Posts Tagged ‘focus stacking’

Dromogomphus spinosus exuvia (ventral view)

February 16, 2021

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

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.

Copyright © 2021 Walter Sanford. All rights reserved.

MWAA jet airplane pencil eraser

February 12, 2021

The Metropolitan Washington Airports Authority (MWAA) was the school-business partner with Carl Sandburg Middle School (Fairfax County Public Schools) when I worked at the school as a full-time planetarium teacher and later as a part-time planetarium teacher/part-time physical science teacher.

MWAA always brought good SWAG when they participated in school events like the annual “Career Day.” The jet airplane pencil eraser, shown below, was one of the more popular items.

Single image

An MWAA jet airplane pencil eraser was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. The exposure was increased slightly during post-processing in order to attain a pure white background.

08 FEB 2021 | BoG Photo Studio | MWAA jet airplane pencil eraser

Composite image

The following 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 another to light the subject. A Sunpack LED 160 was used as a focusing aid.

Seven (7) photos were edited using Apple Aperture, exported as TIFF files, then loaded into Adobe Photoshop CC 2017 in order to create the focus stacked composite image.

08 FEB 2021 | BoG Photo Studio | MWAA jet airplane pencil eraser

Look closely at the pencil shaft and you will notice some serious artifacts from the focus stacking process; more serious artifacts were cropped from the top of the image. Hey, sometimes focus stacking using Photoshop works; sometimes it doesn’t. When it works, it works well; when it doesn’t, well, there are artifacts in the composite image. I have read it’s possible to repair those artifacts, but I’ve never had any luck with that.

Copyright © 2021 Walter Sanford. All rights reserved.

When is a yellow pencil not yellow?

February 9, 2021

A yellow pencil isn’t yellow when the subject is photographed in a studio under artificial light and the photographer is more focused on focus than color fidelity.

08 FEB 2021 | BoG Photo Studio | SANFORD EAGLE yellow pencil

I know what you’re thinking. “Gee, I wish I had a pencil with my last name on it.” But you don’t. Hah! This isn’t one of those cheesy pencils you can order with your name on it — oh no, this “Sanford” brand pencil was manufactured by Newell Brands, a public company headquartered in Atlanta, Georgia. Newell Brands also makes “Sharpie” markers.

Tech Tips

A SANFORD EAGLE yellow pencil was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. The exposure was increased by 0.2 stop during post-processing in order to attain a pure white background.

The composite image featured in this blog post 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 another to light the subject. A Sunpack LED 160 was used as a focusing aid.

Six (6) photos were edited using Apple Aperture, exported as TIFF files, then loaded into Adobe Photoshop CC 2017 in order to create the focus stacked composite image.

Announcement: New schedule for publishing blog posts

Beginning on Tuesday, 09 February 2021 blog posts will be published on Tuesday and Friday every week.

I want the followers of my blog to know I struggled with this decision. My decision is based in part on the impact of the pandemic on my day-to-day activities. I’m not sure, but I think this is the first time I’ve mentioned COVID-19 in my blog — I always looked at my blog as a sanctuary from the pandemic for my readers and me. So I soldiered on. That said, with no end in sight for the foreseeable future I must admit I’m started to feel drained and just don’t have the energy to post three times a week.

Going forward, this change might be permanent, at least for the winter months of December, January, and February.

Copyright © 2021 Walter Sanford. All rights reserved.

Toy dinosaur: focus-stacked composite image

January 8, 2021

The following toy dinosaur was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. The toy is 2.96 cm long.

11 photographs were taken using a Fujifilm X-T3 digital camera, Fujifilm MCEX-11 extension tube, and Fujinon XF80mm macro lens. A single focus point was moved to 11 places on the toy.

The photos were edited using Apple Aperture, exported as TIFF files, then loaded into Adobe Photoshop CC 2017 in order to create the focus stack.

07 JAN 2021 | BoG Photo Studio | toy dinosaur

It’s been a while since I created a focus-stacked composite image. All I can say is it’s a good thing I keep good notes related to the experimentation that I do in my “photo studio,” because I had forgotten many of the steps in the workflow!

Copyright © 2021 Walter Sanford. All rights reserved.

Swift River Cruiser exuvia (face-head)

November 20, 2020

The following image is a focus-stacked composite of three photos, focused on the left eye, right eye, and both eyes respectively.

27 May 2017 | Riverbend Park | Swift River Cruiser (exuvia, face-head)

Tech Tips

The dragonfly exuvia was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

Several photos were taken using my Canon EOS 5D Mark II digital camera, a Kenko 12mm extension tube, and Laowa 25mm Ultra Macro Lens, set for f/4.0 (the sweet spot for this lens) at ~3.0x magnification.

