Post update: What is it?

The mystery object shown in my last blog post is one of my prized possessions — an enamel lapel pin from the National Oceanographic and Atmospheric Administration (NOAA).

NOAA enamel lapel pin.

The About Me permanent page on my blog, linked from the top of the “Pages” section in the right sidebar, features the following quote.

For more than a decade, I was actively involved with several education outreach initiatives of the American Meteorological Society. Source Credit: About Me page.

As a result of generous funding from the National Science Foundation (NSF), the National Weather Service NWS), and the American Meteorological Society (AMS), I was able to participate in summer workshops for K-12 teachers at many NOAA/NWS facilities such as the National Weather Service Training Center, the NOAA/NWS Storm Prediction Center, the NOAA National Severe Storms Laboratory, the Cooperative Institute for Meteorological Satellite Studies, and the National Center for Atmospheric Research, to name a few. There I received training that enabled me to serve as an AMS Atmospheric Resource Agent for the Commonwealth of Virginia.

I don’t remember exactly when and where I was given the NOAA lapel pin but it’s a treasured memento of a period in my life when I learned a lot from some of the top experts in NOAA, and I experienced significant professional growth.

Copyright © 2023 Walter Sanford. All rights reserved.

What is it?

Ladies and gentlemen, children of all ages. It’s time for another exciting episode of “What is it?”

I will reveal that both photos are “one offs” (not focus stacked composite images) that show different parts of the same object, photographed with a 4x microscope objective mounted on my Fujifilm X-T3.

If you think you know what is shown in these photos, then please leave a comment. The answer will be revealed in a post update.

Copyright © 2023 Walter Sanford. All rights reserved.

I love it when a plan comes together!

Do you remember The A-Team, a classic 1980s TV show? One of Colonel John “Hannibal” Smith’s catch phrases was “I love it when a plan comes together!” So do I.

In my last blog post, I wrote the following …

Look closely and you should notice a few places that appear to be artifacts resulting from the focus stacking process. (Look around the borderline between the toy dinosaur and NSTA plastic ruler.) … I must admit this is cause for concern. Source Credit: More testing, AUTO FOCUS BKT, by Walter Sanford.

Could you tell I was more than a little discouraged by the discovery of artifacts in my focus-stacked composite images? I was. So I devised a plan for isolating the cause of the problem and finding a solution.

The plan

First I looked at the source images for the composite images. I didn’t see the same artifacts in any of the JPG files used to create the focus stacks, so I knew that in-camera focus bracketing was working properly in my Fujifilm X-T5.

Next I re-rendered (is that a word?) the source images using Helicon Focus Method A and Method C. My hypothesis, based upon limited experience and knowledge gained by following the “Focus stacking – Helicon Focus” Facebook group, was that rendering Method C would work without creating artifacts.

Turns out I was right. Look closely at the full-size version of the following focus-stacked composite image and you should see the artifacts are gone. And that’s a good thing, because as far as I can tell using the retouching tools in Helicon Focus means “you’re entering a world of pain.” (Source Credit: John Goodman as Walter Sobchak in “The Big Lebowski.”)

Toy dinosaur focus stack: two flashes; 74 frames; rendering Method C.

Buoyed by my success with re-rendering the source images for the composite image of a toy dinosaur, I used Method C to re-render the source images for the composite image of a toy lizard. Same result: Artifact problem solved!

Toy lizard focus stack: one flash; 96 frames; rendering Method C.

So now both composite images are tack-sharp from front-to-back and artifact-free. Yep, I love it when a plan comes together! And looking at the bigger picture, now I know for sure that Fujifilm in-camera AUTO FOCUS BKT works as I hoped and works well. That’s a win-win!

Why do we focus stack?

The composite image of the toy dinosaur, shown above, was created using 74 unedited JPGs straight out of my Fujifilm X-T5 digital camera. All of the photos were shot using an aperture of f/11.

The following slideshow was created using the first, middle, and last photos in the set (frames 01, 37, and 74). The focus point moves from the tip of the head, to somewhere along the body of the toy dino, and to the tip of its tail. In each of the photos, notice how little of the toy and ruler are acceptably in focus — even at a relatively small aperture of f/11. And that, ladies and gentlemen, is why we focus stack!

This slideshow requires JavaScript.

Related Resources

• More testing, AUTO FOCUS BKT – a blog post by Walter Sanford.
• AUTO FOCUS BKT – another blog post by Walter Sanford.
• Helicon Focus online documentation

Copyright © 2023 Walter Sanford. All rights reserved.

