Helicon Focus: Rendering in action (plus Post Update)

In my last blog post, I shared a composite image that was created using Helicon Focus to focus stack 99 JPG photos taken automatically using my Fujifilm X-T5 set for AUTO FOCUS BKT.

The following video demonstrates two strengths of Helicon Focus.

1. It’s relatively simple to use. Creating a focus stacked composite image can be as easy as a two-step process: add source images to Helicon Focus by drag-and-drop; click the “Render” button.
2. Rendering works quickly. For example, 99 photos focus stacked in ~50 seconds! (~00:08 s to ~00:58 s.)

The main window features two panels: the panel on the left shows the source images as the focus stack is created; the panel on the right shows the final output.

The right sidebar shows a list of filenames for the source images. When a filename in the list is highlighted, the corresponding image is displayed in the left panel of the main window.

Look closely at the final output, shown in the right panel in the main window. Notice the “ghost” artifact that’s visible near the tip of the toy dinosaur’s tail. Otherwise, the composite image looks perfect.

Click here to see a Screen Recording of the Rendering process.

I have no idea what caused the artifact. For whatever reason, some of the composite images I have created using Helicon Focus have one or more artifacts.

In contrast, every time I have used Fujifilm AUTO FOCUS BKT it has worked perfectly. (He said with fingers crossed.)

Related Resources

• https://youtu.be/jr5SMaO4qWI
• When dinosaurs attack! – This blog post shows the final image after I used Helicon Focus “Retouching” to fix the “ghost” artifact.
• Focus bracketing and focus peaking – When I watched the real-time display of Helicon Focus rendering “Method C” for the first time, I was reminded of a blog post featuring two videos I created to demonstrate how focus peaking can show the way focus bracketing works. Those videos aren’t as steady and smooth as I’d like, but hey, not bad for a manual focus rail!

Post Update

When I tested the link to the video I noticed a problem with “flash dropout.” Two small LED panels and two external flash units were used to light the scene. Notice the flash on the right side of the subject didn’t fire in photo DSCF1214.JPG. That flash was a Godox MF12. Up until now, the MF12 flash has never failed to fire. For those who might be wondering, the Lithium Ion battery in the MF12 was fully charged before I started the focus bracket. I’ll watch it more closely to see whether reliability is an issue.

Copyright © 2023 Walter Sanford. All rights reserved.

When dinosaurs attack!

Run for your life!

Toy dinosaur.

The preceding composite image was created using Helicon Focus to focus stack 99 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.

When you use AUTO FOCUS BKT, you select two endpoints for your focus bracket (Point A and Point B) and the camera sets the step size between shots automatically.

If your goal is to create a composite image with the subject entirely in focus, here’s a helpful tip. As you are looking through the camera viewfinder, or in my case looking at the LCD on the back of the camera, it can be difficult to be sure which point on the subject is closest to the front of the lens and which point is farthest.

For example, looking at the composite image shown above, can you be certain one of the toy dinosaur’s legs doesn’t extend in front of it’s nose? I couldn’t. So what should you do before starting the photo shoot?

I think it’s helpful to look at the subject perpendicular to the camera/lens line of sight, as shown below. In this straightforward example the nearest and farthest points on the subject are obvious — Point A is the tip of the dinosaur’s nose and Point B is the tip of it’s tail. This tip should be useful for subjects that are more complex than my toy dinosaur.

Toy dinosaur (side view).

For what it’s worth, the preceding photograph was taken using my Apple iPad mini 2.

Tech Tips

“Rendering” Method C in Helicon Focus worked best for this subject/composition, but it didn’t work perfectly. There was one artifact that doesn’t appear in any of the 99 focus bracketed photos used to create this composite image, so I knew that in-camera focus bracketing was working properly in my Fujifilm X-T5.

I used “Retouching” to fix the artifact. This was the first time I have used the retouching tools in Helicon Focus. I must admit the experience wasn’t as painful as I was led to believe, but it took a little experimentation to figure out the process.

At this point, I feel like I don’t have enough experience to share directions for how I removed the artifact. But I did take notes so I can refine the process and you can be sure I’ll do a follow-up blog post related to retouching as soon as I don’t feel as lost as I did this this time!