Godox TT685C external flash was used to backlight the background (a piece of translucent white plastic) and a Godox TT685F external flash was used as a key light on the right side of the subject. The flash was triggered wirelessly by a Godox X2TC.

Check the EXIF/IPTC info for the photograph for complete details regarding photo gear and camera settings.

Adobe Photoshop CC 2017 was used to create a focus-stacked composite image that was edited using Apple Aperture.

The Backstory

Swift River Cruiser dragonfly (Macromia illinoiensisexuvia was collected on 27 May 2017 along the Potomac River at Riverbend Park in Fairfax County, Virginia USA. This individual is a female.

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Hits and misses

May 25, 2020

This blog post might have been called “New ways of doing the same old thing.” In other words, experimenting with new techniques for shooting sets of macro photos of a familiar  subject and new variations for creating focus-stacked composite images.

80mm (120mm, 35mm equivalent) | f/16 | 1/200s | ISO 160 | 0 ev

Tech Tips

In-camera focus bracketing was used to shoot a photo set with my Fujifilm X-T3 mirrorless digital camera and Fujinon 80mm macro lens (coupled with 11mm and 16mm extension tubes for a little additional magnification).

The camera lens was focused manually on the closest point on the face of the subject. The shutter button was pressed one time; the first photo was taken after a 10-second timer elapsed, then the focus point advanced automatically from the initial focus point to a far point on the subject in the background of the photo.

RAW FILE CONVERTER EX 3.0 was used to batch-convert the resulting 50 images from Fujifilm RAF files to TIFF files. Adobe Photoshop CC 2017 was used to create five sub-stacks (10 photos per sub-stack) that were combined into one focus-stacked composite image. The final image was edited using Apple Aperture.

Analyzing the results

Most of the “misses” were self-inflicted.

For example, minimal effort was invested in arranging the subject and lighting the scene. Generally speaking, better lighting results in better photos.

Some trial and error is required in order to determine the correct focus bracketing settings for a given combination of camera and lens. The following settings were used to shoot the photo set for the focus-stacked composite image featured in this post: Frames = 50; Step = 10; Interval = 4 s.

Step size is a number from one (1) to 10, with one being the smallest increment and 10 being the largest. Although a step size of 10 enabled the camera to cover the subject completely from front-to-back in 50 frames, selecting the coarsest step increment might have resulted in small “focus gaps” that are noticeable in a few places on the full-size version of the composite image.

I cabled a Godox PROPAC PB960 to the Godox TT685C external flash unit that is used to backlight the white background. The power pack enables faster flash recycle times and increases the number of times the flash can be fired before its AA batteries run down. That was a big “hit!”

I didn’t realize the radio flash trigger was set for a power ratio of 1/4 +0.7 — that’s 2/3 of a stop slower than my preferred setting of 1/2 +0.3 that usually results in the pure white background (255, 255, 255) that is a goal of the “Meet Your Neighbours” (MYN) technique. That was a big “miss” I was able to correct in post-processing, although increasing the exposure enough to blow out the background might have degraded image quality a little.

One of many reasons the Fujifilm X-Series cameras are so popular is their retro look and feel, including lots of buttons and dials on the camera body. That’s good and bad: it’s good to be able to adjust many camera settings using either an external button or dial rather than navigating through menus in the camera’s firmware; it’s bad that it’s easy to change camera settings accidentally.

I must have rotated the back dial slightly because the shutter speed was set for 1/200 s rather than the camera sync speed of 1/250 s. Using a faster shutter speed can result in sharper images.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

Macromia illinoiensis exuvia (face-head) redux

May 22, 2020

A Swift River Cruiser dragonfly (Macromia illinoiensis) exuvia was collected, with permission from park staff, on 27 May 2017 along the Potomac River at Riverbend Park in Fairfax County, Virginia USA.

The preceding image shows the remnant ommatidia clearly.

From this viewpoint, it’s harder to see the prominent horn on the face that is a key field mark for larvae/exuviae in the Family Macromiidae (Cruisers). The base of the triangular horn is located above the labium (face mask), between the long, thin antennae; the apex of the triangle is pointed toward the viewer.

It’s easier to see the horn in the featured photo in my last blog post.

Tech Tips

The subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

20 photos of the specimen were taken using 2.5x magnification at an aperture of f/4; in-camera focus peaking was used to highlight select areas in each photo. RAW FILE CONVERTER EX 3.0 was used to convert Fujifilm RAF files to TIFF files. Adobe Photoshop CC 2017 was used to create a focus-stacked composite image that was edited using Apple Aperture.

Copyright © 2020 Walter Sanford. All rights reserved.

