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.

Zerene Stacker DOF Calculator

The DOF Calculator featured in Zerene Stacker is by far the best tool for determining depth of field and the safe step size for focus bracketing. Rik Littlefield, creator of Zerene Stacker, recently released an online interactive version of DoF Calculator. Sincere thanks to Rik for sharing his expertise!

How to use the calculator

There are several ways to use the DOF Calculator, as shown in the following screen capture. I used two methods to calculate the “safe step size” (with 20% overlap) for focus bracketing with all of my basic macro photography rigs.

Choose Option 1 for the best quality focus stacked composite images. Set the aperture for your camera lens to its “sweet spot.”

Screen capture used with permission from Rik Littlefield.

Choose Option 4 if you are using a microscope objective for a macro lens.

As you can see in following examples, it isn’t necessary to input values for every field in the calculator.

AmScope / Reakway 4x microscope objective

Determining depth of field – safe step size for a 4x microscope objective is the simplest calculation of all my macro photography rigs. All you need to input is the “NA” (numerical aperture) that’s labeled on the side of the microscope objective. In this case, the NA equals 0.10.

Photo Credit: AliExpress / Reakway.

It’s recommended that you use a 20% overlap between steps. Input a value of 0.2 in the field for “Step overlap.”

Screen capture used with permission from Rik Littlefield.

DoF: 0.054862 mm (54.862 microns)
Step size (suggested) at 20% overlap: 0.04389 mm (43.89 microns)

Let’s apply the output from the DOF Calculator (shown above) to my relatively new NiSi Macro [manual] Focusing Rail NM-200. The larger adjustment knob is shown below. One full rotation of the knob moves the carriage one millimeter, or 1,000 micrometers (microns). The knob is marked in 100 increments, so each increment on the knob is 10 microns. Every numbered increment is 100 microns.

For my 4x microscope objective, I would turn the adjustment knob four (4) increments between shots or 40 microns (rounded down from 43.89 microns). It’s OK to use a smaller step size than the DOF Calculator recommends.

Photo Credit: B&H Photo.

Laowa 25mm Ultra Macro (at 2.5x, f/4) plus Fujifilm X-T3

The Laowa 25mm Ultra Macro lens can be set for magnifications ranging from 2.5x to 5x. The following example shows the lens set for 2.5x. Input a magnification of 2.5, and a lens F-number of 4 (an aperture of f/4 is the “sweet spot” for this lens).

Screen capture used with permission from Rik Littlefield.

DoF: 0.068854 mm (68.854 microns)
Step size (suggested) at 20% overlap: 0.055083 mm (58.038 microns)

For the Laowa 25mm Ultra Macro lens, I would turn the adjustment knob on my NiSi NM-200 five increments between shots or 50 microns (rounded down from 58.038 microns).

Fujinon 80mm macro (1x, f/8) plus Fujifilm X-T3

The Fujinon 80mm macro lens is one of the sharper lenses I own. Maximum magnification is 1:1 (life size).

Screen capture used with permission from Rik Littlefield.

DoF: 0.56306 mm (~563 microns) ← remember 1 mm = 1,000 microns
Step size (suggested) at 20% overlap: 0.45045 mm (~45 microns)

Each increment on the NiSi NM-200 manual focus rail is equal to 10 microns. For my Fujinon 80mm macro lens, I would turn the adjustment knob four numbered increments between shots — equal to a distance of 40 microns (rounded down from ~45 microns).

Canon 100mm macro (1x, f/11) plus Canon EOS 5D Mark II

The Canon 100mm macro is another one of the sharper lenses I own. Maximum magnification is 1:1 (life size).

Screen capture used with permission from Rik Littlefield.

DoF: 1.0647 mm (1064.7 microns) ← remember 1 mm = 1,000 microns
Step size (suggested) at 20% overlap: 0.85176 mm (851.76 microns)

Each numbered increment on the NiSi NM-200 manual focus rail is equal to 100 microns. For my Canon 100mm macro lens, I would turn the adjustment knob eight numbered increments between shots — equal to a distance of 800 microns (rounded down from 851.76 microns).

Canon MP-E 65mm macro lens (1-5x) plus Canon 5D Mark II

The Canon MP-E 65mm macro lens can be set for magnifications ranging from 1x to 5x. The following example shows the lens set for 3x.

Screen capture used with permission from Rik Littlefield.

