Archive for the ‘extension tubes’ Category

Which family is it?

November 29, 2022

An odonate exuvia was collected by Cindy Haddon Andrews on 03 September 2022 along the James River, near the Maidens Boat Landing in Powhatan County, Virginia USA. This specimen is from a damselfly in Suborder Zygoptera.

Pattern recognition can be used to tentatively identify damselfly larvae/exuviae to the family level: the shape of the prementum is characteristic for each of the three families found in the mid-Atlantic region of the United States of America.

Your mission, should decide to accept it, is to identify the family to which the following damselfly exuvia belongs.

03 SEP 2022 | Powhatan County, VA USA | (exuviaventral side)

The camera lens was manually focused on the prementum, located near the anterior end of the exuvia.

Here is the same photo rotated 90° clockwise.

03 SEP 2022 | Powhatan County, VA USA | (exuviaventral side)

If you think you know the family, then please leave a comment. The correct answer will be revealed in a post update.

Related Resource: How to Identify Damselfly Exuviae to Family – a photo-illustrated identification guide by Walter Sanford.

Copyright © 2022 Walter Sanford. All rights reserved.

Archilestes grandis exuvia (female)

November 25, 2022

An odonate exuvia from a Great Spreadwing damselfly (Archilestes grandis) was collected by Edgar Spalding at a small private pond in Middleton, Wisconsin USA.

SEP 2022 | Middleton, WI | Archilestes grandis (exuvia, ventral side)

External gills (3), highlighted by a blue rectangle in the following annotated image, indicate the exuvia is from a damselfly in Suborder Zygoptera.

The camera lens was manually focused on the prementum, located near the anterior end of the exuvia (highlighted by a red rectangle). The overall shape of the prementum indicates this specimen is from Family Lestidae (Spreadwings); the unique shape of the palpal lobes (highlighted by a purple rectangle) indicates Genus Archilestes.

There are two species in Genus Archilestes in North AmericaArchilestes californicus; and Archilestes grandis. I think it’s reasonable to infer this individual is A. grandis since Wisconsin is far out of range for A. californicus.

SEP 2022 | Middleton, WI | Archilestes grandis (exuvia, ventral side)

This individual is a female, as indicated by the rudimentary ovipositor located on the ventral side of its abdomen, near the posterior end (highlighted by a green rectangle in the preceding annotated image).

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Copyright © 2022 Walter Sanford. All rights reserved.

George Washington

November 18, 2022

My customized 4x magnification macro rig was used to photograph a small part of a quarter, that is, a 25-cent coin in U.S. currency.

A small part of a quarter (25-cent coin in U.S. currency).

The face/head of George Washington appears on one side of the coin. George Washington was the first president of the United States of America.

Tech Tips

The preceding photo …

  • was shot handheld (not recommended for this camera rig). A single external flash unit was used to light the photo.
  • is a “one-off,” meaning the photo isn’t focus-stacked. At a magnification of 4x the depth of field is extremely shallow. The net result is relatively little of the photo appears to be acceptably in focus.
  • is “full frame” (6240 × 4160 pixels), meaning it is uncropped.
  • is an unedited JPG file, straight out of the camera.

Copyright © 2022 Walter Sanford. All rights reserved.

Theory into practice

November 4, 2022

What is the “neighborhood play” in baseball?

The “neighborhood play” is a colloquial term used to describe the leeway granted to middle infielders with regards to touching second base while in the process of turning a ground-ball double play. Though it is not explicitly mentioned in the rulebook, middle infielders were long able to record an out on the double-play pivot simply by being in the proximity — or neighborhood — of the second-base bag. Source Credit: Neighborhood Play, MLB Glossary.

And so it is with the 3-D printed plastic “lens” adapter I bought recently for my Fujifilm X Series cameras. The lens adapter, assembled so that it includes all three pieces (photo credit: Nicholas Sherlock Photography), puts a 4x magnification microscope objective in the neighborhood of where it should be for optimal performance.

Naturally I was curious to know exactly where the microscope objective should be mounted  and whether the “lens” actually performs better at that distance.

Theory

I consulted the experts at amateurmicrography.net and asked for guidance specifically for my Fujifilm X-Series mirrorless digital cameras. Thanks to Mr. Rik Littlefield for his quick reply!

First, Rik referred me to an article from the Frequently Asked Questions (FAQ) forum: FAQ: How can I hook a microscope objective to my camera? In this blog post, I will refer to the following annotated image — the first one in the FAQ article.

Photo Credit: Rik Littlefield.

Let me summarize Rik’s detailed answer to my question.

