Having imaged a number of amber fossils for an upcoming publication, I thought it might be good to summarize the workflow I have been using with my equipment in a blog post. Here it is in images and short captions.
- Stereo microscope: Zeiss SteREO Discovery.V12 (Zeiss web-site), PlanApo S 1x objective, Zeiss VisiLED illumination, magnification varies.
- Camera: Micro 4/3 Olympus OM-D E-M5 (see dpreview.com for details) - I have also used an Olympus E-PL5 with this stereo microscope.
- Settings camera: S program, shutter time = 1/125, RAW image, low ISO (= 100), auto White Balance.
- Settings VisiLED lightsource: combined/mixed Bright Field (light from above) and Dark Field (light from side) - in some instances also Transillumination (light from below).
- Image stacking: manual, 15–30 slices/images per specimen.
- Software: Adobe Lightroom 5, HeliconFocus Pro 6. The workflow below is entirely RAW-based - RAW-in-DNG-out.
1. Specimen, here †Protoloewinella keilbachi Schumann, 1984 (Asilidae: Laphriinae: Atomosiini, K-4739), placed on stage.
3. Look into the "light chamber" that will go over the specimen. The lower ring of LED lights (closest here) will provide the Dark Field (lateral) light and the 2nd set of LED lights (two rings, further away surrounding the objective opening) will provide the Bright Field (dorsal) light.
4. The specimen is covered/surrounded by light in a "light chamber" and we are ready to take images.
5. View of the camera display with a preview of the image and camera settings
Since the Zeiss SteREO Discovery.V12 doesn't have a motor drive to move the objective/camera down to take several images at different focal plains (the V20 does), I trigger the camera with a remote control and manually move down the objective/camera before taking the next image. I try to always move it the same distance, but that's not always possible. I take between 15–30 slices/images per specimen. For higher magnification of certain parts of the specimen, the number can be smaller.
Once all of the images are taken, I use the same workflow with Lightroom and Helicon Focus as with other images I take of pinned flies. You can read more in this blog post by starting at number 17. Differences are:
- no need to rotate the images
- keywords will be the magnification setting at the stereo microscope
- no scale line (although one could add the scale line here)
A few general comments:
- the Dark Field LED lights were set to be much brighter than the Bright Field lights
- it is good to play with the transillumination - sometimes it enhanced the image and sometimes it didn't make much of a difference
- of course, one always sees more looking through the stereo microsocope than can be captured in the image, but the images provide access to these specimens and will all be uploaded and made available through Morphbank for future dipterists at publication of the manuscript.
Here are a few final images.
†Protoloewinella keilbachi (K-4739) in dorsal view. 10x magnification.
†Protoloewinella keilbachi (K-4739) in ventral view. 10x magnification.
†Protoloewinella keilbachi (K-4739) male terminalia detail with Transillumination. 60x magnification.
I have previously used the same stereo microscope, lighting set-up, and post-processing worklfow to image male and female terminalia of extant flies. See Dikow 2015.
Anasillomos juergeni Dikow, 2015 (USNMENT00832201) male terminalia dorsal. 50x magnification, Morphbank 850965.
Anasillomos juergeni (USNMENT00832201) male terminalia lateral. 50x magnification, Morphbank 850967.
Anasillomos juergeni (USNMENT00832201) male terminalia ventral. 50x magnification, Morphbank 850969.