Archive for the ‘Fujifilm X-T1’ Category

Test shots: Pachydiplax longipennis exuvia

November 19, 2018

A Blue Dasher (Pachydiplax longipennis) exuvia was received from Andy Davidson, a graduate student at Virginia Commonwealth University.

Test shots of the specimen were taken using a relatively small aperture of f/20 for greater depth of field. Each photo is a “one-off,” that is, not a composite image. Focus stacks will be created sometime in the near future, after the exuvia is rehydrated and posed for better composition.

Extremely shallow depth-of-field is a common problem in macro photography. Depth-of-field increases as aperture decreases — in other words, they are inversely related. In this case, an aperture of f/20 was insufficient for the entire subject to be acceptably in focus so it will be necessary to create some focus stacks.

Also notice the background of the second photo looks darker and bluer than the first one. That was caused by the fact that the subject was farther from the front of the lens. There are work-arounds for this lighting problem, but hey, like the title of this blog post says these are “test shots.”

Related Resources

Tech Tips

The following equipment was used to shoot both of the macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. 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. For details, see “More Tech Tips” (below).

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control a pair of off-camera Godox TT685 Thinklite TTL Flashes(TT685F and TT685C) set for radio slave mode. Each flash was fitted with a snap-on plastic diffuser.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen both images.

Copyright © 2018 Walter Sanford. All rights reserved.

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Test shots: Erythemis simplicicollis exuvia

November 16, 2018

An Eastern Pondhawk (Erythemis simplicicollis) exuvia was received from Andy Davidson, a graduate student at Virginia Commonwealth University.

This individual is a male, as indicated by the vestigial hamules visible on the ventral side of the exuvia, abdominal segments two and three (S2-S3).

Food for Thought

This exuvia is one of three “cast skins” from odonate nymphs that were collected in the field and reared in the laboratory as part of a research project entitled “Predator-Prey Interactions in a Changing World.” Since all three nymphs were collected from the James River rock pools, I assume they lived in essentially the same habitat. I wonder why the E. simplicollis exuvia is so much darker in color than either the P. flavescens or P. longipennis exuviae.

Related Resources

Tech Tips

The following equipment was used to shoot both of the macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. 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. For details, see “More Tech Tips” (below).

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control a pair of off-camera Godox TT685 Thinklite TTL Flashes(TT685F and TT685C) set for radio slave mode. Each flash was fitted with a snap-on plastic diffuser.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen both images.

Copyright © 2018 Walter Sanford. All rights reserved.

Test shots: Pantala flavescens exuvia

November 14, 2018

A Wandering Glider (Pantala flavescens) odonate exuvia was received from Andy Davidson, a graduate student at Virginia Commonwealth University in Richmond, Virginia USA. Sincere thanks to Andy for sharing this beautiful specimen!

The exuvia is a “cast skin” from a nymph that was collected in the field and reared in the laboratory as part of a research project entitled “Predator-Prey Interactions in a Changing World.”

Test shots of the specimen were taken using a relatively small aperture of f/16 for greater depth of field. Each photo is a “one-off,” that is, not a composite image. Focus stacks will be created sometime in the near future, after the exuvia is rehydrated and posed for better composition.

Related Resources

Tech Tips

The following equipment was used to shoot both of the macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. 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. For details, see “More Tech Tips” (below).

Godox XProF radio flash trigger, mounted on the hotshoe of my X-T1, was used to control a pair of off-camera Godox TT685 Thinklite TTL Flashes (TT685F and TT685C) set for radio slave mode. Each flash was fitted with a snap-on plastic diffuser.

Adobe Photoshop CC 2017 was used to spot-heal and sharpen both images.

More Tech Tips

Focus peaking can be activated when the camera is set for manual focus mode. Using back-button focus (AF-L button) in manual mode enables one to retain full control of the exposure triangle, focus quickly, and see what’s in focus before shooting a photograph. Fuji Back Button Focus (4:06), a YouTube video by Ashraf Jandali, provides a clear demonstration of how to use back-button focus on the Fujifilm X-T1.

Copyright © 2018 Walter Sanford. All rights reserved.