AUTO FOCUS BKT (plus Post Update)

Let me say at the outset I love my Fujifilm X-T3 digital camera. That being said, I bought the Fujifilm X-T5 almost as soon as it was released.

There are many reasons I decided to buy the Fujifilm X-T5 but the number one reason is the X-T5 features both Auto- and Manual mode focus bracketing while the X-T3 is Manual only.

At some point I’ll revisit MANUAL mode focus bracketing, but this post will focus on AUTO FOCUS BKT. Using AUTO FOCUS BKT, the photographer sets the beginning and ending focus points and the camera selects the step size and number of frames automatically.

Sample output

The following composite image was created using Helicon Focus to focus stack 96 JPG photos taken automatically using my Fujifilm X-T5 set for AUTO FOCUS BKT. The composite image was created using unedited JPGs straight out of the camera.

Toy lizard plus NSTA plastic ruler.

As you can see, both the toy lizard and NSTA plastic ruler are in focus from front-to-back without any focus banding. The process worked surprisingly well and could be a game-changer for creating focus stacks of relatively larger macro subjects.

Step-by-step instructions

The next two images are screenshots from  the online version of the Fujifilm X-T5 Owner’s Manual. From the Table of Contents, click on “Shooting Menus”; from the sub-menu that appears on screen, click on “Shooting Setting (Still Photography).” Click on Drive Setting; navigate to the section entitled “FOCUS BKT SETTING” and look for “AUTO.”

Steps 1-3 …

Image Credit: Fujifilm X-T5 Owner’s Manual.

Steps 4-5 …

Image Credit: Fujifilm X-T5 Owner’s Manual.

Here’s my interpretation of the preceding outtakes from the Fujifilm X-T5 Owner’s Manual. I suggest you follow the set of step-by-step directions that makes more sense to you, although I think they are complementary.

First, a few words of caution about something that can and probably will trip you up the first time you try focus bracketing, using either MANUAL- or AUTO mode. (That’s the voice of experience talking.) You need to make settings in several places including one setting on the camera itself and two MENU settings. All of those settings are highlighted in boldface red text.

1. Set the “Drive dial” [physical dial located under “Sensitivity dial” (ISO)] for BKT.
2. Press MENU/OK. [press left trackpad button] Select Drive Setting (camera icon) > [press right trackpad button]
3. BKT SETTING > [press right trackpad button]
4. BKT SELECT > [press right trackpad button] FOCUS BKT [press OK]
5. [bottom trackpad button] Select FOCUS BKT > [press right trackpad button] AUTO > [press right trackpad button] INTERVAL [set for 10 s [press OK]
6. SET POINT A – Use the “Focus stick (focus lever)” to move the focus point to your desired location. Press the button for back-button focus [AF ON button, by default]. [press OK]
7. SET POINT B – Relocate the focus point. Press the button for back-button focus [AF ON button, by default]. [DO NOT press OK!]
8. BACK, END – Press the DISP/BACK button one time until you see the menu screen where you choose either “MANUAL or AUTO.” [This step seems a little counterintuitive to me, but it works.]
9. Press the “Shutter button.” I recommend a 10 s timer; there is a countdown for the first shot only.

When you are setting focus for Point A and Point B, you can use any method that works for you including simply turning the focus ring on the camera lens. I prefer to use back-button focus. When the camera is set for Manual focus mode (M) the “AF ON” button is used for back-button focus by default. Try it — I think you’ll like it and it just works right out of the box.

I set Point A for the tip of the lizard’s nose and Point B for the tip of its tail.

Tech Tips

X-T5 camera/lens settings: f/11; ISO 200; 1/250 s. White balance set for AUTO WHITE PRIORITY WBW. Single point focus. Number of Focus Points set for 425. “Focus mode selector” set for “M” (Manual focus).

Off-camera lighting:

• Godox XProF flash trigger
• Godox MF12: Modeling light = 10/10; flash power ratio = 1/8.

Bear in mind I didn’t really worry about lighting the subjects properly. I chose to use one external flash unit that I knew from experience would work reliably at 1/8 power. I’m pleased to report there weren’t any “dropped frames” due to flash failure.

Interval: 5 s ← Note: The built-in camera timer doesn’t work when using focus bracketing (except for the first photo) so I recommend you increase the  Interval to 10 s in order to give your camera time to settle between shots and plenty of time for your external flash units to power-cycle.

Subject: Toy lizard plus NSTA ruler = 96 frames (selected by camera automatically).

