Proof of concept: NiSi NM-200 manual focus rail

The following focus stacked composite image was created using a Fujifilm X-T3 mirrorless digital camera and Laowa 25mm Ultra Macro lens mounted on a NiSi NM-200 manual focus rail.

Toy dinosaur at 2.5x magnification.

The Laowa lens was set for 2.5x magnification and an aperture of f/4, the “sweet spot” for that lens.

The subject is a small toy dinosaur, viewed from above the anterior end of the dino. The toy is approximately 3.2 cm long (~32 mm).

The carriage of the focus rail was moved 200 micrometers (microns) per step, equal to 20 increments on the NiSi NM-200. A total of 28 photos were taken. A little back of the envelope math shows the carriage moved a total of 5.6 mm from beginning to end.

200 microns x 28 = 5,600 microns

5,600 microns x 1 mm/1,000 microns = 5.6 mm

The camera was set to record JPG plus RAF files. For simplicity the composite image was focus stacked in Adobe Photoshop using the JPG files straight out of the camera. The final output was slightly cropped and sharpened.

Look closely at the full size version of the composite image. I don’t see any glaring “focus banding” so the 200 micron step size seems to have worked. As always, a sample size of one proves nothing. That said, I feel confident the NiSi NM-200 works as expected and will be a useful aid for creating macro focus stacked composite images.

Tech Tips

i used a step size of 200 microns — much larger than the 10 micron precision limit of the NiSi NM-200. My goal was to choose the largest step size that wouldn’t show “focus banding.” I’m not sure what the maximum “safe step size” is, given the settings for my photo gear, but it appears 200 microns doesn’t exceed that value.

Related Resource: “Toy dinosaur” includes a photo (shown below) that shows the entire toy. 2.5x magnification is more than it seems!

08 DEC 2020 |  BoG Photo Studio | toy dinosaur

Copyright © 2023 Walter Sanford. All rights reserved.

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.

Dragonfly Curriculum Guide Supplemental Videos

One of my photos is featured in a new video entitled Determining Dragonfly Sex: Dragonfly video 15, by Dr. Ami Thompson. See the inset photo in the following video screen capture.

Determining Dragonfly Sex: Dragonfly video 15, by Ami Thompson.

The video is one of 15 Dragonfly Curriculum Guide Supplemental Videos coproduced by Ami Thompson and Peter Xyooj. The Dragonfly Curriculum Guide (PDF) is available for free.

Notice my last name is misspelled in the credits at the end of the video: Stanford is an institution; I should be institutionalized. <Rim shot!> Oh well, at least my name is spelled correctly in the video screen capture shown above.

Determining Dragonfly Sex: Dragonfly video 15, by Ami Thompson.

The inset photo is from “Mocha Emerald dragonfly claspers,” a blog post that I published on 13 July 2017.

09 JUL 2017 | Huntley Meadows Park | Mocha Emerald (male)

Related Resources

• Dragonfly Curriculum Guide Supplemental Videos, coproduced by Ami Thompson and Peter Xyooj.
• Dragonfly Curriculum Guide (PDF), by Ami Thompson.
• Mocha Emerald dragonfly claspers, a blog post by Walter Sanford.

Copyright © 2022 Walter Sanford. All rights reserved.

Common Green Darner exuviae (male vestigial genitalia)

Male odonates in Suborder Anisoptera (Dragonflies) have two sets of sex organs: primary genitalia located on abdominal segment nine (S9); and secondary genitalia located on abdominal segments two-to-three (S2-3).

For some (but not all) species of odonate larvae/exuviae, sex is indicated by either a rudimentary ovipositor (female) or vestigial genitalia (male). These sex organs don’t look exactly the same for all species of dragonflies, but their function is identical.

The following annotated images show the male vestigial genitalia for two Common Green Darner (Anax junius) exuviae collected by Jason Avery during Summer 2022 in Calvert County, Maryland USA. All of the images show the ventral side of the exuviae.

Male No. 1

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Male No. 2

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Look closely at the following image and you should notice the secondary genitalia appear to extend from S2 to S3. In this case, only the more prominent parts on S3 are labeled.

Summer 2022 | Common Green Darner (Anax junius) | exuvia (male)

Related Resources

• Related post by Jason Avery in Maryland Odonata Facebook group
• Sexing odonate exuviae (Anisoptera)
• Sexing odonate exuviae (Zygoptera)

Tech Tips

All of the preceding images were photographed by Jason Avery and annotated by Walter Sanford. Thanks to Jason for kindly sharing his photos!

Copyright © 2022 Walter Sanford. All rights reserved.

Post update: Which family is it?

The following odonate exuvia is from a damselfly in Suborder Zygoptera.

The overall shape of the prementum (highlighted by a red rectangle) indicates this specimen is from Family Calopterygidae (Broad-winged Damselflies). Notice the embedded raindrop shape (highlighted by a purple rectangle), located toward the upper-center of the prementum — a key field mark for this family.

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

Two genera from Family Calopterygidae are common in the Commonwealth of Virginia: Hetaerina; and Calopteryx. For species in Genus Calopteryx the raindrop shape (Fig. 19) looks more like a diamond shape (Fig. 18), so it’s probably safe to infer this specimen is a species in Genus Hetaerina.

Identification Manual for the Damselfly Nymphs of Florida, p. 13

Related Resources

• Which family is it? – a blog post by Walter Sanford
• Identification Manual for the Damselfly Nymphs (Zygoptera) of Florida, by Johnny S. Richardson

Post Update: Congratulations to Doug Mills, Wally Jones, and Bob Perkins for correctly identifying the family of this exuvia.

Doug and Wally looked at the shape of the prementum. Bob looked at the antennae.

The long middle segment on the antennae is the key, found only on Calopterygidae nymphs. Nymphs of the other families have antenna segments that are progressively shorter from base to tip. Source Credit: Bob Perkins.

Looking at the prementum should enable you to identify all three families; looking at antennae works for only one family.

Copyright © 2022 Walter Sanford. All rights reserved.

Which family is it?

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 | (exuvia, ventral 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 | (exuvia, ventral 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)

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 America: Archilestes 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

• How to Identify Damselfly Exuviae to Family, by Walter Sanford
• A Beginners’ Guide to Identifying the Exuviae of Wisconsin Odonata to Family, by Freda van den Broek and Walter Sanford.
• Sexing odonate exuviae (Zygoptera), by Walter Sanford

Copyright © 2022 Walter Sanford. All rights reserved.

How to find stuff in my blog

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

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.

Depth of Field Calculator

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

• How to use the Post Focus / Focus Stacking feature. [An article from Panasonic.]
• Experience 4K Post Focus in Panasonic LUMIX Cameras – Presented by LUMIX Luminary Photo Joseph, by Panasonic North America (4:33)
• Panasonic FZ80/82 Digital Zoom, 4K Post Focus and Manual Focus, by Graham Houghton (15:16) [The segment related to “Post Focus” begins at ~8:22.]

Copyright © 2022 Walter Sanford. All rights reserved.

Focus bracketing using Panasonic “Post Focus”

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).