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.

More testing, AUTO FOCUS BKT (plus Post Update)

Someone I know is fond of saying “A sample size of one proves nothing.” And that’s true, at least in the case of my recent test of Fujifilm AUTO FOCUS BKT. So I refined my step-by-step instructions slightly and tested the process again. Two times, in fact. And the results are comparable to my first test.

I have learned from experience it’s better to use a rugged toy “model” for testing purposes, rather than one of the fragile odonate exuviae that I like to photograph. It’s a good idea to choose a test subject that’s about the same size as your intended subject. The following toy dinosaur is ~6 cm from head to tail — the same size as the largest specimen in my collection of exuviae.

Two flashes

The following composite image was created using Helicon Focus to focus stack 74 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 dinosaur plus NSTA plastic ruler.

As you can see, both the toy dinosaur and NSTA plastic ruler are in focus from front-to-back without any focus banding. Zoom in to look at the full-size composite image — the detail is impressive!

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 used rendering Method B in Helicon Focus. Time permitting, I would like to try Method A and Method C to see whether the artifacts go away. The artifacts are visible in both the “Two flashes” and “One flash” versions of the composite image, and upon further review, also visible in the composite image of the toy lizard featured in my last blog post. I must admit this is cause for concern.

Post Update: I used Helicon Focus rendering Method A and Method C to re-render the composite images: Method A was better than Method B; Method C nailed it! For details, please see my blog post entitled “I love it when a plan comes together!“

One flash

The setup for the “one flash” photo shoot was exactly the same as the “two flashes” version except I used one fewer external flash unit.

The following composite image has higher contrast than the first. Although I like the look, I was curious to see how adding a second flash would affect the final result.

Toy dinosaur plus NSTA plastic ruler.

I’m still undecided about which version I like more, but the order in which they are presented in this post provides a big hint. Which version do you prefer — is less more?

Related Resources

• AUTO FOCUS BKT – a blog post by Walter Sanford. Hey, that’s me!
• 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.

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.

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.

Comedy of errors

My first big focus stack turned out to be a comedy of errors. Lots of little things, all of them avoidable, but the one that broke the stack was when the camera battery died approximately two-thirds of the way through the project.

My new Fujifilm X-T5 has a much larger battery than my Fujifilm X-T3 so I never imagined it wouldn’t last long enough to create the stack.

I might have been able to salvage the stack by changing the battery without removing the camera from the focus rail, but the Manfrotto quick release plate partially blocked the battery door. Doh!

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 X-T5 because it’s new enough that the selection of compatible L-brackets is poor.

I have two ways to provide continuous power for the X-T5 but I couldn’t use them because the battery door was partially blocked. Double doh!

Making lemonade from lemons

Long story short I used Helicon Focus to stack all the photos up until the power failure and the results look fairly good, as shown below. Oh what might have been. Triple doh!

ISO 400 | 80mm | 0 ev | f/8 | 1/250 s

The preceding composite image was created from 192 of 328 photos. I used a safe step size of 50 µm (microns) between photos. Each JPG photo is ~13 MB, 7728 × 5152 pixels.

The coin is acceptably in focus from the top of the coin to a point about two-thirds of the way toward the bottom. Zoom in on the horse’s head and you should notice sharp focus is lost beginning below its eye.

The amount of detail in the composite image is astounding, as shown in the close-up of the upper-right quadrant.

Close-up, upper-right quadrant.

Related Resource: Post update on 11 April 2023.

Copyright © 2023 Walter Sanford. All rights reserved.

TJ short stack

Just in time for President’s Day on 20 February 2023, I cooked up a “short stack” composite image of part of a nickel, that is, a five-cent coin in U.S. currency.

The face/head of Thomas Jefferson appears on one side of the nickel. Jefferson was the third president of the United States of America.

Part of a nickel (five-cent coin in U.S. currency).

There are many noticeable scratches on the coin.

The metal nickel has a hardness of 4.0 on Mohs Hardness Scale.

A mineral’s hardness is a measure of its relative resistance to scratching, … Source Credit: Mohs Hardness Scale, National Park Service.

