Archive for the ‘macro photography using 4x microscope objective’ Category

Focus rails: Useful or useless?

January 17, 2023

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

Copyright © 2023 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.

Rube Goldberg 2.75x macro photography rig

October 28, 2022

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

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.

How to measure magnification

October 18, 2022

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 23.6 mm long. The annotated image shows 5.35 mm of the small plastic ruler is visible in the photo frame.

23.6 mm / 5.35 mm = 4.41x

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.

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

October 14, 2022

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.


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