Microscope objectives like the two 4x magnification microscope objectives I own and the 10x objective shown in the preceding annotated image, are designed to work with microscopes featuring a mechanical tube length of 160 mm minus 10 mm for the microscope’s eyepiece. The difference of 150 mm is known as the optical tube length, and in photomicrography, is the distance the microscope objective should be mounted from the plane of the camera sensor (as shown above).

Photo Credit: B&H Photo. Fujifilm X-T5 camera (body only).

Fujifilm X Series mirrorless digital cameras have a flange focal distance (FFD) of 17.7 mm, meaning the distance between the plane of the camera sensor and the face of the lens mount on the front of the camera body is 17.7 mm (as shown above). 150 mm – 17.7 mm = 132.3 mm. 132.3 mm is the ideal mounting distance between the “lens” and the outside of the camera body.

The next photograph shows the customized 4x magnification macro rig I was able to cobble together using photography gear I had on-hand already, following Rik’s recommendations. Briefly, several extension tubes were used to mount the “crop” configuration of my 3-D printed plastic lens adapter and 4x magnification microscope objective on a Fujifilm X-T3 digital camera.

My customized 4x magnification macro rig.

Remember, my goal was to move the microscope objective 132.3 mm from the face of the camera body. I combined two 16mm extension tubes and one 10mm extension tube (42 mm total) with the “crop” configuration of the plastic lens adapter (~90 mm from back to front). 42 mm + 90 mm = 132 mm. That’s “good enough for government work” as we say in Washington, D.C.

In contrast, the full size 3-D printed plastic lens adapter moves the microscope objective 142 mm from the face of the camera body — in the neighborhood but a little farther than it should be.

Gear I used

The following equipment list includes all items mounted on the Fujifilm X-T3 camera body shown in the preceding photo.

Finally, a few words about extension tubes designed for Fujifilm X Mount cameras.

Fujifilm makes two extension tubes, as of this writing: the MCEX-11; and MCEX-16. I bought both the 11mm and 16mm extension tubes, although in retrospect, the 11mm is the only one I recommend buying (based upon my usage). It’s good to have found a purpose for the MCEX-16.

When I bought my Fujifilm X-T1 camera more than 10 years ago, Fujifilm didn’t offer extension tubes for sale. “Fotasy” was the first third-party company to sell extension tubes with electronic contacts for Fujifilm X Mount cameras. I bought both sizes that were available (10mm and 16mm) and they worked well, that is until Fujifilm released their proprietary extension tubes — at that point the Fotasy extension tubes were incompatible with newer lenses sold by Fujifilm. Although my older Fotasy extension tubes don’t work with newer Fujifilm lenses, they are perfect in this case because my customized 4x magnification macro rig is all manual all the time.

Gear that could be used (instead of my rig)

What if you don’t have a “junk drawer” of old, unused camera gear like me? Rik Littlefield recommended the following items that could be used for mounting a 4x microscope objective on a Fujifilm X Series camera.

Theory into practice

My customized 4x magnification macro rig was used to photograph a small part of a dime, that is, a 10-cent coin in U.S. currency.

All three photos …

  • were shot handheld (not recommended for this camera rig). A single external flash unit was used to light each photo.
  • are “one-offs,” meaning they aren’t focus-stacked. At a magnification of 4x the depth of field is extremely shallow. The net result is relatively little of each photo appears to be acceptably in focus.
  • are “full frame” (6240 × 4160 pixels), meaning they are uncropped.

For scale, the letters “DIM” are approximately 5 mm wide on the actual coin.

A small part of a dime (10-cent coin in U.S. currency).

A small part of a dime (10-cent coin in U.S. currency).

A small part of a dime (10-cent coin in U.S. currency).

Are these photos better than the test shots I took when I first got the 3-D printed plastic lens adapter? You be the judge, but I think they are qualitatively better.

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Copyright © 2022 Walter Sanford. All rights reserved.

Rube Goldberg 4-5x macro photography rig

October 25, 2022

By now you might be wondering “What does your Rube Goldberg 4-5x macro photography rig look like?”

The first photo shows an AmScope 4x microscope objective mounted on a plastic lens adapter designed and 3-D printed by Nicholas Sherlock.

AmScope 4x microscope objective mounted on “lens” adapter.

The next photo shows a close-up view of the AmScope 4x microscope objective.

AmScope 4x microscope objective mounted on “lens” adapter.

The next two photos show the plastic lens adapter and microscope objective mounted on my Fujifilm X-T3 mirrorless camera. A Fujifilm 11mm extension tube is mounted between the camera body and lens adapter. More about that in a follow-up blog post.

3-D printed plastic “lens” adapter mounted on Fujifilm X-T3 camera.

A close-up view of the Reakway 4x microscope objective is shown below.

Reakway 4x microscope objective mounted on the “lens” adapter.