Many minerals/common objects are harder than nickel, such as quartz, glass, and steel, to name a few, and can scratch the coin easily.

Tech Tips

The preceding composite image …

• was created using four photos shot with my Fujifilm X-T3 camera and Laowa 25mm Ultra Macro lens. 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 photos.
• is focus-stacked for greater depth of field. At a magnification of 2.5x the depth of field is extremely shallow. 0.0896 mm (89.6 microns), to be exact.
• is “full frame” (6240 × 4160 pixels), meaning it is uncropped.
• was created using four unedited JPG files, straight out of the camera, that were focus stacked using Adobe Photoshop.

Related Resources

• GW revisited [George Washington, first president of the United States of America.]
• Trust [Abraham Lincoln, 16th president of the United States of America.]
• One thin dime [Dwight D. Eisenhower, 34th president of the United States of America.]

Copyright © 2023 Walter Sanford. All rights reserved.

Proof of concept: NiSi NM-200 manual focus rail (plus Post Update)

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 µm (micrometers, also known as 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. [See Post Update, at the end of this blog post.] 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

Post Update

In the preceding post I wrote “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.”

Well, someone with more experience than me in creating focus stacked composite images actually looked closely at my image, and here’s what he saw.

Annotated image used with permission from Rik Littlefield.

Rik Littlefield, creator of Zerene Stacker, noticed there is in fact a problem with focus banding in my composite image. Rik highlighted the focus bands with a series of black dots.

My decision to use a “safe step size” of 200 microns was based upon the output from a depth of field – step size calculator that I now realize is fatally flawed. Honestly I can’t remember which calculator I used, but I can tell you this — after using Rik Littlefield’s DOF Calculator to determine the safe step size for the same macro rig is 58.038 microns, I knew 200 microns must not have worked as well as I thought. And as you can see in Rik’s annotated image, a step size of 200 microns is too big. Sincere thanks to Rik for his feedback!

Copyright © 2023 Walter Sanford. All rights reserved.

Dromogomphus spinosus exuvia (ventral view)

A dragonfly exuvia was collected by Joe Johnston on 22 May 2019 at Aquia Creek, Stafford County, Virginia USA. This specimen is the cast skin from a Black-shouldered Spinyleg (Dromogomphus spinosus) larva (nymph). D. spinosus is a member of Family Gomphidae (Clubtails).

The specimen is approximately 3.3 cm (~1.3 in) long, measured from head to tail.

15 FEB 2021 | BoG Photo Studio | D. spinosus exuvia (ventral)

Male odonates 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).

This male specimen has too much dirt on S9 to see the primary genitalia; the secondary genitalia are visible on S2-3. I plan to annotate the image in order to highlight select anatomical features.

Related Resources

• Dromogomphus spinosus exuvia [dorsal view]
• Odonate Exuviae – a hyperlinked list of identification guides to many species of odonate exuviae from seven families of dragonflies and three families of damselflies.
• Sexing odonate exuviae (Anisoptera)

Tech Tips

The subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. The exposure was increased by 0.3 stop during post-processing in order to attain a pure white background.

A composite image was created from several photos taken using a Fujifilm X-T3 digital camera, Fujifilm MCEX-11 extension tube, Fujinon XF80mm macro lens, and an array of external lights.

One external flash unit was used to create the white background and two others to light the subject. A Sunpack LED 160 was used as a focusing aid.

RAW FILE CONVERTER EX 3.0 was used to convert six (6) RAW (RAF) files to TIFF files. In a departure from my usual workflow, the TIFF files were loaded into Adobe Photoshop CC 2017 in order to create the focus stacked composite image. The composite image was edited using Apple Aperture and sharpened using Photoshop.

Tech Take-aways

Notice there is some color fringing (mostly reds) that is especially noticeable on the front legs and antennae, as well as along the edges of the posterior abdomen. I have been experimenting with a new technique for backlighting the subject. It appears I need to add another layer of diffusion between the light source and the subject.

There is also some “softness” along the edges of the abdomen that could be the result of too few focus points for the shape of the body, which in turn, could have caused artifacts in the composite image.

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