Godox TT685C Thinklite TTL Flash

November 12, 2018

I bought a Godox TT685C Thinklite TTL Flash from Roberts Camera recently. I placed the order around midday on Friday, 02 November 2018 and the parcel was delivered on Monday, 05 November. Impressive!

The Backstory

Godox flash photography gear, published on 09 October 2019, features my initial review of a Godox TT685F Thinklite TTL Flash that I bought from B&H Photo. In short, the flash doesn’t work as advertised by both Godox and B&H Photo, and B&H has failed repeatedly to “make it right.” (More about that in a follow-up blog post.)

Given my negative experience with the TT685F flash, regular readers of my blog might be wondering “Why would you buy another Godox flash from B&H Photo?” More about the first part of that question in a minute. As I already mentioned, I DIDN’T buy the new Godox TT685C flash from B&H Photo. Read between the lines.

Testing 1, 2, 3…

I have been testing the new TT685C flash since the day after it was received. Here’s what I know so far: In a nutshell, the flash works as advertised.

The Canon-compatible version of the Godox TT685 functions in five modes: a non-wireless, stand-alone mode (TTL, Manual, and Multi); and four wireless modes (optical master/slave modes, and radio master/slave modes). The Godox TT685C can do almost everything the comparable Canon Speedlite 600EX II-RT does at a price point approximately six times less than Canon’s MSRP of $579.99.

All of that being said, there is one problem with the Godox TT685C and it’s a big problem in my opinion. More about this in a follow-up blog post.

A Canon-compatible flash that works like one made for Fujifilm

For my money, what makes the Godox TT685 product line of flashes special is they are cross-compatible. In other words, flashes made for different camera manufacturers (e.g., Canon, Nikon, Olympus/Panasonic, and Sony) can work together.

The following photo shows the LCD of my new Godox TT685C flash. The flash is set for radio slave mode (Channel 1, Group A). Notice the word “FUJI” in the lower-left corner of the display that indicates the Canon-compatible flash is working like a Fujifilm-compatible flash.

In this case, the flash was controlled by a Godox XProF radio flash trigger mounted on the hotshoe of my Fujifilm X-T1 digital camera. A Godox TT685F external flash, fitted with a Lastolite Ezybox Speed-Lite 2 flash modifier, was located off-camera; the TT685F was used to light the photo, shown below. Also notice the icon that indicates the flash is functioning in HSS mode; the HSS icon is located below 24mm (manual zoom) and the audio speaker icon (indicating sound is on).

Godox TT685C external flash LCD panel display (Slave mode).

Results from hands-on testing (so far, so good)

  • Off-camera radio slave mode works, including TTL and HSS, when the Godox TT685C is controlled by a Canon MT-26EX-RT Macro Twin Lite set for radio master.
  • Either Godox XProF or TT685F mounted on Fujifilm X-T1 hotshoe: Camera-mounted flash is Channel M; off-camera TT-685C (set for radio slave) is Channel A. Works as expected, including TTL and HSS.
  • Godox TT685C mounted on Fujifilm X-T1 hotshoe: Flash fires, Manual mode only (TTL, HSS don’t work); when the flash is set for optical master (in Manual mode), it can trigger an off-camera Nissan i40 external flash unit (set for SF Mode) confirming that optical master does in fact work.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Consistency and attention to detail

October 14, 2018

Fujifilm doesn’t make/sell any radio-controlled flash triggers and external flash units, so I was excited when I learned that Godox had released Fujifilm-compatible flash photography gear that fills the void. Better, the retail price-point for the Godox gear is quite attractive — about one-fifth the price of comparable Canon external flash equipment.

Buyer beware: You get what you pay for. In the case of the Godox flash gear for Fujifilm, it seems like you’re paying for a work-in-progress rather than a finished, market-ready product.

Fujifilm X-T1

The first two images show two screen captures from the flash-related “Shooting Menu” for the Fujifilm X-T1 digital camera.

Flash-related Shooting Menu for Fujifilm X-T1 digital camera.

Notice camera is set for TTL and high-speed sync is enabled (FP).

Flash-related Shooting Menu for Fujifilm X-T1 digital camera.

