Notes from Underground:pictures

Notes from
Underground

Methods and Madness

High Resolution Macro Photography

Greetings ant studiers. In case you haven't seen or heard about automontage images of small insects, here is a short update. You can see examples of automontage images of ants at the Ants of Costa Rica website, www.evergreen.edu/ants (the home page has some shortcuts to species with automontage images). This imaging technology will revolutionize the way insect taxonomy is carried out and communicated. For the first time images of small insects are almost as good as the specimen itself, and details of pilosity, surface sculpture, and color can be compared between an image on a screen and a specimen under your scope. There are actually two bits of technology involved in improving images, one very low-tech and one very high-tech.

The low-tech change has to do with lighting. Many of us are used to using incandescent bulbs, either in old-fashioned microscope lights or in fancy fiber optics light sources. On our shiny little ants glare is a significant problem that often obscures details of surface sculpture. Phil Ward recently discovered that a high-intensity flourescent light source made a much flatter and more diffused light that was a great improvement over the fiber optics light sources. A perfect source was the "Bookworm" reading light that comes with a convenient little clamp. Another convenience is that it costs about $15, instead of the $500 for a fiber optics source. I went hunting around my local office supply stores until I found them, then bought about a dozen.

Processed without automontage

Processed with autmontage

Without automontage

With automontage

Lisa Ann McNeil of Syncroscopy (see below) discovered another great trick. If you take an ordinary styrofoam cup, cut off and discard the bottom so you are left with a tapered cylinder of styrofoam, set that over your specimen on the dissecting scope stage, and direct the light pipes of a fiber optics source so that they are horizontal with the light just grazing the rim of the styrofoam, it makes a terrific diffused light. Convince yourself by looking at an ant with the light source shining directly on the specimen, then put the cup over it and rearrange the pipes. This is not good for ordinary dissecting scope work where you are constantly moving and switching specimens, but it is great for taking digital images. Styrofoam cups are often free just down the hall around the coffee pot.

Now, the automontage itself; what all the fuss is about. This is a piece of software that receives a stack of digital images, examines each one for areas that are in focus (the algorithm for how it does this is part of the trade secret that makes the software so pricey), then stiches all the in-focus bits together to make one image. In effect it allows you to make an image with as much depth of field as you want.

The setup I have now is marketed by a company called Syncroscopy. The hardware is comprised of a Leica MZ16 dissecting scope with axial carrier, a motorized z-axis (focusing) drive, a JVC-KYF70B digital camera mounted on the scope, and a PC with the automontage software. The way it works is I put a specimen on the stage, using a live image on the computer screen I get the specimen oriented the way I want it and get the lighting right (these are the most time-consuming steps), focus to the uppermost focal plane I want to capture and click a dialog box on screen to set it, focus to the lowest focal plane I want and click to set it, choose the number of steps or images I want between those two points (usually 10 images is sufficient), click Capture, lean back a few seconds while the motor drive takes over, after the ten images are captured (about 10 seconds) I click the automontage button and wait while the montaged image appears before my eyes (the exciting part). I can obtain about ten montaged images per hour.

A major issue for the average entomologist is that this setup costs considerably more than a styrofoam cup. The software by itself is many thousands of dollars. However, it can be purchased and used as a stand alone product. It does not have to be linked to a particular camera/z-stepper/scope combination. If you have your own scope and digital camera, you can use manual focus to obtain a stack of images, then import them into the automontage program. Actually, if you are incredibly patient you can make your own automontage images in Photoshop by putting all the images in as layers and erasing the parts of each layer that are out of focus (Piotr Naskrecki told me about this option). But it will take hours per image instead of minutes.

This "deluxe" setup described above, with the automated z-stepper and image capture, is relatively new and "hot off the press." The people who did the serious investigating and comparison shopping were Brian Fisher of the Cal Academy, Gary Alpert of the MCZ, and Piotr Naskrecki of Conservation International, and when I had some grant funds available they advised me on what equipment to purchase. They found that the best product was by Syncroscopy. Stephen McJonathan and Lisa Ann McNeil are the two Syncroscopy sales representatives and technical support personnel who have worked with us, and they are anxious to recruit more entomologist clients. I'm sure Brian, Gary, and Piotr will continue to be the point people as they ramp up for large-scale type imaging projects, and we all owe them a debt of gratitude for bringing this technology into the myrmecological arena.

John T. Longino
Lab I, The Evergreen State College
Olympia WA 98505 USA
email: longinoj@evergreen.edu
Ants of Costa Rica on the Web
Project ALAS