reason many macro photographers like to do focus bracketing and focus stacking.

In order to demonstrate shallow depth of field, I arranged the same three studio “models” (used in my last blog post) in a way that would be impossible for the camera to capture all three subjects in focus. For what it’s worth, the distance between the closest and farthest model was approximately six inches.

To add to the challenge, I changed the aperture from f/7.1 to f/5.6 — that’s closer to the “sweet spot” of f/4 for the lens in my Panasonic Lumix DMC-FZ300, but the depth of field at f/5.6 is shallower than f/7.1. How shallow is it? (Queue Johnny Carson.) For the answer, I turned to my favorite online “Depth of Field Calculator.”

Notice I selected “Panasonic Lumix DMC-FZ150” as the camera. That’s because the FZ300 isn’t on the long list of cameras supported by the calculator. No problem. I own both the FZ150 and FZ300 and I can tell you they are virtually identical in every significant way.

My camera was mounted on a tripod so that the front of the lens was approximately five inches from the closest subject. The focal length (mm) of the lens was derived from the EXIF info for one of the three photos shown below.

Depth of Field Calculator

Look at the calculator output, highlighted by the red rectangle in the preceding screen capture. Notice the total depth of field is 0.24 inches — that’s only around 1/4 inch! There’s NO WAY all three subjects can be acceptably in focus using my FZ300 and the camera settings I selected.

Post Focus

I used Panasonic “Post Focus” to capture the scene. This time, I used “Post Focus” to select different focus points after the shot was taken. During playback, I selected three focus points, one at a time, and saved the following JPG files.

For the first photo, I selected a focus point on the toy monkey. Notice the orange dinosaur in the background is clearly out of focus. Wait, did I really just say that? Yeah, go with it — you know what I mean.

Focus point on nearest subject.

For the next photo, I selected a focus point on the green dinosaur. I don’t know whether I’d call the other two subjects “acceptably in focus” but I know they aren’t tack sharp.

Focus point on middle subject.

For the last photo, I selected a focus point on the orange dinosaur. Notice the toy monkey in the foreground is out of focus.

Focus point on farthest subject.

So there it is — if you would like all three subjects to be in focus then focus bracketing / focus stacking is the only way to go.

My last blog post, entitled “Focus bracketing using Panasonic “Post Focus,” explains how Panasonic “Post Focus” can be used with Adobe Photoshop to do focus bracketing and focus stacking.

Related Resources

• How to use the Post Focus / Focus Stacking feature. [An article from Panasonic.]
• Experience 4K Post Focus in Panasonic LUMIX Cameras – Presented by LUMIX Luminary Photo Joseph, by Panasonic North America (4:33)
• Panasonic FZ80/82 Digital Zoom, 4K Post Focus and Manual Focus, by Graham Houghton (15:16) [The segment related to “Post Focus” begins at ~8:22.]

Copyright © 2022 Walter Sanford. All rights reserved.

Panasonic Image App

The Panasonic Image App enables wireless tethering of select Panasonic digital cameras with smart phones and tablets. The free app is available for both Apple iOS and Android devices.

The app works well when it’s used in a way that’s as simple and straightforward as possible — try to make all or almost all camera settings before starting the Wi-Fi connection (such as P, A, S, M), and limit the number of settings changes made using the app. Otherwise, there seems to be a risk of losing the Wi-Fi connection, although if that happens, it’s easy to reestablish the connection. Hey, there’s a reason many professional photographers prefer using a cable for tethering!

You can control the camera directly while using the app, but I don’t recommend it. In my limited experience using the app, I noticed this can result in the unexpected loss of the Wi-Fi connection.

Home

I highly recommend following Graham Houghton’s excellent directions for connecting the camera and iOS device. Regular readers of my blog might remember I reprogrammed the Fn2 button on my FZ300, so the way I start Wi-Fi is different than the procedure Graham describes in his YouTube video.

After a Wi-Fi connection is established between my Panasonic Lumix DMC-FZ300 superzoom bridge camera and my Apple iPad mini 6, the “Home” screen appears in “Panasonic Image App.” Tap the “Remote operation” button.

Live Control

The following annotated screen capture shows the “Live Control” panel. The function of all of the buttons in the panel is labeled in red text except for ISO, but we know what that means, right?

The live view window (left side of panel) shows the camera settings across the top and bottom of the window. Tap the “DISP.” to toggle this information on/off.

Top, from left-to-right: Program mode; Standard photo style plus modifications; no flash; video settings; settings for picture size and quality; AFS (focus mode, single point); and AF Macro mode as indicated by the AF-flower(icon).