Godox TT685F

The following graphic is an outtake from the Instruction Manual for the Godox TT685F external flash unit. The annotated image shows the LCD panel on the front of the flash.

Godox TT685F Thinklite TTL Camera Flash | Instruction Manual

When the Godox TT685F is mounted on the hot shoe of a Fujifilm X-T1 digital camera, the LCD panel looks similar to the annotated image in the instruction manual. Notice the icon that indicates the flash will fire using high-speed sync.

Godox TT685F external flash LCD panel display.

The next graphic is an outtake from the Instruction Manual for the Godox TT685F external flash unit. The annotated image shows the LCD panel on the front of the flash when the flash is set for either Master or Slave mode.

Godox TT685F Thinklite TTL Camera Flash | Instruction Manual

Finally, here’s the LCD panel display for the TT685F in Slave mode. Conspicuously missing is any indication the flash is set for high-speed sync.

Godox TT685F external flash LCD panel display (Slave mode).

Godox XProF

The following image shows the LCD panel for the Godox XProF radio flash trigger. Notice the display is somewhat similar to the TT685F display when set for Master mode.

Godox XProF radio flash trigger LCD panel display.

The next image shows the LCD panel for the XProF radio flash trigger, showing only a single channel and group. Neither view provides any indication the flash will fire using high-speed sync.

Godox XProF radio flash trigger LCD panel display.

Inconsistency seems to be a problem with Godox

It appears there is some inconsistency across the product line of TT685 flashes made for different camera manufacturers (Canon, Nikon, Olympus/Panasonic, and Sony). For example, some models of the TT685, such as the TT685C for Canon cameras, feature both optical and radio master/slave modes; the TT685F for Fujifilm cameras is radio only.

There is also inconsistency and inattention to detail across the LCD panel displays for the XPro controllers for different camera manufacturers. For example, notice that “SYNC” is one of the four function buttons on the XProC (press the button and the flash goes into HSS mode); the “SYNC” button is missing from the XProF, as shown above.

Godox TT685C Thinklite TTL Camera Flash | Instruction Manual

Most, if not all of these issues should be easy to fix by updating the firmware; hopefully updates are in the pipeline already.

And speaking of firmware updates, the firmware for Godox flash photography products can be updated using Windows-compatible PCs only. Really, you’re kidding me, right? Seriously Godox, many if not most “creatives” — including photographers — prefer Apple computers. It’s time to make firmware updates available for either Apple Mac OS or Microsoft Windows!

Post Update: It works, except when it doesn’t.

Further experimentation showed that the XProF LCD display can show the icon that indicates the flash will fire using high-speed sync, as shown below. Here’s how I was able to make it work, albeit temporarily.

  1. Power-on the XProF.
  2. Power-on the X-T1.
  3. Press the “Menu/OK” button and navigate to the “Shooting Menu,” specifically the “Flash Function Setting.” (Both menus are shown at the beginning of this post.) Cycle through the three options in the sub-menu under “Sync” (1st Curtain, 2nd Curtain, FP); select FP. Press the “OK” button.

As far as I can tell, the Sync mode must be set every time you power-on the flash gear and camera, including after the X-T1 goes into power-saving sleep mode. If you don’t, then HSS works but the HSS icon isn’t displayed on the XProF LCD panel.

It’s noteworthy that the HSS icon is never displayed on the TT685F LCD panel when the flash is in Slave mode — more evidence of inattention to detail.

Godox XProF radio flash trigger LCD panel display.

Godox XProF radio flash trigger LCD panel display.

Copyright © 2018 Walter Sanford. All rights reserved.

Burst mode flash photography

October 12, 2018

This post provides a brief demonstration of burst mode flash photography using the gear shown in the following photo: Fujifilm X-T1 digital camera plus Fujifilm MCEX-11 extension tube and Fujinon XF80mm macro lensGodox XProF radio flash triggerGodox TT685F external flashGodox PROPAC PB960 Lithium-Ion Flash Power Pack; and Quantum Instruments CZ2 Power Cable (for Turbo Series Power Packs).

Godox flash photography gear.