Background/”stage”: White reference card from a Vello White Balance Card Set (Small), and NSTA plastic ruler.

What are the take-aways?

My goal was to test the Fujifilm in-camera photo bracketing process using “AUTO” mode.  Zoom in to look at the full-size image — the detail is impressive! I’d say the test was a complete success. Well, mostly successful. For details, see “More testing…” under Related Resources.

Related Resources

• Focus Bracketing / Stacking with Fuji XT4 NEW AUTO Feature Stack w/ Photoshop or Helicon Focus, by The Magical Landscape (13:02). AUTO FOCUS BKT works exactly the same way in both the Fujifilm X-T4 and X-T5.
• More testing, AUTO FOCUS BKT – another blog post by Walter Sanford.
• I love it when a plan comes together! – the final blog post in what turned out to be a three-part series.

Post Update

Chris Lee, also known as “pal2tech,” released a related YouTube video after I published my blog post: “Why I LOVE This Fujifim Lens! (30mm Macro),” by pal2tech (11:26). Although the main theme of the video is a detailed review of the macro lens, there is an embedded segment related to how to use AUTO FOCUS BKT and Helicon Focus beginning at the 05:05 minute mark and ending at ~07:47: “How To Focus Stack With Fujifilm Macro Lens.” Well done, Chris!

It’s worth noting I disagree with Chris’s recommendation of the Fujifilm XF30mm F2.8 R LM WR Macro lens. Regular readers of my blog know I’m all about macro photography and don’t need much of an excuse to buy more gear. I considered this lens carefully when it was announced and rejected it as a bad fit for my needs.

Chris has valid reasons for liking the lens and I have valid reasons for disliking it — we just disagree, that’s all. For example, Chris raves about how close you can get to the subject with this lens. Sounds good, but the reality is a small working distance makes it much more challenging to light the subject properly. And Chris readily concedes the lens isn’t perfect, optically speaking.

Bottom line: I strongly recommend the tutorial segment of Chris’s video while cautioning my readers to carefully consider whether this lens would be a good fit for your macro photography needs.

Copyright © 2023 Walter Sanford. All rights reserved.

L-bracket for Fujifilm X-T5

In a recent blog post, I said …

l use Arca Swiss L-brackets for all of my cameras. Good L-brackets are designed so the bracket doesn’t block any camera doors or ports. But I don’t have one for the [Fujifilm] X-T5 because it’s new enough that the selection of compatible L-brackets is poor. Source Credit: Walter Sanford, Comedy of Errors.

My urgent need for an L-bracket trumped my anxiety about ordering one from AliExpress in China. I decided to buy an L-bracket for my X-T5 from the “GoGlory Store.” US $27.55 plus free shipping helped to incentivize me. I placed my order on 12 March 2023; it was delivered on 20 March. Shipment from China to the east coast of the United States in eight (8) days was a pleasant surprise!

The L-bracket is well-made and fits my Fujifilm X-T5 perfectly without extending the vertical rail (as shown in the top photo, below).

Photo Credit: “GoGlory Store.”

The bracket comes with two Allen wrenches: a larger wrench (shown above); and a smaller one. The “GoGlory Store” Web page says the Allen wrenches are magnetic; they aren’t. Look closely at the full-size version of the preceding photos. Notice two small silver circles on the bottom of the horizontal rail — those are magnets in a groove that fits the larger Allen wrench.

The larger wrench is used to tighten/un-tighten a larger bolt that connects the L-bracket to the 1/4″-20 threaded tripod socket of your camera. The same bolt has a groove for a flat-head screwdriver.

The larger Allen wrench is also used to tighten/un-tighten a slightly smaller bolt that enables you to extend/contract the length of the L-bracket. That bolt does not have a groove for a screwdriver.

The smaller Allen wrench is used for two small bolts that enable you to remove the vertical rail completely.

Battery-chamber door

The following photo shows the L-bracket mounted on my Fujifilm X-T5; the opening in the horizontal rail enables the camera battery-chamber door to open/close freely without removing the L-bracket.

L-bracket, showing opening for camera battery-chamber door.

Camera Connectors (side doors)

The next photo shows the vertical rail of the L-bracket and the left side of my camera. The large cut-out in the L-bracket enables easy access to two small doors on the left side of the camera, and doesn’t block the built-in speaker. Both doors to the camera connectors are open in the following photo.

L-bracket, showing cut-out for camera connectors (side doors).

The vertical rail features four 1/4″-20 threaded sockets (taps) for mounting camera accessories.