Macromia illinoiensis exuvia (face-head)

May 20, 2020

The following photograph of a Swift River Cruiser dragonfly (Macromia illinoiensis) exuvia shows a prominent horn on the face that is a key field mark for larvae/exuviae in the Family Macromiidae (Cruisers).

The specimen was collected, with permission from park staff, on 27 May 2017 along the Potomac River at Riverbend Park in Fairfax County, Virginia USA.

Tech Tips

The subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique. The specimen was posed on its dorsal side, so the camera was focused on the face-head-ventral view of the exuvia. The final image was cropped and rotated 180° during post-processing.

10 photos of the specimen were taken using an aperture of f/16; in-camera focus peaking was used to highlight select areas in each photo. RAW FILE CONVERTER EX 3.0 was used to convert Fujifilm RAF files to TIFF files. Adobe Photoshop CC 2017 was used to create a focus-stacked composite image that was edited using Apple Aperture.

Editor’s Note: This blog post is the last installment in what turned out to be a three-part series. The featured focus-stacked composite image is a little closer to what I had in mind when I set up the photo shoot.

  1. MYN – Macromiidae larvae/exuviae are horny
  2. RAW FILE CONVERTER EX 3.0

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Focus Stacking using Adobe Photoshop

April 1, 2020

The following tutorial provides step-by-step instructions that can be used to create focus-stacked composite images with Adobe Photoshop (Ps).

First, download (from Google Drive) the two 16-bit TIFF files that will be focus-stacked. One photo is focused on the thorax, near the left eye; the other photo is focused on abdominal segment eight (S8).

Save the files to a folder on the desktop of your computer.

Open Photoshop.

  1. File / Scripts / Load Files into Stack… [Navigate to the folder on your desktop and select both files. By default, Ps creates a new document called “Untitled1.”]
  2. Select all layers. [Click on filenames, not icons.]
  3. Edit / Auto-Align Layers; Auto <OK>
  4. Edit / Auto-Blend Layers; Stack Images, Seamless Tones and Colors <OK>
  5. Duplicate layers to a new document. Layer / Duplicate Layers… / Document: New / Name: Backup-copy]
  6. Select “Untitled1”: Layer / Merge Layers (Ps merges all layers into one TIFF, named after the first file in sequence.)
  7. Straighten and Crop as necessary.
  8. Duplicate layer; append name with “Spot Healing.” [Remove dust spots, etc. from image using either Spot Healing Brush (Content-Aware) or Edit/Fill (Content Aware).
  9. “Sharpen” image. Duplicate top layer; append name with “HPF.” [Select top layer: Filter / Other / High Pass…; adjust until you can just see outline of image <OK>; change Normal to Overlay. 1.5 is a good starting point; decrease/increase as necessary. DO NOT OVERSHARPEN!
  10. File / Save As… TIFF; JPG.
  11. Select “Backup-copy.” File / Save As… Photoshop.

The composite image that you created should look like this, not including the copyright information shown in the lower-left corner of my image.

Take-aways

A two-photo focus stack works in part because the photos were shot using an aperture of f/16. Usually more than two “layers” are required to create a satisfactory focus-stacked composite image.

The same workflow can be used to create focus stacks using more layers with one caveat: more layers take more time for Photoshop to process.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Tramea sp. exuvia (ventral)

February 3, 2020

An odonate exuvia, collected by Andy Davidson near Richmond, Virginia USA, was photographed against a pure white background using the “Meet Your Neighbours” (MYN) technique. Two photos were used to create a composite image: one photo focused on the prementum; and another photo focused on abdominal segment eight (S8).

This individual is from the Genus Tramea (Saddlebags), in the Family Libellulidae (Skimmers). Since it’s nearly impossible to differentiate exuviae from the Genus Tramea to the species level, we’ll leave its identity as Tramea sp. It’s the same specimen featured in my last three blog posts: MYN – Tramea sp. exuvia (face-head-dorsal)MYN – Tramea sp. exuvia (dorsal); MYN – Tramea sp. exuvia (dorsal-lateral).

Tech Tips

The subject was photographed against a pure white background using the “Meet Your Neighbours” (MYN) technique. The exuvia was “staged” on a clear plastic surface raised ~1.5 in (~3.81 cm) above the white background.

The dorsal side of the specimen was lying on the clear plastic. The “eyes” were closer to the light source than all other photos/composite images in a four-part series of this subject; as a result, the eyes look washed out. I know from experience that problem can be solved by moving the clear plastic stage farther from the white background.

In this case, I was less concerned about showing the eyes in their best light and more concerned about looking for signs of sex organs that indicate gender. I don’t see anything that looks like either vestigial genitalia (male) or a rudimentary ovipositor (female).

Copyright © 2020 Walter Sanford. All rights reserved.


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