The Fujifilm X-T1 digital camera is set for “CL” (continuous low) burst mode. The Godox TT685F external flash unit is set for Manual mode at 1/128 power, as shown on the LCD of the Godox XProF radio flash trigger mounted on the camera hot shoe. The external flash unit is connected to a Godox PROPAC PB960 power pack using a Quantum Instruments cable.

The external flash unit is powered by a set of four AA batteries, as usual. The external power pack enables a much faster recycle rate for the flash than is possible using only AA batteries.

The Quantum Instruments CZ2 Power Cable fits Canon external flash units such as the Canon MT-26EX-RT Macro Twin Lite and Canon 580EX- and Canon 580EX II Speedlites, as well as Godox external flash units made for Canon, Fujifilm, and Olympus/Panasonic digital cameras. You may want to buy two cables, since the Godox PROPAC PB860 can power two flash units at once.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Godox flash photography gear

October 9, 2018

The photos in this gallery show the following photography gear: Fujifilm X-T1 digital camera plus Fujifilm MCEX-11 extension tube and Fujinon XF80mm macro lens; Godox XProF radio flash trigger; Godox TT685F external flash, Godox PROPAC PB960 Lithium-Ion Flash Power Pack; and Quantum Instruments CZ2 Power Cable (for Turbo Series Power Packs).

Godox flash photography gear.

The Godox TT685F flash head is the same size as a Canon 580EX II Speedlite so slide-on plastic light modifiers that work with a 580EX II will work with the TT685. That said, some work better than others. The “Sto-Fen Omni-Bounce OM-EY” is a tight fit — too tight in my opinion. The “Vello Bounce Dome (Diffuser) for Canon 580EX II Flash” is a perfect fit.

The Godox radio flash trigger and external flash unit are compatible with both TTL and HSS (high-speed sync flash).

Godox flash photography gear.

The Godox TT685F external flash can function as either a radio master or radio slave. According to the B&H Photo Web page for the TT685F, current as of 01 November 2018, the flash can also function as either an optical master or optical slave.

Much to my surprise, the TT685F cannot function as either an optical master or optical slave. I had hoped to be able to use the TT685F as an optical master to remotely trigger other Fujifilm-compatible external flash units such as my Nissin i40 or Fujifilm EF-X500. This is a BIG disappointment, especially since the TT685C for Canon Cameras features both optical master/slave and radio master/slave modes. Although both the TT685F and TT685C sell at the same retail price point of ~$110, you’re paying for less-capable hardware in the TT685F and that’s just not right! Hey Godox, are you listening?

The Godox PROPAC PB960 Lithium-Ion Flash Power Pack can be used with the TT685F to enable burst mode flash photography. A follow-up blog post will feature a short video clip showing that burst mode flash works quite well.

Editor’s Notes

I contacted B&H Photo on 10 October 2018 via an online chat with a customer service representative named “Dan W.” Dan admitted the B&H Photo Web page for the Godox TT685F is (or was) incorrect. The following quote is an excerpt from the transcript of my chat with Dan W.

“Optical master/slave transmission is available for working with other standard flashes.”

https://www.bhphotovideo.com/c/product/1348949-REG/godox_tt685f_ttl_camera_speedlite.html

I asked “How do we make this right? I don’t want to return the TT685F but I’d be happy to settle for a discount on another Godox flash.” After talking with a manager, B&H offered to give me a $5.00 discount on another flash unit. B&H misrepresented the product I bought in good faith and their best offer to make it right is $5? Please, get serious.

I have always raved about B&H Photo and its extraordinary customer service. Whenever there has been a problem with an order, it was always resolved quickly in my favor. B&H’s latest offer of a $5.00 discount is an insult and NO WAY TO BUILD CUSTOMER LOYALTY!

Addendum

As it turns out, the Godox Web page for the TT685F, current as of 12 October 2018, says the flash can also function as either an optical master or optical slave.

It’s noteworthy that the graphic of the flash LCD shows the icon for radio master/slave mode. Hey Godox, does anyone fact-check your Web pages before they are published? This is false advertising!

Copyright © 2018 Walter Sanford. All rights reserved.

Post update: Cordulegastridae exuvia

February 16, 2018

In a recent blog post entitled Cordulegastridae exuvia, I was able to identify the specimen to the family level. Since then, I was able to identify the genus and species.