What are the take-aways?

During limited testing, I am completely satisfied with the L-bracket I bought from AliExpress. Really, how often do you hear me say that about camera gear? A well-made product that does what it’s supposed to do, all for a good price plus free shipping — what’s not to like?

Copyright © 2023 Walter Sanford. All rights reserved.

Making progress (on a steep learning curve)

OK, let me say right at the outset that using a manual focus rail like my new-ish NiSi NM-200 to create a 328-photo focus stack is insane! So I regrouped, made a new plan, and conducted some tests.

I discovered, albeit too late, that I needed to shoot a lot of  photos for my last focus stack because I chose to use an aperture of f/8 and the “safe step size” for f/8 (at 1x magnification) is 40 µm (micrometers, or microns) — a relatively small step size.

In contrast, at 1x magnification the safe step size for f/11 is 800 µm — during limited testing that seems to be the sweet spot for creating focus stacks that look fairly good using fewer photos.

Canon EOD 5D Mark II DSLR camera plus Canon EF 100mm macro lens (1x, f/11)

The following composite image was created from 20 photos.

The background is the non-reflective side of a piece of black plastic. It’s textured surface appears to be a bad fit for macro photography — notice lots of little white specks on the background. Not good.

f/11 | 1/200 s | ISO 100 | Manual WB (Flash)

But wait, there’s one more thing. Did you notice the copper penny hiding underneath the quarter? Well, it was supposed to be hiding. I borrowed the idea from another photographer whose name I can’t remember. The point is to create some visual relief for the coin in the photo. The plan might have turned out OK if I’d noticed the misalignment of the penny before I did the focus bracketing.

Fujifilm X-T5 mirrorless digital camera plus Fujinon 80mm macro lens (1x, f/11)

The following composite image was created from 26 photos.

For the background, I used the white reference card from a Vello White Balance Card Set (Small). I set the white balance for AUTO WHITE PRIORITY WBW — a new setting (at least new to me) that’s supposed to result in whiter whites.

f/11 | 1/250 s | ISO 125 | WBW

The subject is in focus from back-to-front, and I like the white background. I think this is the best composite image I’ve created so far, but as always, you be the judge.

Fujifilm X-T5 mirrorless digital camera plus Fujinon 80mm macro lens (1x, f/11)

The following composite image was created from 21 photos.

For the background, I used the black reference card from a Vello White Balance Card Set (Small). I think it looks better than the textured black plastic background in the first photo, although I think the white background looks best.

f/11 | 1/250 s | ISO 125 | WBW

Pixel-peepers will notice the far end of the nickel isn’t as sharp as the rest of the coin. That’s because a man-caused disaster forced me to leave out the first two photos in the set. I hope the man responsible for this sloppy work will be held accountable for his actions!

Tech Tips

I think it’s worth noting that all three composite images were created using unedited JPGs straight out of the camera. All of the composite images could have been improved by making a few edits to the RAW files such as adjusting exposure, increasing contrast, and adding a little sharpening, to name a few.

In these test cases, I was looking for focus banding caused by using a step size that’s too big and glitches caused by Helicon Focus, the focus stacking software I used. As far as I can see, no problems.

My NiSi NM-200 is mounted on a Manfrotto 405 3-Way, Geared Pan-and-Tilt Head. The camera line of sight was inclined at a 45° angle relative to the staging surface. That’s less important in this case and more important for an upcoming review of the NiSi NM-200 focus rail.

Both cameras were set for manual exposure. Both lenses were set for manual focus; the combination of manual focus and back-button [auto]focus gives me the best of both worlds.

I use single point focus nearly all the time. I moved the focus point to the farthest point of each subject, then used back-button focus to autofocus on the subject and shoot a photo. Without changing focus from the first photo, I used the focus rail to move across the subject from back-to-front in 800 µm increments (eight numbered increments on the NiSi larger adjustment knob), taking a photo at each step.

More light is required for proper exposure at f/11 than f/8. I used one Sunpak LED-160, one Godox TT685C external flash unit (plus Altura flash modifier), and one Godox MF-12 external flash to light the first subject (Virginia quarter). Two Sunpak-160s and two Godox TT685C external flash units (using Altura and Lastolite flash modifiers) were used to light the last two subjects (quarter and nickel coins).

Related Resources

• Zerene Stacker DOF Calculator
• Fujifilm Colors: Auto White vs Auto Ambience, by pal2tech (12:47)
• Helicon Focus – Quick Start on Mac OS, by HeliconSoft (2:20)

Copyright © 2023 Walter Sanford. All rights reserved.