Bottom, from left-to-right: Metering Mode (single point); aperture f/2.8; shutter speed 2.5″; exposure meter; and White Balance (flash).

Tap the Program Shift button (P/double-headed arrow icon) in order to change settings in Program Mode. The icon that appears for this button varies depending upon the camera mode. For example, the icon changes to “F/SS” when the camera is set for Manual Mode, as shown in the next screen capture.

The following image shows the camera set for Custom setting C1 in Manual Mode.

Tap the “F/SS” button (shown above) and a menu appears to set the aperture (F) and shutter speed (SS), as shown below. Press the go-back icon to return to the “Live Control” panel.

Notice the up/down buttons for MF (Manual Focus) on the “Live Control” panel. I need to explore this feature further. I’m hoping this implementation of Manual Focus is better than the one featured on the FZ300. In my opinion, the implementation of Manual Focus on the FZ150 is far superior to the FZ300. Hey Panasonic, are you listening?

Press the “Q.MENU” button in the “Live Control” panel in order to see the “Recording Settings” panel.

“Jump Snap” — one of the most mysterious buttons on the “Live Control” panel — is explained in the section entitled “Taking pictures mid-jump” on the following Web page: Image App (iOS) – Digital Camera.

Playback

Tap the “Play back” button, located along the bottom of the screen, in order see all of the photos and videos saved to the camera memory card.

Tap the “Menu” button, located along the bottom of the screen, in order to access “Playback settings.”

“Live Control Settings” and “Help” (shown above) might be worth a look as well, although I don’t recall exploring those Menu items.

Related Resources

• Demonstrating the Panasonic Image App on an IOS device, by Graham Houghton (23:05). See also “Demonstrating the Panasonic Image App on an Android device,” by Graham Houghton (19:38).
• Panasonic Basic Operating Instructions, Digital Camera, Model No. DMC-FZ300. See the section entitled “Wi-Fi,” pp. 41-45.
• Remote control recording [tap the “Live Control” button, located along the bottom of the screen]
• Image App (iOS) – Digital Camera [This page includes a warning for app users: “Since Wi-Fi connection drains battery quickly it is better to recharge before use when power is low.” I recommend using either an internal or external continuous power source for the FZ300.]
• Adding location information from smartphone onto digital camera images (Geotagging) [see “Home” screen]
• Join Snap Movies [see “Home” screen]
• Editing still pictures on Photo Collage function [see “Home” screen]
• Saving digital camera images on smartphone, sending them to websites, sharing them with other devices
• Playing back images on digital camera
• About menu screen [tap the “Menu” button, located along the bottom of the screen]

Copyright © 2022 Walter Sanford. All rights reserved.

Arrowhead Spiketail (terminal appendages)

Arrowhead Spiketail dragonflies (Cordulegaster obliqua) were spotted along small streams at undisclosed locations in Fairfax County and Prince William County, Virginia USA.

Male and female Arrowhead Spiketails are similar in appearance. They can be differentiated based upon several field marks.

Male

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

07 JUL 2014 | Fairfax County | Arrowhead Spiketail (male)

Arrowhead male and female cerci are similar in appearance, and it can be challenging to see the epiproct clearly from some viewpoints. When in doubt whether an individual is male or female, look for indentations at the base of the hind wings of males.

07 JUL 2014 | Fairfax County | Arrowhead Spiketail (male)

Female

This individual is a female, as indicated by her rounded hind wings, terminal appendages, and prominent subgenital plate (ovipositor) at the tip of her abdomen.

21 MAY 2019 | PNC. Wm. County | Arrowhead Spiketail (female)

Although Arrowhead male and female cerci are similar in appearance, there is no mistaking the subgenital plate of female spiketails! It’s easy to see why “Spiketails” is the common name for Family Cordulegastridae.

21 MAY 2019 | PNC. Wm. County | Arrowhead Spiketail (female)

So the take-away is simple: If you see a subgenital plate then the individual is definitely female; if not, then it’s probably a male.

Copyright © 2022 Walter Sanford. All rights reserved.

Mind blown!

I don’t know exactly what eBay is today, but I know it was a Den of Thieves where people could go to buy and sell stuff, usually used. And I know several people who were ripped off (lost money) on eBay, both as buyers and sellers. As a result, my mindset toward eBay has been “avoid it like the plague!”

eBay seems to have evolved into an Amazon-like online superstore where you can shop for new stuff as well as buy/sell used stuff. Imagine my surprise when I rolled the dice and ordered a hard-to-find item from a vendor in Japan and the experience turned out to be 99.9% positive. Mind blown!