The dichotomous key for Cordulegastridae larvae that appears on p. 330 in Dragonflies of North America, Third Edition by Needham et al. was used to identify the exuvia.

dichotomous key: a key for the identification of organisms based on a series of choices between alternative characters. Source Credit: Merriam-Webster Dictionary.

The first couplet [1, 1′] is as follows.

1. No lateral spines on abdominal segments 8-9; western [2]
1’. Lateral spines present on segments 8-9; eastern [3]

No. 1 | Cordulegaster sp. | exuvia (ventral)

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

Since the preceding annotated image shows lateral spines on abdominal segments eight and nine (S8, S9), proceed to the third couplet [3, 3′].

3(1’). Palpal setae 4; usually 5 large and 5 small premental setae present; some setae on margin of frontal shelf spatulate (Fig. 391e) [erronea]
3’. Palpal setae 5-7; 5-9 large and 3-5 small premental setae present; all setae on frontal shelf slender, not spatulate (Fig. 391f) [4]

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

The preceding annotated image shows the inner side of the prementum. Four (4) palpal setae are present, plus five (5) large- and five (5) small premental setae. The premental setae on the lower-right side of the prementum seem to be more intact than the ones on the upper-left: the large premental setae are labeled using white numerals; the small premental setae are labeled using red numerals.

The setae on the frontal shelf are mostly missing, as shown below. It’s possible they were broken off either when the larva burrowed in stream sediment (personal correspondence, Sue Gregoire) or when I cleaned the specimen.

No. 3 | Cordulegaster sp. | exuvia (frontal shelf)

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

Genus and species

The number of palpal setae strongly indicates the specimen is an exuvia from a Tiger Spiketail dragonfly (Cordulegaster erronea). Further, the rudimentary ovipositor shown in Photo No. 1 indicates this individual is a female.

The face behind the mask

Do you remember the way the female exuvia looked with its mask-like labium in place? In my opinion, she looked exotically beautiful!

No. 4 | Cordulegaster sp. | exuvia (face-head)

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

Well, that was then and this now. The following photo shows the face and mouth of the exuvia after the face mask was pulled away from the face in order to count the setae on the inner side of the prementum. Look closely at the full-size version of the photo. Yikes, that’s the stuff of nightmares!

No. 5 | Cordulegaster sp. | exuvia (face and mouth)

Related Resource: Cordulegastridae exuvia, a blog post by Walter Sanford featuring an exuvia collected by Mike Boatwright.

Tech Tips

The following equipment was used to shoot macro Photo No. 2, 3 and 5: Canon EOS 5D Mark II digital camera, in manual mode; Canon MP-E 65mm Macro lens (set for 2x); and Canon MT-26EX-RT Macro Twin Lite. A Sunpak LED-160 Video Light (with a white translucent plastic filter) was used for some photos.

The following equipment was used to shoot macro Photo No. 1 and 4Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. An off-camera Fujifilm EF-X500 external flash unit and Sunpak LED-160 Video Light (with a white translucent plastic filter) were used for Photo No. 4. A Raynox DCR-250 close-up filter and Canon MT-26EX-RT Macro Twin Lite was used for Photo No. 1.

Adobe Photoshop CC 2017 was used to annotate selected images.

Copyright © 2018 Walter Sanford. All rights reserved.

How to calculate magnification

February 12, 2018

By definition, a true macro photo is one with a magnification of at least one-to-one (1:1, or 1/1), that is, one unit on the camera sensor is equal to at least one of the same units in the real world. Magnification (in-camera) can be calculated using the following formula.

Mc = size of subject on camera sensor / size of camera sensor

Both measurements must be expressed in the same units in order for the units to cancel during division.

For example, let’s look at the following “full-size” image of a Corduligastridae erronea exuvia. “Full-size” means the image is uncropped (4896 x 3264 pixels).

The photograph shown above was taken using a Fujifilm X-T1 digital camera, Fujifilm MCEX-11 extension tube, and Fujinon XF80mm macro lens. The specifications for the macro lens lists the maximum magnification as 1x. Question is, what is the actual magnification of the subject?