Similar microscope objectives

Did you notice two similar microscope objectives are shown in the preceding photos? I decided to buy both of the “lenses” recommended by Nick Sherman — since they are priced so affordably I was curious to see whether one works better than the other. As far as I can tell during limited testing, both microscope objectives perform equally well.

One objective has a smooth barrel …

Photo Credit: AmScope.

The other one has a knurled barrel.

Photo Credit: AliExpress / Reakway.

The lenses are recessed from both ends of the barrel, providing protection against scratching the glass. [Photo Credits: AliExpress / Reakway.]

Both objectives have similar information printed on the barrel.

What does “Plan” mean?

A plan (or planar) objective corrects better for color and spherical aberration than either the semi-plan or the achromatic objective. Plan objectives have a flat field about the center 95% of the image. They also often have larger working distances. Source Credit: What is the difference among achromatic, semi-plan, and plan objectives? Celestron, LLC.

What do the numbers mean?

Microscope objective lenses will often have four numbers engraved on the barrel in a 2×2 array. The upper left number is the magnification factor of the objective. For example, 4x, … The upper right number is the numerical aperture of the objective. For example 0.10, … The lower right number (if given) refers to the thickness of the glass cover slip (in millimeters) assumed by the lens designer for best performance of the objective. Example: 0.17. The lower left number is the tube length in millimeters.

Sometimes objectives have a color ring to aid in identifying the magnification: black (1x), brown (2x), red (4x), …

Source Credit: What do the numbers on the barrel of the microscope objective mean? What about the letters DIN and JIS? Celestron, LLC.

I love the little plastic bottles that are used for storing microscope objectives safely.

Photo Credit: AliExpress / Reakway.

“Crop” configuration

The 3-D printed plastic lens adapter that I bought for my Fujifilm X-Series cameras is comprised of three parts that screw together. Nick Sherlock calls this version the “crop design.”

The crop design is for Sony E, Canon EF-S, Micro Four Thirds, Fujifilm X, or Nikon F crop cameras (or full-frame cameras which have been switched to crop mode) which has a segment of tube you can remove to shorten the tube.

For objectives which cast a big enough image circle, removing this middle tube allows you to reduce the magnification and focus at a greater distance (for the 4x objective I tested this reduced magnification from 4x to 2.75x, and increased working distance from about 28 to 31mm).

Source Credit: Microscope adapter for 4x macro photography with Sony E/FE, Canon EF/EF-S, Nikon F, Nikon Z, Fuji X, M4/3, M42 cameras, by thenickdude.

My Rube Goldberg 4-5x macro photography rig is even more Rube Goldergier than I realized when I bought it. As it turns out, the rig can be configured as both a 2.75x and 4-5x magnification macro photography rig. Very clever design, Nick Sherlock!

I tested the “crop” configuration and am pleased to report it works as advertised. My first impression is 2.75x magnification should prove to be more practical for use in the field than 4-5x. More later in a follow-up blog post.

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

Iberian odonate larvae

September 16, 2022

During late-October 2021, I was contacted by Miguel A. Conesa-García, PhD, Profesor Tutor Biología, Diversidad Animal, Ciencias Ambientales, UNED-Málaga.

Miguel was working on finishing the second edition of his book about odonate larvae in the Iberian Peninsula (Spain and Portugal). When Miguel was almost finished, an adult male Wandering Glider dragonfly (Pantala flavescens) was spotted in Spain. P. flavescens is a new species of odonate for the region, so Miguel decided to add the new discovery to the species list in his book.

Cover photo, courtesy Amazon Books.

The following screen capture shows the search string I used to find the book on Amazon.

Screen capture, Amazon Books.

The book is richly illustrated with beautiful photos and diagrams. It’s abundantly evident I could learn a lot from the book — I wish there were an English Edition!

Miguel requested permission to use a photo of a Wandering Glider exuvia in my photoblog, published on 14 November 2018. I was, of course, willing to help.

Page excerpt from Miguel’s book, featuring my photo.

I’m mentioned in the acknowledgements at the end of the book. Regrettably my first name is misspelled and the Web address cited is no longer current. I took the liberty of annotating the page from Miguel’s book to provide the correct information.

Acknowledgements, p. 539 (annotated).

Acknowledgements, p. 539 (original).

Migratory Dragonflies

Wandering Glider is one of at least five major species of dragonflies known to be migratory in North America. P. flavescens is the only species of odonate known to occur on every continent except Antarctica.

The exuvia that I photographed is the “cast skin” from an odonate larva (nymph) that was collected in the field by Andy Davidson, a graduate student at Virginia Commonwealth University in Richmond, Virginia USA. Andy reared the larva in the laboratory as part of a research project entitled “Predator-Prey Interactions in a Changing World.”