DoF: 0.12251 mm (122.51 microns)
Step size (suggested) at 20% overlap: 0.098008 mm (~98 microns)

Remember, each increment on the NiSi NM-200 manual focus rail is equal to 10 microns. For my Canon MP-E 65mm macro lens set for 3x magnification, I would turn the adjustment knob nine increments between shots — equal to a distance of 90 microns (rounded down from ~98 microns).

Related Resource

What if you don’t know the magnification of the macro rig you’re using? Or maybe you add an extension tube and/or close-up filter to a 1x macro lens — how does that change the magnification of the lens?

How to measure magnification provides photo-illustrated step-by-step directions, including sample math calculations.

The Backstory

I have been working behind the scenes trying to figure out how to determine focus bracketing step size for a variety of macro photography gear that I own. I have tested many depth of field – step size calculators and all of them are fatally flawed in one or more ways except for the one in Zerene Stacker.

See How to calculate step size for a long thread of posts related to my search for the answer to what turned out to a more complex process than I imagined. Thanks to the many members of photomacrography.net, especially Rik Littlefield, who kindly and patiently answered all of my questions.

Copyright © 2023 Walter Sanford. All rights reserved.

Manual focus rails: Useful or useless?

For the purpose of this blog post, let’s establish there are two types of focus rails: manual; and automatic. This blog post will focus on manual focus rails only.

Manual focus rails are useful for positioning your camera more easily when it’s mounted on a tripod. But most manual focus rails are essentially useless as an aid for creating macro focus stacked composite images. The issue is lack of precision. More about that later in this post. For now, let’s review a brief history of manual focus rails that I own and have tested.

Neewer

The Neewer Pro 4-Way Macro Focusing Focus Rail is the first focus rail that I bought and is still available for $39.99 from Amazon. Trust me when I tell you this focus rail is anything but “Pro” but the price was right (given what I was willing spend for a focus rail at the time) and turned out to be a relatively inexpensive way to gain experience using a focus rail.

The rulers on each rail are marked in centimeters; the finest increments are in millimeters.

Photo Credit: Amazon.

Novoflex

My next focus rail — the Novoflex Castel-L Focusing Rack — was a significant step up in price. The same model is still available for $279.00 from B&H Photo — overpriced like all products made by Novoflex, in the opinion of this author. This is one of only a few pieces of photography gear that I really regret buying.

Although the focus rail is beautifully engineered and operates smoothly it is no more precise than the much less expensive Neewer focus rail: the ruler on the rail is marked in centimeters; the finest increments are in millimeters.

Photo Credit: B&H Photo.

NiSi

I recently bought a NiSi Macro Focusing Rail NM-200 for $199.95 from B&H Photo. At that price point, the NiSi focus rail is five times more expensive than the Neewer focus rail, and nearly $80 less than the Novoflex focus rail.

Notice the ruler on the rail is still marked in centimeters and millimeters. So why would I waste more money on another focus rail that is no more precise than the other two? Because it turns out it is more precise than the other two!

Photo Credit: B&H Photo.

Look closely at the larger adjustment knob shown below. One full rotation of the knob moves the carriage one millimeter, or 1,000 micrometers (microns). The knob is marked in 100 increments, so each increment on the knob is 10 microns. Now we’re getting somewhere!

Photo Credit: B&H Photo.

Thanks to Andy Astbury for verifying the math using a digital caliper. (As part of my due diligence, I watched Andy’s video before deciding to buy the NiSi NM-200.)

Screen capture from YouTube video by Andy Astbury.

Do you need a focus rail with 10 micron precision?

In a word, yes!

According to Allan Walls, macro photography guru extraordinaire, the following list shows the “safe step sizes” for different macro lenses. Remember, the goal is to move the camera with 30% overlap between steps.

• 1x:1 = 0.7 mm (700 micrometers, a.k.a., microns) ← 70 increments on NiSi NM-200
• 2x:1 = 0.25 mm (250 microns) ← 25 increments on NM-200
• 4x = 0.1 mm (100 microns) ← 10 increments on NM-200

It’s somewhat unclear whether the preceding step sizes include the recommended 30% overlap. In Macro Talk #18, Allan said a step size of 60-70 microns would be better at 4x magnification (6-7 increments on the NiSi NM-200). Another macro photographer recommends a step size of 50 microns at 4x (5 increments on the NM-200). Regardless of which advice you follow, the NiSi NM-200 is capable of getting the job done.

As you can see, even at 1:1 magnification the recommended step size is less than a millimeter. The same idea expressed another way: It’s impossible to use a focus rail marked in one millimeter increments to do macro focus bracketing with right size step between images consistently. That is, unless you find a manual focus rail like the NiSi NM-200 that enables fine adjustments.

