Latest focus stacking workflow

I shot a small set of photos for a focus stack showing the ventral view of an unknown species of odonate exuvia. There are five “slices,” focused from head-to-tail along the body only (no shots focused on legs/feet).

The following gallery shows the five focus points along the body of the specimen, highlighted by a red square.

Focus on mid-body.

Focus on head.

Focus on tail (S9).

Focus between tail and mid-body.

Focus on base of prementum.

Although this photo set has fewer “slices” than I have been using to create focus stacks recently (~15-20 photos, on average), the resulting composite image (shown below) is perfectly in focus along the entire body and is serviceable for the purpose of identifying the genus and species of this specimen.

07 June 2018 | Amherst County, VA | exuvia (ventral)

The preceding composite image shows an exuvia from an unknown species of dragonfly (possibly River Cruiser sp.), collected by Mike Boatwright on 07 June 2018 at Otter Lake in Amherst County, Virginia USA. This individual probably is a male, as indicated by vestigial hamules located on the underside of abdominal segments two and three (S2-3).

Shooting the Photo Set

• Set the camera for Manual Mode.
• Set the lens for manual focus and turn off image stabilization (when the camera/lens is mounted on a tripod).
• Compose the image so the frame is a little bigger than the scene you really want. This will give you some wiggle room during post-processing.
• Set external flash(es) for Manual Mode. (~1/16 power is a good starting point.)
• Select single focus point; move focus point around image.
• Live View plus 5x and 10x magnification.
• Drive mode: 10s timer.
• DON’T MOVE THE CAMERA. Shoot as many images as necessary.

Advance Preparation – Edit Photos Using Aperture [or Lightroom]

Although Apple discontinued development of/support for Aperture years ago, the desktop application still works and in many ways I prefer Aperture over Adobe Lightroom.

• Edit one image: make all adjustments except spot and patch, vignette, and BFX.
• Right-click on edited photo; select “Lift Adjustments.”
• <Replace> <Stamp Selected Images>
• Add metadata: Lift and Stamp selected images.
• Select images (to be focus stacked); export as TIFFs (16-bit), 300 dpi; save in folder entitled either “TIFF” or “TIFF versions.” File / Export… / Version… [Export Preset: TIFF – Original Size (16-bit)]

Focus Stacking Using Adobe Photoshop

Launch Photoshop.

• File / Scripts / Load Files into Stack… [Alternate option: Add Open Files <OK>] Do not check the box for “Create Smart Object after Loading Layers.” By default, Ps creates a new document called “Untitled1.”
• Select all layers.
• Edit / Auto-Align Layers; Auto <OK>
• Edit / Auto-Blend Layers; Stack Images, Seamless Tones and Colors <OK>
• Duplicate all masked layers to a new document. Layer / Duplicate Layers… / Document: New / Name: Backup-copy
• Select Untitled1: Layer / Merge Layers. (Ps merges all layers into one TIFF, named after first file in sequence.)
• Straighten and Crop as necessary.
• Duplicate the layer; append name with “Spot Healing.” [Alternate option: drag layer to copy icon]
• Remove dust spots from the image: Spot Healing Brush: 27-54 pixels, Content-Aware.
• Duplicate the layer; append name with “HPF.” [Alternate option: drag Spot Healing layer to copy icon]
• Select the top layer: Filter / Other / High Pass…; adjust until you can just see outline of image <OK>; change Normal to Overlay. [Don’t oversharpen! ~2.6 used for the composite image featured in this blog post.]
• Untitled1: Save As… TIFF.
• Backup-copy (of masked layers): Save As… either PSD or Large Document Format (for documents larger than 2 GB).
• Import composite TIFF file [Untitled1.tif] into Aperture [or Lightroom]: add additional keywords, as appropriate [e.g., annotated, composite image, focus stack, Photoshop]; Export using BorderBFX.

Tech Tips

The following equipment was used to shoot the composite image (shown above): Canon EOS 5D Mark II digital camera, in manual mode; Kenko 20mm macro automatic extension tube; Canon EF100mm f/2.8L Macro lens (set for manual focus); Canon MT-26EX-RT Macro Twin Lite set for “Master” mode, and Canon 580 EX- and Canon 580EX II Speedlites set for “Slave” mode. A Sunpak LED-160 Video Light (with a white translucent plastic filter) was used to add soft light to the underside of the white “stage” used for posing the specimen.

Adobe Photoshop CC 2017 was used to create the focus-stacked composite image from five photos.

Copyright © 2018 Walter Sanford. All rights reserved.

Tags: Amherst County, exuvia, focus stacking, gear talk, Otter Lake, Virginia