GW revisited

The following test shot shows part of a quarter, that is, a 25-cent coin in U.S. currency. I took the shot when I was testing my new NiSi NM-200 manual focus rail.

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 using my Fujifilm X-T3 camera and Laowa 25mm Ultra Macro lens. (I bought the Canon version of the Laowa lens. It’s mounted on my X-T3 using the X-mount adapter available from Laowa.) The lens was set for 2.5x magnification and an aperture of f/4, the “sweet spot” for this lens. 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 2.5x the depth of field is extremely shallow. The net result is not all 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 © 2023 Walter Sanford. All rights reserved.

5x magnification

What does 5x magnification look like?

The following photos are test shots that were taken using an AmScope 4x microscope objective mounted on my Fujifilm X-T3 digital camera with a plastic lens adapter designed and 3-D printed by Nicholas Sherlock. The actual magnification of the “lens” is between 4x and 5x due to the design of the adapter. The aperture of the lens is fixed, somewhere between f/4 and f/5.

All of the photos …

• were shot handheld (not recommended for this camera rig), except for the last two that were shot using a tripod. A single external flash unit was used to light each photo.
• are “one-offs,” meaning they aren’t focus-stacked. At a magnification of 5x the depth of field is extremely shallow. The net result is little of each photo will appear to be acceptably in focus.
• are “full frame” (6240 × 4160 pixels), meaning they are uncropped.
• are unedited JPG files, straight out of the camera.

The first photo shows a small part of a “granite” countertop. The word granite appears in quotes because the countertop might be made of some type of synthetic material.

The next photo shows the left eye of the “Made in the Shade” toy monkey, one of my favorite studio models.

The following photo shows part of a Metro SmartTrip fare card.

The next two photos show a penny, that is, a 1-cent coin in U.S. currency.

The next photo shows the last two digits of a 1996 quarter, that is, a 25-cent coin in U.S. currency.

The last two photos show part of an exuvia from Family Calopterygidae (Broad-winged Damselflies). The ventral side of the head is shown in both photos. The first photo is focused on the eye; the second photo is focused on the prementum.

The specimen was collected by Cindy Haddon Andrews on 03 September 2022 along the James River, near the Maidens Boat Landing in Powhatan County, Virginia USA.

Tech Tips

I talked about “manual” and “automatic” lens adapters in my last blog post. In order to use a manual lens adapter such as either my Laowa EOS-FX or the plastic adapter designed by Nick Sherlock, my Fujifilm X-T3 digital camera must be set so that “Shoot Without Lens” is on. This enables shutter release when the camera “thinks” no lens is attached.

Press the “Menu/OK” button / select SET UP (wrench icon located in the left sidebar) / choose BUTTON/DIAL SETTING / select SHOOT WITHOUT LENS (ON).

Copyright © 2022 Walter Sanford. All rights reserved.

Iberian odonate larvae

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

• Test shots: Pantala flavescens exuvia.
• Field Guide to Migratory Dragonflies, by Migratory Dragonfly Partnership.

Copyright © 2022 Walter Sanford. All rights reserved.

Fujifilm/Fringer/Canon MP-E 65mm macro lens

In a recent blog post I mentioned that I was looking forward to testing the Fringer EF-FX Pro II lens mount adapter with my Canon MP-E 65mm Macro lens.

The MP-E 65mm doesn’t have a ring for focusing on the subject — you set the magnification ratio (from 1x to 5x) and move the camera/lens rig back and forth until the subject is in focus. For all photos, I focused on one eye of the model.

Dimetron

The first studio model is a toy Dimetron, photographed at a magnification ratio of 1:1. The toy is ~3.6 cm (~36 mm) long. The size of the APS-C sensor in the Fujifilm X-T3 is 23.5 mm x 15.6 mm. At 1x magnification, the entire length of the toy doesn’t fit on screen.

Dimetron toy | 1:1 magnification | 1/16 flash power ratio

With the camera/lens set for the same f/stop, shutter speed, and ISO (f/5.6, 1/250 s, and 400, respectively), less light reached the sensor when the magnification ratio was increased from 1:1 to 2:1. So I increased the flash power ratio by one stop, from 1/16 power to 1/8 power.

Dimetron toy | 2:1 magnification | 1/8 flash power ratio

Triceratops

The last studio model is a toy Triceratops, photographed at a magnification ratio of 1:1. The toy is ~4.3 cm (~43 mm) long.