Testing 1, 2, 3 …

I just set up my new NiSi focus rail and need to do some testing. I am encouraged by the results achieved by other photographers using the same rail. Stay tuned for a follow-up blog post in the near future.

Related Resources

• Neewer Pro 4-Way Macro Focusing Focus Rail
• Novoflex Castel-L Focusing Rack – with MiniConnect Quick Release
• NiSi Macro Focusing Rail NM-200 with 360° Rotating Clamp (7.9″ Length)
• NiSi NM 200 Macro Focus Stacking Rail Review – Budget Friendly Macro Focus Stacking Accuracy, by Andy Astbury (49:55)
• Nisi NM-200: Best Manual Macro Focusing Rail!? – First Impression, Testing & Tips, by peterviragphoto (8:50)

Copyright © 2023 Walter Sanford. All rights reserved.

George Washington

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

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.

• Fujifilm MCEX-16 [16mm extension tube]
• Fotasy Extension Tube DG 16mm FX
• Fotasy Extension Tube DG 16mm FX
• 3-D printed plastic lens adapter (“crop” configuration)
• Reakway 4x microscope objective

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.

• Get a basic X Mount to M42 adapter like … Fotodiox Lens Mount Adapter Compatible with M42 Screw Mount SLR Lens on Fuji X-Mount Cameras $14.95
• then use M42 tubes to get the required total length, …
• and finally an M42-to-RMS adapter like either … Pixco Lens Adapter Replacement Suit For RMS Royal Microscopy Society Lens to M42 Mount, Caliber:25mm $9.70 [flat] or … RMS Thread for Microscope Objective to M42 x 1 mm Converter Cone Only Adapter $39.99 [cone].

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

• FAQ: How can I hook a microscope objective to my camera? Post by rjlittlefield.
• Rube Goldberg 4-5x macro photography rig, a blog post by Walter Sanford.
• 5x magnification, another blog post by Walter Sanford.
• Have you ever wondered…? A blog post by Walter Sanford, related to focal plane mark.

Copyright © 2022 Walter Sanford. All rights reserved.

Rube Goldberg 2.75x macro photography rig

My Rube Goldberg 4-5x macro photography rig can be configured as both a 2.75x and 4-5x magnification macro photography rig. This blog post will focus on the 2.75x configuration.

The first two photos show the 3-D printed plastic lens adapter with the middle segment removed. A Reakway 4-5x microscope objective is screwed into the front of the adapter and the adapter/”lens” combo is mounted on my Fujifilm X-T3 mirrorless camera.

Photo focused on body of Fujifilm X-T3 mirrorless camera.

Photo focused on Reakway 4-5x microscope objective.

A recent blog post featured handheld test shots using the macro rig configured for 4-5x magnification. One of those shots shows the word “Liberty” on a penny, that is, a 1-cent coin in U.S. currency. Remember, the actual size of the word on the coin is approximately 5 mm in length.

A copper penny photographed at 4-5x magnification.

The same penny was photographed at 2.75x using the “crop” configuration of the lens adapter. The camera was handheld, like the 4-5x test shot shown above. Notice how much more of the coin is visible at 2.75x versus 4-5x magnification.

A copper penny photographed at 2.75x magnification.

The last image is a focus-stacked composite of four photos that were shot with the camera mounted on a tripod.

Focus-stacked composite image of four photos at 2.75 magnification.

What are the take-aways?

I own two macro lenses capable of 1-5x magnification: a Canon MP-E 65mm macro lens; and a Laowa 25mm Ultra Macro lens.

The current retail price of the Canon MP-E 65mm macro lens is $1,049.00. It weighs 1.56 pounds (710 g).

The current retail price of the Laowa 25mm Ultra Macro lens is $399.00. The Laowa macro lens is noticeably smaller and lighter than the Canon MP-E 65mm. It weighs 14.11 ounces (400 g).

The 4x microscope objectives from AmScope and Reakway cost ~$25.00 each. (Remember, you need to buy only one objective.) The weight of the “lenses” isn’t listed in their specifications, but they are relatively lightweight. The 3-D printed plastic lens adapter cost $50.00 including $35.00 for the adapter itself and $15.00 handling and shipping from New Zealand. The plastic adapter feels nearly weightless.

For me, the single biggest take-away is for ~$75 I was able to buy an extreme macro photo rig that takes photos that are as good or better quality than comparable macro lenses that cost hundreds of dollars more!