The Backstory

A long time ago, I bought a “tele conversion lens” and adapter for my Panasonic Lumix DMC-FZ150 superzoom bridge camera. Both accessories were made by Panasonic. Using the tele conversion lens, the actual magnification is 1.7 times the display. For example, at 24x — the maximum zoom magnification of the FZ150 — the actual magnification is ~40x!

When I upgraded to the Panasonic Lumix DMC-FZ300, I wanted to be able to use the same “tele conversion lens.” It was unclear to me whether the DMW-LA5 adapter that works with the FZ150 would fit my FZ300. I was aware that Panasonic also made (past tense) a DMW-LA7 adapter for the Panasonic Lumix DMC-FZ200, but I wasn’t sure the same adapter/lens combo would work with my FZ300.

Impasse Breakthrough

Recently I stumbled across a comment by a Panasonic employee in the Q&A section of an archived product page for the DMW-LA7 adapter (regret I can’t remember where I read the comment) in which the employee clearly stated the adapter is compatible with the FZ300.

Product image courtesy Panasonic Store on Amazon.

Turns out the adapter is no longer made by Panasonic so I started searching online for a place to buy the adapter, new or used. After a lot of fruitless searching, I found several vendors on eBay that sell the adapter. I fully expected the adapter would turn out to be a knock-off of some sort, but hey, it’s essentially just a metal tube with screw threads on both ends so I figured any DMW-LA7 compatible adapter should work. I decided to place an order with a company called “Japan-Excite.”

My order was delivered 10 days later. I was STUNNED when I opened the “parcel” and discovered the adapter is original equipment from Panasonic, in the original box, and apparently new! And I was delighted that it fits perfectly on my FZ300 and with the DMW-LT55 tele conversion lens.

Needs Improvement

So why did I say the experience was 99.9% positive? Because the “parcel” used to ship the product looked like a laminated paper bag of some sort — it reminded me of the brown paper bag lunches my mother used to pack when I was in elementary school. Inside the bag, the item was packed in bubble wrap enclosed by corrugated cardboard folded four times to fit around the bubble wrap (open on both ends). All of that said, the product was delivered in good condition. But I must say that I would NEVER ship merchandise from Japan to the United States (or vice versa) using anything less than a sealed cardboard box with plenty of packing material surrounding all sides of the product.

Summary

Long story short, all’s well that ends well although I can’t help but feel like I was extraordinarily lucky!

In summary, the Panasonic DMW-LT55 tele conversion lens works with either the DMW-LA5 or DMW-LA7 adapter: the DMW-LA5 adapter works with the Panasonic Lumix DMC-FZ150; the DMW-LA7 adapter works with both the Panasonic Lumix DMC-FZ200 and Panasonic Lumix DMC-FZ300.

I’m eager to field test the new adapter with my FZ300 to see whether the tele conversion lens performs as well as it does using my FZ150.

Related Resources

• Sailboats – a blog post by Walter Sanford.
• Panasonic Lens Adaptor DMW-LA7 dmwla7 DMC-FZ200 – sold by Japan-Excite.
• Panasonic digital camera optional lens adapter DMW-LA7 – sold by a vendor on Amazon. After a little poking around on the Amazon Web site I concluded this item probably IS NOT sold directly by Panasonic, rather it is sold by a store front for one of several third-party vendors.

Copyright © 2021 Walter Sanford. All rights reserved.

Follow-up: Raynox DCR-250 close-up filter

In my last blog post, I mentioned that minor vignetting can be a problem when the Raynox DCR-250 close-up filter is mounted on some macro- and non-macro camera lenses.

Canon 100mm macro lens

In case you’re wondering whether vignetting is a problem when using two step-down rings with the Canon 100mm macro lens, it isn’t. As it turns out, the front lens element is recessed quite a bit from the lens barrel so the step-down rings cover little if any glass. Source Credit: Raynox DCR-250 close-up filter, by Walter Sanford.

The first photo shows the front lens element of the Canon 100mm macro lens is in fact recessed quite a bit from the lens barrel.

Lens barrel without nested step-down rings.

The next photo shows the nested 67-52mm and 52-43mm step-down rings that I use to mount the Raynox DCR-250 on my Canon 100mm macro lens. Look closely at the full-size version of this image and you should see the step-down rings don’t cover any of the camera lens.

Lens barrel with nested step-down rings.

