Archive for November, 2022

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. External gills (3) indicate 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).

Related Resources

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.

How to find stuff in my blog

November 15, 2022

There are many ways readers can find stuff in my blog.

Notice the text field labeled “search this site,” located at the top of the right sidebar. Enter a text string, press enter/return, and voilà — a list of “Search Results” shows many if not all blog posts related to the search string. For example, type “tiger spiketail” and you will see an index of several pages of blog posts in which the words “tiger spiketail” appear.

From there, you might click on one of the “Tags” that I add to blog posts. For example, click on Cordulegaster erronea, the scientific name for Tiger Spiketail dragonfly, and you will see the full-text version of all “Posts Tagged ‘Cordulegaster erronea.’

The right sidebar also includes a section called “Categories,” listed in alphabetical order. “Categories” are broader than “Tags” but they can be a good starting point for your seach. Some categories are more specific than others. For example, if you click on the category entitled ‘macro photography using 4x microscope objective‘ you will see fewer posts than if you click on ‘macro photography.’ The archive for each category shows full-text versions of all related blog posts.

Finally, there is a list of “Pages” located near the top of the right sidebar. Each page is a Web page that typically leads to a list of related resources. For example, if you click on “Photo Gear Talk” then you will see a page featuring links to some of the more useful blog posts that I have written about a variety of gear-related topics, such as “Continuous power sources – external and internal.” Many of the resources listed on the “Photo Gear Talk” Web page feature hard to find guidance that I think readers will find useful.

In my opinion, “Pages” are underutilized by readers of my blog. That’s regrettable because there’s a lot of good stuff on those pages. For example, my page entitled “Odonate Terminal Appendages” is one of the most complete resources of its kind on the Internet.

What have I missed? Please leave a comment if you know of other ways to mine the archives on my blog. Thanks and happy hunting!

Copyright © 2022 Walter Sanford. All rights reserved.

Depth of field

November 11, 2022

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.

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

Copyright © 2022 Walter Sanford. All rights reserved.

Focus bracketing using Panasonic “Post Focus”

November 8, 2022

It’s been quite a while since I experimented with focus bracketing using Panasonic “Post Focus.”

“Post Focus” is a feature available on select Panasonic cameras (such as my Panasonic Lumix DMC-FZ300 superzoom bridge camera) that enables the photographer to select different focus points after a shot is taken. That’s cool! Turns out “Post Focus” can be used to do focus bracketing / focus stacking too, and in my opinion that’s way cool!

When “Post Focus” is turned on, the camera actually records a single frame of 4K video at 30 fps (MP4 in 4:3 aspect ratio) as it cycles through the 49 focus points from front-to-back.

Since “Post Focus” records short video clips, continuous light sources such as my Sunpak LED-160 must be used to enhance/supplement ambient light.

I set up two scenes using the same studio “models”: the first was shot in landscape mode; the second in portrait mode.

Landscape mode.

As you can see, the lighting doesn’t look good. I usually use external flash units rather than continuous light sources. I need to work on that.

I didn’t edit either of the final composite images because my goal was to test to see whether all three subjects are in focus. They are.

Portrait mode.

Tech Tips

I programmed the Fn4 button to turn “Post Focus” on/off. [Editor’s Note: The default setting for Fn4 is LVF. LVF enables the user to switch between the monitor and viewfinder.]

The following camera settings were used: focal length = 4.5mm (28mm, 35mm equivalent); aperture = f/7.1; shutter speed = 1/80 s; ISO = 400. AF mode set for 49 points.

In order to create the preceding focus stacks, I opened two MP4 files in Adobe Photoshop. Next I exported video frames as individual files that can be imported into Photoshop for focus stacking. I prefer TIFF files rather than JPGs. Then the TIFF files were imported into Photoshop for focus stacking.

That’s an oversimplification of the process. Never fear — Photo Joseph does a good job of explaining the process in detail in the following YouTube video.

Related Resource: 4K Focus Stacking with Panasonic LUMIX Cameras – Presented by LUMIX Luminary Photo Joseph (7:34).

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 microscope objective forms an image at the bottom of the microscope eyepiece, according to Allan Walls in Macro Talk #17 (~8:30).]

The difference of 150 mm (160 mm – 10 mm = 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.

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.


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