Life at 8X—soybean aphid

Although my first attempt at adding extension tubes to my Canon MP-E 65mm macro lens, effectively converting it from a 1–5X to a 1.7–8.0X lens, was nearly a year ago, it has only been recently that I’ve actually started experimenting with this combination to obtain high-mag photographs of very small insects in the field. The first example that I showed of such a photograph was a tiny seed weevil (Althaeus sp.) on its hibiscus host plant. I’ve since photographed a number of other insect subjects at high-mag using this setup and am getting a better feel for the capabilities—and limitations—inherent in using it. First, here is what the setup actually looks like:

Canon 50D body, MP-E 65mm macro lens on 68mm extension, MT-24EX twin flash w/ DIY diffuser.

Not the normal photo quality for this site (just a quick field setup photographed with my I-Phone), but it shows just how long the lens component becomes when fully extended to achieve 8X magnification. The camera is quite front-heavy, making the camera difficult to use hand-held, and the very shallow DOF (depth of field) due to the extreme level of magnification makes precise focusing difficult and magnifies the effect of any motion between the camera and subject. Obviously, one solution for these problems is to mount the camera on a tripod and place the subject on a stable surface; however, for reasons I’ve mentioned elsewhere, it is unlikely that I will ever take to bringing a tripod into the field, and the whole point of this exercise is to develop the capability for getting usable hand-held field photographs no matter what level of magnification they may require. As an alternative, I use a number of other techniques, discussed in my prior post on the subject, to stabilize the camera without using a tripod.

One of the recent subjects I photographed with this setup is the soybean aphid, Aphis glycines (order Hemiptera, family Aphididae). This distinctive Asian species has recently established in the U.S. as invasive pest of soybeans; adult females measure only 1–2 mm in length (and the nymphs are even smaller) and can quickly develop very high densities on the leaves and upper stems of soybean plants. The following photograph was taken at the camera setup’s minimum magnification of 1.7X and provides a typical view of adult aphids and their progeny:

Aphis glycines (soybean aphid) | Warren Co., Illinois

While the above photograph does a very good job of showing the colonial appearance of infestations by these aphids on soybean foliage, what about the aphids themselves? It would be nice to get a better look at individual aphids. The following photographs were all taken with the lens fully extended to achieve 8X magnification (and completely hand-held):

Adult female aphid—note the eye spots of the unborn nymphs visible within the body.

Another adult female navigates the hairs on the surface of the soybean leaf (I never knew soybean leaves were so hairy!).

A mother surrounded by her progeny. As above, eye spots of unborn nymphs can be seen inside her body.

These photographs are not without their problems—they are a bit soft, probably due to motion blur that results from the camera being hand-held and the extremely thin DOF that makes it difficult to get all of the desired components of the photos equally in focus. Lighting also is a challenge, as the very small subject-to-lens distance forces light from the flash to come from directly above or even behind the subject while minimizing front lighting (especially evident in the last photo with its straight down view). Nevertheless, these are decent, usable photographs that provide an uncommon view of these exceedingly tiny insects—without the encumbrance of carrying a tripod in the field, the time investment of studio photography and/or focus-stacking, or the expense of a microscope-mounted camera system (for those of us without access to such systems).

Copyright © Ted C. MacRae 2012

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About Ted C. MacRae

Ted C. MacRae is a research entomologist by vocation and beetle taxonomist by avocation. Areas of expertise in the latter include worldwide jewel beetles (Buprestidae) and North American longhorned beetles (Cerambycidae). More recent work has focused on North American tiger beetles (Cicindelidae) and their distribution, ecology, and conservation.
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10 Responses to Life at 8X—soybean aphid

  1. These are absolutely beautiful. I can’t wait to see more!

  2. Oscar Cole says:

    Stumbled across your site, when using this setup how did you deal with the aperture? Did you sacrifice some diffraction for some DOF? I have used this same setup as you, just wondering what settings you were using.

  3. Great shots Ted! What are your flash and exposure settings at 8x mag.? I want to try this out someday.

  4. I guess I could have mentioned the camera/flash settings that I’m using, but they are similar to what I would use at lower mags: ISO 100, 1/250 sec, f/13, and -1/3 FEC with E-TTL. I probably should open up the aperture a bit but wanted to try for as much DOF as possible.

    The difficulties in lighting probably account for the softness as well, since the closer you can get the light to the subject the shorter the resulting flash duration (flash intensity does not change, only its duration – thus, your virtual shutter speed increases with shorter flash duration). My flash heads were ~2 inches above the diffuser, so the resulting longer flash duration may have allowed some motion blur. If you can figure out a way to get the flash heads right on top of the subject that would improve the sharpness.

  5. Very cool and very well done Ted. Now you just need to add a 2x teleconverter on there and get 16x in utero photos of those developing nymphs!

  6. Gustavo says:

    Ted, these pictures are fantastic! The field of trichomes that the poor gal has to navigate in pictures 2 and 3 adds some drama too. But the eyes of the unborn nymphs take the prize.

  7. fayemerrill says:

    Amazing photographs; clever solution to getting up close to tiny creatures. Fascinating. Have been reading your well written blog for over a year & felt it time to speak & thank you for scholarly effort.

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