Part of the value in rearing odonate larvae in the laboratory is knowing with certainty that an exuvia is from a particular species. This is perhaps the reason that Miguel chose to use my photo.

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

Dark and moody

November 19, 2021

I spotted an emergent Uhler’s Sundragon (Helocordulia uhleri) during a photowalk along a mid-size stream at an undisclosed location in Prince William County, Virginia USA. The following photograph shows the exuvia from which the teneral adult emerged.

13 APR 2021 | PNC. Wm. County, VA | Uhler’s Sundragon | exuvia (ventral)

In the opinion of the author, larvae (nymphs)/exuviae from Family Corduliidae (Emeralds) and Family Libellulidae (Skimmers) can be challenging to differentiate and identify to the family level.

One way to differentiate Emerald from Skimmer larvae/exuvia is to look for a “ventromedial groove” in the prementum: it’s probably Corduliidae (Emeralds) if there is a ventromedial groove; it’s probably Libellulidae if there isn’t.

Look closely at a version of the preceding photo that was reformatted, rotated, and cropped to show an enlarged view of the prementum. You should notice a ventromedial groove on the basal half of the prementum, indicating this specimen is a member of Family Corduliidae (Emeralds).

13 APR 2021 | PNC. Wm. County, VA | Uhler’s Sundragon | exuvia (ventral)

Three raised structures on the underside of the prementum remind me of the hood ornament on a 1949 Lincoln automobile. (No, I wasn’t alive in 1949!)

Related Resources

Tech Tips

One reason I underexposed the photo is to add definition to the ventromedial groove and avoid overexposing the black background.

I prefer a white background for photographing odonate exuviae. Using a black background proved to be more challenging than I expected. More later in a follow-up blog post.

Copyright © 2021 Walter Sanford. All rights reserved.

Comet Darner exuvia: annotated images

October 8, 2021

My last blog post was a “sketch pad” of test shots of an exuvia from a Comet Darner dragonfly (Anax longipes) collected by Stanley Caveney on 19 July 2021 from a pond at MeadowWoods in West Elgin, Ontario, Canada. All of the shots in that post are unedited JPGs straight from my camera. This post features edited versions of the RAF (raw) files from that photo shoot, including some images with value-added annotations.

Lateral view

I considered annotating the first photo but decided to allow it to stand on its own as the latest addition to my Odonart© Portfolio.

Comet Darner (Anax longipes) | exuvia (lateral)

Ventral view

I used Adobe Photoshop to create a composite image that features the best parts of two photos from the sketch pad.

This specimen is from a male Comet Darner, as indicated by its vestigial primary- and secondary genitalia. The inset photo shows a clear view of the vestigial hamuli (secondary genitalia) that are partially obscured in the background photo.

Comet Darner (Anax longipes) | exuvia (ventral)

Prementum

The last photo 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.

Comet Darner (Anax longipes) | exuvia (prementum)

The preceding annotated image of the prementum includes labels for the moveable hooks (2 of 2) and palpal lobe (1 of 2). Notice that A. longipes palpal lobes are squared off, in contrast with the more rounded shape of the labial palps of Common Green Darner (Anax junius).

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Comet Darner exuvia: photo sketch pad

October 5, 2021

Sometimes I shoot test shots of an odonate exuvia that are used to plan the final shots I have in mind for an identification guide featuring annotated photos.

All of the shots in this post are unedited JPGs straight from my camera, with the exception of the first ventral view (cropped to remove a distracting element from the composition).

Lateral view

I started with a lateral view of an exuvia from a Comet Darner dragonfly (Anax longipes) exuvia collected by Stanley Caveney on 19 July 2021 from a pond at MeadowWoods in West Elgin, Ontario, Canada.

Comet Darner (Anax longipes) | exuvia (lateral)

Ventral view

The next two photos show my frustratingly poor attempts to pose the specimen for shots of the ventral side of the exuvia. Every time I positioned the subject the way I wanted, it rolled over before I could take a shot!

Comet Darner (Anax longipes) | exuvia (ventral)

The two shots combined show the vestigial primary- and secondary genitalia that indicate this specimen is from a male Comet Darner. Yeah, I know it would help to annotate those parts of its anatomy, but that’s the next step. In the meantime, please follow the embedded hyperlink shown above and you might be able to figure out what I’m saying.

Comet Darner (Anax longipes) | exuvia (ventral)

Prementum

The last photo shows a closer view of the prementum. My goal was to get a better look at the labial palps. Again, annotations would help, but if you know what I’m talking about then you can see the palpal lobes are squared off.

Comet Darner (Anax longipes) | exuvia (prementum)

Copyright © 2021 Walter Sanford. All rights reserved.

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.


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