Posts Tagged ‘focus stacking’

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.

MYN – Tramea sp. exuvia (dorsal-lateral)

January 31, 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 thorax, near the left eye; 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 two blog posts: MYN – Tramea sp. exuvia (face-head-dorsal); MYN – Tramea sp. exuvia (dorsal).

What are the take-aways?

I have been wondering whether the MYN technique could be used to create focus-stacked composite images. Wonder no more — it works and the results are worth the extra effort.

Copyright © 2020 Walter Sanford. All rights reserved.

Godox XProF – TCM Function

November 6, 2019

Godox makes two types of wireless flash triggers (radio) that are compatible with Fujifilm X Series digital cameras, listed from less expensive to more expensive: the Godox X2TF; and the Godox XProF. Both flash triggers have essentially the same functions. The X2TF has a slightly lower price point than the XProF, smaller footprint, and a pass-through hot-shoe; it lacks the TCM Function featured on the XProF.

TTL

“TTL” stands for “Through The Lens” metering. Some external flash units, such as the Godox TT685F Thinklite TTL Flash for Fujifilm Cameras, are TTL-compatible, meaning the camera will set the flash power ratio automatically for proper exposure. So what’s not to like about that?

A photographer has no way of knowing what the flash power setting is when using an external flash unit in TTL mode. Some photographers might be surprised to learn that TTL exposure can vary from one shot to another, often quite noticeably. That can be a problem. For example, repeatability is a big concern in macro photography, especially when creating focus stacks. So what’s the solution? TCM Function.

TCM Function

“TCM Function” is a proprietary feature of the Godox XProF that stands for “TTL Converted to Manual,” translated loosely. Here’s how it works.

The “Magnification/TCM Button” (shown below) is a toggle switch: a short-press switches the display on the LCD panel back-and-forth from the settings for all off-camera flash groups (A-E) to a magnified view of the settings for one group, e.g., Group A (that can include one or more external flash units); a long-press activates the TCM Function.

Godox XProF Instruction Manual.

Set the XProF for TTL mode. Take a test shot, then long-press the TCM button. You should see the display on the XProF switch from TTL mode to Manual mode, showing the equivalent manual settings for the TTL test shot.

Godox XProF Instruction Manual.

This feature can be useful for quickly determining a good starting point for setting external flash units in Manual mode. Try it. I think you’ll like it!

Take-aways

Which model Godox radio flash trigger should you buy, the X2TF or the XProF? That depends upon what’s more important to you — either the pass-through hot shoe or TCM Function. You can have one feature or the other but you can’t have both in a single flash trigger.

Related Resource: PIXAPRO ST-IV Functions and Features (Instructional Video), by PIXAPRO (6:59). Note: Godox is known as PIXAPRO in the United Kingdom.

Copyright © 2019 Walter Sanford. All rights reserved.

“Post Focus” image: toy dinosaur

February 8, 2019

A toy dinosaur was “photographed” at BoG Photo Studio using my new Panasonic Lumix DMC-FZ300 digital camera set for “Post Focus.”

The camera was set for ISO 100 and Aperture Priority at f/2.8. Two Sunpak LED-160 Video Lights plus a Nissin i40 external flash unit (set for video light) were used to light the scene. 30 individual frames were extracted from the resulting MP4 video, and saved as TIF files; Adobe Photoshop was used to create the following focus-stacked composite image.

A plastic toy dinosaur.

Noise (graininess) has been a problem in some previous test shots using “Post Focus,” due to low light (underexposure). I changed the ISO from AUTO to 100 for this test, opened the aperture all the way to f/2.8, and added a third LED light source.

This is the first time I tested “Post Focus” and felt like the camera had a mind of its own! Nonetheless, the final output turned out OK. Further research and experimentation is required in order to understand what happened and why.

Copyright © 2019 Walter Sanford. All rights reserved.

“Post Focus” images: Shadow Darner dragonfly

January 30, 2019

Bob Perkins collected and reared a Shadow Darner dragonfly (Aeshna umbrosa) larva/nymph. This blog post features two focus-stacked composite images of a beautifully preserved specimen of the adult that emerged from the larva.

Each composite image was created from 30 TIF files extracted from a one-second MP4 video of the subject, “photographed” using my new Panasonic Lumix DMC-FZ300 digital camera set for “Post Focus.”

This individual is a male, as indicated by his terminal appendages and “indented” hind wings (shown above). All male dragonflies have three terminal appendages, collectively called “claspers”: the two cerci are missing (they broke off the terminal end of the abdomen during shipping); the epiproct is intact.

Shadow Darner (Aeshna umbrosa) | dorsal-lateral view

Takeaways

Perhaps the biggest takeaway from on-going experimentation with Panasonic “Post Focus” is that the process continues to impress — it works quickly (typically one second or so) and works well, using lightweight, inexpensive equipment for making composite images of acceptable quality.

What’s not to like? The obvious answer: The image quality isn’t as high as comparable images created using HEAVY and EXPENSIVE camera gear in the controlled environment of a photo studio. On the other hand, I know from experience I’m unlikely to lug all of that gear into the field. I call it a BIG WIN to have found a relatively lightweight, inexpensive camera kit that does essentially the same job almost as well!

The next test: Use adult dragonflies in the wild as the subject. Regrettably, that will have to wait until the first odonates begin emerging during early spring.

Related Resources

Tech Tips

The following equipment was used to shoot the “photos” for creation of the composite images, shown above: Panasonic Lumix DMC-FZ300 digital camera set for “Post Focus“; and two Sunpak LED-160 Video Lights.

Adobe Photoshop CC 2017 was used to create the preceding focus-stacked composite images, as well as spot-heal and sharpen the final output.

Copyright © 2019 Walter Sanford. All rights reserved.

More testing: Panasonic “Post Focus”

January 28, 2019

A toy dragonfly was “photographed” at BoG Photo Studio using my new Panasonic Lumix DMC-FZ300 digital camera set for “Post Focus.” Two Sunpak LED-160 Video Lights were used to light the scene. 30 individual frames were extracted from the resulting MP4 video, and saved as TIF files; Adobe Photoshop was used to create the following focus-stacked composite image.

A plastic toy dragonfly.

The test shots featured in my last blog post, and this one, were taken in order to establish the proof of concept that Panasonic “Post Focus” can be used to quickly (well, everything is relative) create high quality focus-stacked composite images. After limited testing, I can say the process works fairly well.

The next test: Use a preserved specimen of a real adult dragonfly as the subject. Please stay tuned for my next blog post.

Copyright © 2019 Walter Sanford. All rights reserved.


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