And as a big fan of lightweight camera gear for use in the field, I’m far more likely to carry one of the Rube Goldberg rigs with me than either of its bigger and heavier counterparts.

Related Resources

• Rube Goldberg 4-5x macro photography rig, a blog post by Walter Sanford.
• 5x magnification, another blog post by Walter Sanford.
• Macro Photography with a $20 Microscope Lens, by Micael Widell (9:37). Micael’s video (and related resources in the show notes) piqued my interest in macro photography using microscope objectives.
• 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.
• Microscope adapter for 4x macro photography, by Sherlock Photography.
• 4X Plan Achromatic Objective Lens with Knurled Ring [AmScope]
• CE, Top quality 4x Plan Microscope achromatic Objective lens, Biological Microscope Lens parts (DIN160/0.1mm) [AliExpress]

Copyright © 2022 Walter Sanford. All rights reserved.

Rube Goldberg 4-5x macro photography rig

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.”

Photo credit: Nicholas Sherlock Photography.

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

• Macro Photography with a $20 Microscope Lens, by Micael Widell (9:37). Micael’s video (and related resources in the show notes) piqued my interest in macro photography using microscope objectives.
• 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.
• Microscope adapter for 4x macro photography, by Sherlock Photography.
• 4X Plan Achromatic Objective Lens with Knurled Ring [AmScope]
• CE, Top quality 4x Plan Microscope achromatic Objective lens, Biological Microscope Lens parts (DIN160/0.1mm) [AliExpress]
• What is the difference among achromatic, semi-plan, and plan objectives? Celestron, LLC.
• What do the numbers on the barrel of the microscope objective mean? What about the letters DIN and JIS? Celestron, LLC.

Copyright © 2022 Walter Sanford. All rights reserved.

How to measure magnification

The magnification of any macro photography rig can be determined by using the rig to photograph a metric ruler such as the one shown below.

Plastic 15 cm (6″) ruler from the Natl. Science Teachers Assn. (NSTA).

The following photograph was 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. Notice that only a tiny part of the ruler is shown in this “full frame” (uncropped) macro photo!

Segment of an NSTA metric ruler.

The formula for magnification is as follows.

length of camera sensor, in mm / #mm visible in photo frame

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

The APS-C digital sensor featured in the Fujifilm X-T3 is 23.5 mm long. The annotated image shows 5.35 mm of the small plastic ruler is visible in the photo frame.

23.5 mm / 5.35 mm = ~4.4x

The actual magnification of the AmScope 4x microscope objective is greater than 4x due to the design of the lens adapter.

What are the take-aways?

As a result of photographing the ruler, subject selection should be easier. Now I know ~5 mm is the size limit for subjects to fit entirely within the photo frame. That’s actionable intel.

Related Resource: How to Calculate Your Camera’s Magnification in Macro Photography, by Stewart Wood (12:02).

Tech Tips

The “Ruler Tool” in Adobe Photoshop was used to measure the length (in pixels) of 5 mm along the double-headed red arrow superimposed on the plastic ruler shown above. That value was used to set a “Custom Scale” for the ruler, in millimeters. (See Setting a Custom Scale and Measuring in Photoshop for more step-by-step instructions.)

Select the “Ruler Tool.” From the Menu bar, select Image / Analysis / Set Measurement Scale. 60s ‘shop: Using the ruler tool to measure distances in Photoshop CC, by Photoshop for the Scientist (1:00) provides a clear and concise explanation of how it’s done.

Then the “Custom Scale” for the “Ruler Tool” was used to measure the entire length along the ruler that’s visible in the photo frame: 5.35 mm.

Post Update

“Photopea” is a free Web-based clone of Adobe Photoshop — Photopea doesn’t do everything Photoshop does but it can be used to measure length (in pixels) using its version of a ruler tool.

Right-click on the “Eyedropper Tool” — located in the left sidebar of the main window — and select the “Ruler Tool.” Click and drag a line segment; record the length of the line, in pixels. Click the “Clear” button (optional) and repeat the same process for more line segments, as needed.

As far as I know, the Photopea “Ruler Tool” doesn’t allow the user to set a custom scale. No problem. Make measurements similar to mine and set up a proportion of two similar ratios.

x mm / 5 mm = #pixels for photo frame / #pixels for 5 mm

Solve for x by cross-multiplying and dividing.

x mm = #pixels for photo frame x 5 mm / #pixels for 5 mm

Remember that similar units above and below the dividing line cancel (pixels, in this case) so the final answer is in millimeters (mm).

Copyright © 2022 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.