The X-T1 features an APS-C sensor (23.6 mm x 15.6 mm). The dragonfly exuvia is approximately 35 mm in length, or 3451 pixels out of 4896 pixels across the entire image.

Using two equivalent ratios, the following proportion can be used to solve for the length of the exuvia on the camera sensor, in millimeters (mm).

x mm / 23.6 mm = 3451 pixels / 4896 pixels

x = ~16.6 mm. In other words, the exuvia is ~16.6 mm wide on a camera sensor that is 23.6 mm across.

Calculate the in-camera magnification using the following formula.

16.6 mm / 23.6 mm = ~0.7x

The magnification of the subject is ~0.7x, meaning the size of the subject on the camera sensor is slightly smaller than the width of the camera sensor. Expressed another way, the in-camera image is ~7/10 life size.

1.19x is listed as the theoretical maximum magnification using an MCEX-11 extension tube mounted on the 80mm macro lens. If we round the spec’d magnification to ~1.2x, then it’s clear that the actual magnification of ~0.7x is less than advertised, meaning the lens/extension tube combination is capable of focusing more closely on the subject than my sample photo.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Cordulegastridae exuvia

February 6, 2018

My good friend Mike Boatwright, a fellow Virginian and extraordinarily good odonate hunter, collected an exuvia on 22 June 2017 in Amherst County, Virginia USA. Mike sent the exuvia to me for identification. This specimen is a member of the Family Cordulegastridae (Spiketails).

Photo No. 1 enabled me to see all of the critical field markers required to make an identification to the family level for this specimen. Here’s the decision tree I used to identify the exuvia as a spiketail dragonfly, based upon the excellent Vimeo video, Identifying dragonfly larva to family (8:06).

  • The specimen has a mask-like labium.
  • The margins of the labium have “deeply jagged, irregular teeth.”

Of the four families of dragonflies that feature a mask-like labium, the crenulations on the face of Corduligastridae are unmistakeable!

No. 1 | Cordulegaster sp. | exuvia (face-head)

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

The specimen is ~3.5 cm long (~1.4 in) and ~8 mm wide (0.3 in) at its widest. Notice the dorsal side of the exuvia is covered by sandy grit. The specimen will need to be cleaned in order to get a clearer view of the frontal shelf.

No. 2 | Cordulegaster sp. | exuvia (dorsal)

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

Photo No. 3 shows a ventral view of the exuvia.

No. 3 | Cordulegaster sp. | exuvia (ventral)

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

Photo No. 4 shows a closer view of the “rudimentary ovipositor,” located on abdominal segment nine (S9). An ovipositor is used for egg-laying by all adult damselflies and some species of adult dragonflies: females have this feature; males do not. Therefore, this individual is a female spiketail.

No. 4 | Cordulegaster sp. | exuvia (ventral, rudimentary ovipositor)

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

Photo No. 5 shows a closer view of the mentum, a two-segment hinged “jaw” that is used to grab food: the prementum is the segment of the labium closer to the mouth; the postmentum is the segment closer to the base of the head. Only the prementum can be seen in the following photo.

No. 5 | Cordulegaster sp. | exuvia (ventral, prementum)

Determining the genus and species

Although it’s easy to identify Cordulegastridae exuvia to the family level, it’s more challenging to identify a specimen to the species level. First, the exuvia must be cleaned in order to show the small hairs and brown dots on the frontal shelf. Second, the labium must be pulled forward to show the inside of the face mask in order to count palpal- and premental setae.

Related Resources

Tech Tips

The following equipment was used to shoot all of the macro photographs featured in this post: Fujifilm X-T1 digital camera; Fujifilm MCEX-11 extension tube; and Fujinon XF80mm macro lens. An off-camera Fujifilm EF-X500 external flash unit and Sunpak LED-160 Video Light (with a white translucent plastic filter) was used for Photo No. 1-3 and 5. A Raynox DCR-250 close-up filter and Canon MT-26EX-RT Macro Twin Lite was used for Photo No. 4.

Adobe Photoshop CC 2017 was used to annotate selected images.

Copyright © 2018 Walter Sanford. All rights reserved.


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