Triceratops toy | 1x magnification | 1/16 flash power ratio

As with the first model, when the magnification ratio was increased from 1:1 to 2:1 it was necessary to increase the flash power ratio by one stop.

Triceratops toy | 2x magnification | 1/8 flash power ratio

Gear Talk

The Fringer EF-FX Pro II lens mount adapter enables one to mount Canon lenses on Fujifilm X-Series digital cameras. As you can see, my Canon MP-E 65mm macro lens works well with the Fujifilm X-T3 camera.

The APS-C sensor inside the Fujifilm X-T3 digital camera has a crop factor of 1.5x, so the Canon MP-E 65mm macro lens has a focal length of ~98mm (35mm equivalent) when mounted on an X-T3. The net result is an increase in apparent magnification, …

Post Update Update

Just because something looks like a duck and seems to act like a duck doesn’t mean it’s a duck. And so it is with the Fringer EF-FX Pro II lens mount adapter — although it looks like an extension tube, it isn’t. Why was I deceived by its appearance? Because I didn’t understand something called “flange focal distance.”

For an interchangeable lens camera, the flange focal distance (FFD) … of a lens mount system is the distance from the mounting flange (the interlocking metal rings on the camera and the rear of the lens) to the film or image sensor plane. This value is different for different camera systems. Source Credit: Flange focal distance. Wikipedia.

For example, the FFD for Canon EF-mount is 44 mm and the FFD for Fujifilm X-mount is 17.7 mm. In order to make a Canon EF lens perform properly on a Fujifilm X-series camera body, an adapter must move the Canon lens 26.3 mm farther from the digital sensor. (44 mm – 17.7 mm = 26.3 mm)

Not surprisingly, when I remeasured the thickness of my Fringer EF-FX Pro II lens mount adapter it turns out to be closer to 26 mm than my original course estimate of 30 mm (cited below). The net result is the 17.7 mm FFD of my Fujifilm X-T3 combines with the 26.3 mm thickness of the Fringer adapter, resulting in an FFD of 44 mm — exactly the right FFD for the Canon lens to work properly on a Fujiflm X-series camera body!

It’s worth noting that “apparent magnification” is still a real thing when a camera lens designed for a “full-frame” camera is mounted on a camera with an APS-C size sensor. The image formed by the lens is exactly the same size regardless of the size of the digital sensor used to record the image, but a smaller part of the image is “seen” by an APS-C sensor than a full-frame sensor, resulting in the misperception that the image is magnified.

I hope this sets the record straight. Sincere apologies for any confusion I might have caused — I never heard of “flange focal distance” before I bought the Fringer adapter!

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[Post Update: From this point forward everything I wrote is incorrect. Is my face red, or what? I’ll explain further when I have a chance to use a desktop computer to edit this post.] … although the images appear to be magnified more than can be explained by this fact alone.

In the opinion of this author, the Fringer adapter functions like an extension tube. The adapter is ~3.0 cm (30 mm) in thickness. There aren’t any optics inside the adapter but it does move the lens 30 mm farther from the camera sensor. That, my friends, is an extension tube.

I used an online, interactive Macro Extension Tubes Calculator to estimate the effect of a 30mm extension tube on photos taken with the Canon MP-E 65mm macro lens at magnification ratios of 1:1 and 2:1. The calculator shows the magnification ratio increased from 1:1 to ~1.5:1 and 2:1 to ~2.5:1 respectively.

Macro Extension Tubes Calculator | 1:1 magnification ratio

The values for “new minimum focusing distance” are in millimeters, despite the fact that the second “m” only appears when you click an insertion point in the box and scroll to the right. The values for magnification ratio seem reasonable; the values for new minimum focusing distance, not so much.

Macro Extension Tubes Calculator | 2:1 magnification ratio

[End of segment with information that is incorrect.]

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Related Resources

Full-size photos of the preceding studio models are featured in the following blog posts. Those photos should help to give the reader a better sense of how much the subjects were magnified by the Fujifilm/Fringer/Canon MP-E 65mm macro lens rig.

• What is it? (published on 21 DEC 2020)
• What is it? It’s a toy Dimetrodon. (published on 23 DEC 2020)
• Toy dinosaur: focus-stacked composite image (published on 08 JAN 2021)
• Flange focal distance, by Wikpedia.
• Sensor Size and Magnification – correcting a common misunderstanding, by Allan Walls Photography (20:02). Fast-forward to 5:48. See also Sensor Size Matters – Part 1 (the Front Half) – A Demonstration (19:51).

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