Disclaimer: This might or might not be true for other makes and models of 100mm macro lenses.

Panasonic Lumix superzoom bridge cameras

The camera lens will need to be adjusted for at least some slight telephoto zoom in order to eliminate the vignetting caused by mounting a 43mm filter on a lens with a 52mm filter size. Source Credit: Raynox DCR-250 close-up filter, by Walter Sanford.

A Guide To Using Raynox Close Up Lenses on the FZ200 Camera, by Graham Houghton is the second item listed under “Related Resources” in my last blog post. Page 6 of Graham’s excellent guide describes a simple way to set-up both my Panasonic Lumix DCR-150 and DCR-300 superzoom bridge cameras so that vignetting isn’t a problem.

p. 6, A Guide To Using Raynox Close Up Lenses on the FZ200 Camera, by Graham Houghton.

For the DMC-FZ300, press the “Menu/Set” button on the back of the camera, then select the camera icon in the left side-bar. Navigate to page 7/7 and select “Conversion”; select the icon for close-up lens. When the camera is powered-on, it will zoom to 4x (121 mm) automatically and the aperture will be limited to f/4 or smaller (f/4 to f/8).

For my older DMC-FZ150, the set-up process is the same except “Conversion” appears on page 5/5. Zoom is set to 4x and the aperture is limited to f/3.6 or smaller (f/3.6 to f/8).

Using either camera, the lens can be adjusted for greater than 4x zoom, resulting in more magnification.

Post Update

You know, sometimes I wonder “What was I thinking?”

Although I like Graham Houghton’s trick for using one of the “Conversion” settings to quickly solve the vignetting problem on the Panasonic superzoom bridge cameras, I dislike the fact that aperture is limited by that setting. That’s a bad trade-off, in my strong opinion.

Another strike against using the “Conversion” setting: flash is disabled, including both the built-in flash and the flash hot-shoe. I like to use flash for macro photography, so this is a deal-breaker for me.

Copyright © 2021 Walter Sanford. All rights reserved.

Raynox DCR-250 close-up filter

I watched a video by Micael Widell recently that reminded me the Raynox DCR-250 close-up filter is a good value given its versatility.

Before I bought the Raynox close-up filter many years ago, I was skeptical that it would work. I still can’t explain why it works with many lenses I own including both macro- and non-macro lenses, but I can tell you with certainty it does work and works well!

Canon 100mm macro lens

The Canon 100mm macro lens has a maximum magnification of 1:1. Micael Widell says adding the Raynox DCR-250 close-up filter to the lens increases the magnification from 1x to 2x. According the B&H Photo Specs page for the Raynox DCR-250 close-up filter, its magification is 2.5x.

Calculating magnification is tricky and not as straightforward as one might think. In this case it doesn’t matter whether Mr. Widell or B&H Photo is correct, the fact of the matter is adding a Raynox DCR-250 close-up filter to your lens should at least double the magnification.

The first photograph shows the following equipment, couterclockwise from the upper-left: “snap-on universal adapter” for Raynox DCR-250 close-up filter; Raynox close-up filter mounted on a 52-43mm step-down ring; and a 67-52mm step-down ring.

Several mounting adapters for Raynox DCR-250 close-up filter.

The Raynox DCR-250 close-up filter comes with a “snap-on universal adapter” for mounting the filter on lenses with a filter size from 52-67mm. The universal adapter clips on the front of a lens the same as a lens cap. That’s OK for use in a photo studio but less than ideal for use in the field. In my opinion, it’s better to use inexpensive step-down rings to mount the close-up filter more securely.

Canon EOS 5D Mark II macro photography kit.

The Rube Goldberg rig shown above has a lot of parts, but for the purpose of this blog post focus on the Canon 100mm macro lens and Raynox DCR-250 mounted on the lens using nested 67-52mm and 52-43mm step-down rings.

In case you’re wondering whether vignetting is a problem when using two step-down rings with the Canon 100mm macro lens, it isn’t. As it turns out, the front lens element is recessed quite a bit from the lens barrel so the step-down rings cover little if any glass.

Panasonic Lumix superzoom bridge cameras

Both my Panasonic Lumix DCR-150 and DCR-300 superzoom bridge cameras feature a 52mm filter thread size. So it’s simple to use a 52-43mm step-down ring to mount the Raynox DCR-250 close-up filter on either camera lens.

Raynox DCR-250 not mounted on the camera lens.

The camera lens will need to be adjusted for at least some slight telephoto zoom in order to eliminate the vignetting caused by mounting a 43mm filter on a lens with a 52mm filter size.

Both cameras feature a 24x zoom lens, so when the Raynox DCR-250 is added to the kit the actual magnification will vary depending upon the focal length for which the camera lens is set.

Raynox DCR-250 shown mounted on the camera lens.

Related Resources

• 3 Ways to Increase Your Macro Lens Magnification from 1x to 2x! by Micael Widell (7:15). (00:54) 1. Raynox filter. (02:22) 2. Extension tubes. (05:13) 3. teleconverter (called an “extender” by Canon).
• A Guide To Using Raynox Close Up Lenses on the FZ200 Camera by Graham Houghton – “A fairly comprehensive look at the selection and use of the Raynox macro lenses [close-up filters] that are available for achieving close up images with the FZ200 camera.”
• RaynoxAdapterCalculator – another good resource from the Extreme Macro Web site.
• Sensor Size and Magnification – correcting a common misunderstanding, by Allan Walls Photography (20:02). The video segment from 5:48 to 14:33 is money, especially the discussion related to the “Thin Lens Formula” beginning around 11:24.
• Sensor Size Matters – Part 1 (the Front Half) – A Demonstration, by Allan Walls Photography (19:51). This demonstration is follow-up for the preceding video.

Copyright © 2021 Walter Sanford. All rights reserved.

Yellow-sided Skimmer (female, male)

Thanks to a tip from fellow odonate enthusiast Michael Ready, I was able to add another species of dragonfly to my life list recently: Yellow-sided Skimmer dragonfly (Libellula flavida).

Female

The first Yellow-sided Skimmer dragonfly that I spotted was perched along the shoreline of a small pond at an undisclosed location in Prince William County, Virginia USA. This individual is a female, as indicated by her terminal appendages.

Female Yellow-sided Skimmers have a pair of flanges beneath their eighth abdominal segment that are used to scoop and hold a few drops of water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

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

I followed the female from one perch to another, “working the shot.” The next two photos are full-frame (4,000 x 3,000 pixels), that is, uncropped.

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

Notice the amber color near the leading edge of her wings, a good field mark for L. flavida.

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

Male

According to Dr. Steve Roble’s excellent datasets for the Commonwealth of Virginia, the adult flight period for Yellow-sided Skimmer is from May 15 to September 21.

By mid-June most males, including this one, are completely covered by light-blue pruinescence that obscures the yellow coloration on the sides of their thorax. Look closely at the full-size version of the following photo and you should see the amber color near the leading edge of his wings.

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

Habitat

A small, seep-fed pond located in the forest provides ideal habitat for Yellow-sided Skimmer.

Habitat: Boggy ponds, seeps, slow streams, and weedy ditches. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Location 9094). Princeton University Press. Kindle Edition.

23 MAY 2018 | PNC. Wm. County | small, seep-fed pond

Notice the fallen tree that lies between the foreground and the pond in the background, nearly perpendicular to the stream. The tree is a barrier that slows the flow of the stream, creating the type of boggy, weedy habitat that Yellow-sided Skimmer prefers.

Range maps

Not all species of Skimmers are as common as I tend to think. For example, the following map shows all official records for Libellula flavida in the United States of America. As you can see, Yellow-sided Skimmer is a relatively uncommon species of odonate.

Zooming in to reveal the details shows few records reported for Northern Virginia, where I live.

What are the take-aways?

Many species of dragonflies in the Family Libellulidae (Skimmers) are habitat generalists and relatively easy to find almost anywhere there is water. In contrast, I think it’s fair to say Yellow-sided Skimmer is a habitat specialist that is challenging to find.

Related Resource: Libellula flavida Yellow-sided Skimmer on NatureServe Explorer. The conservation status for L. flavida in Virginia is “Vulnerable (S3).”

Copyright © 2021 Walter Sanford. All rights reserved.

It’s all about habitat, habitat, habitat.

Seeps and small streams in the forest are perfect places to look for habitat specialist dragonflies such as petaltails and spiketails.

An old place revisited.

The following photograph of a forest seep has been featured in my blog at least once in the past. The seep feeds a small pond; Gray Petaltail dragonflies (Tachopteryx thoreyi) can be found feeding and perching in sunny spots around the pond during late-May and early-June.

23 MAY 2018 | Prince William County, VA | forested seep

The seep is the habitat where Gray Petaltail larvae live most of their lives, not the pond. I always wondered how so many adult petaltails could emerge from this relatively small seep.

Turns out Michael Powell, my good friend and photowalking buddy, must have been wondering the same thing because he explored the area upstream from the small seep shown above and discovered several more seeps located close to the one near the pond.

The next photo shows Mike resting on a log along the edge of one of the seeps, near the confluence of two small streams. Notice the patch of skunk cabbage (Symplocarpus foetidus) growing in the seep — a good sign that you might be looking at habitat suitable for Gray Petaltail.

13 APR 2021 | Prince William County, VA | forested seep

A new place worth exploring further.

Mike also discovered another small stream in the forest when he was exploring for Uhler’s Sundragon (Helocordulia uhleri). The stream is located at the approximate midpoint between two trails, so I nicknamed it “Middle Creek.” Clever, huh? Note the patch of skunk cabbage growing in a seep alongside the stream. Did an alarm just go off in your head?

13 APR 2021 | Prince William County, VA | forested stream and seep

Mike and I are eager to explore the stream further, mainly looking for Gray Petaltail during late spring. Several species of spiketails might be found there as well.

Copyright © 2021 Walter Sanford. All rights reserved.

Cobra Clubtail versus Midland Clubtail

Odonate exuviae from two species in Genus Gomphurus — Cobra Clubtail (Gomphurus vastus) and Midland Clubtail (Gomphurus fraternus) — are nearly perfect body doubles, with the exception of one key field mark that can be used to differentiate the species.

Dorsal views

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

Lateral spines are located on abdominal segments six through nine (S6-S9) for both species.

10 JUN 2019 | Barron County, WI | Midland Clubtail exuvia (dorsal)

Ventral views

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

The overall shape of the prementum is similar for both species.

10 JUN 2019 | Barron County, WI | Midland Clubtail exuvia (ventral)

Prementum (ventral view)

The shape of the palpal lobes on the prementum is different for the two species, as shown in the following diagram on p. 15, Key to the species of genus Gomphurus, Identification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz.

Identification Keys to Northeastern Anisoptera Larvae

The following images are magnified approximately three and one-half times life size (~3.5x).

27 MAY 2017 | Riverbend Park | Gomphurus vastus (exuvia)

For both species, focus on the row of teeth along the right palpal lobe. Notice the strongly curved shape of the palpal lobe for Cobra Clubtail (shown above), in contrast with the gently arched shape of the palpal lobe for Midland Clubtail (shown below). Also notice the Cobra palpal lobe has fewer teeth than Midland.

10 JUN 2019 | Barron County, WI | Gomphurus fraternus (exuvia)

Adults

Adult Cobra Clubtail dragonflies are almost identical to Midland Clubtails too. Several field marks can be used to differentiate the two species. In my opinion, one field mark is the easiest to recognize where it really matters — in the field!

16 MAY 2016 | Riverbend Park | Cobra Clubtail (adult male)

Notice there aren’t any mid-dorsal marks on abdominal segments eight and nine (S8-S9) for Cobra Clubtail (shown above). In contrast, there is a small yellow triangle on abdominal segment eight (S8) for Midland Clubtail (shown below). This is true for males and females of both species.

Photo used with permission from Freda van den Broek.

Copyright © 2020 Walter Sanford. All rights reserved.

Cross-compatibility of Godox TT685-series flashes

The following quick-and-dirty video is a demonstration of the cross-compatibily among Godox TT685-series external flash units, including a Godox TT685F, TT685o/p, and TT685C (shown from left-to-right). All three flash units were test-fired using Godox X2TF and X2To/p radio flash triggers.

Notice the brand of flash trigger used to fire the flashes appears in the lower-left corner of the LCD on each flash. The beginning of the video shows all three flash units had been fired by a Godox X2TF (for Fujifilm) set for TTL mode. Think about that — now the TT685o/p (center) and TT685C (right) “think” and operate like the Fujifilm-compatible flash (left). Incredible!

Next I switched to a Godox X2To/p (for Olympus and Panasonic), changed the mode to Manual (M), and test-fired the flashes.

Take-aways

The cross-compability of Godox TT685-series flashes makes these relatively inexpensive, well-made flashes an even better value. By buying wisely it’s possible to assemble an array of flashes that provides maximum flexibility. Bravo, Godox!

Editor’s Commentary

You know, I actually had a vision of how I wanted this video to turn out before I started shooting. Let’s just say my vision wasn’t realized. I like to think I’m a fairly good photographer; videographer, not so much. Perhaps I’ll re-do the video when I’m not as pressed for time as I was for this iteration.

Copyright © 2019 Walter Sanford. All rights reserved.